Adirondack Journal of Environmental Studies, Volume 20 by Kelly Adirondack Center

ADIRONDACK RESEARCH CONSORTIUM

UNION COLLEGE

201 PAOLOZZI CENTER | PAUL SMITHâ&#x20AC;&#x2122;S COLLEGE

807 UNION STREET

P.O. BOX 96

SCHENECTADY, NEW YORK 12308

PAUL SMITHS, NEW YORK 12970

THE ADIRONDACK JOURNAL of Environmental Studies

THE KELLY ADIRONDACK CENTER

THE ADIRONDACK JOURNAL of Environmental Studies A JOURNAL OF THE ADIRONDACK RESEARCH CONSORTIUM

PUBLISHED BY THE KELLY ADIRONDACK CENTER AT UNION COLLEGE IN PARTNERSHIP WITH THE ADIRONDACK RESEARCH CONSORTIUM

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20 THE ADIRONDACK JOURNAL of Environmental Studies PROUD MEMB

A JOURNAL OF THE ADIRONDACK RESEARCH CONSORTIUM

PUBLISHED BY THE KELLY ADIRONDACK CENTER AT UNION COLLEGE IN PARTNERSHIP WITH THE ADIRONDACK RESEARCH CONSORTIUM

TABLE OF CONTENTS

1: INTRODUCTION

David J. Miller 2: THE SUMMER BIRDS OF THE ADIRONDACKS IN FRANKLIN COUNTY, N. Y.: A CHECKLIST

Originally published by Theodore Roosevelt and H. D. Minot (1877) 3: CONSERVATION THROUGH THE LIVES OF ADIRONDACK LOONS: AN OVERVIEW OF BRI’S ADIRONDACK CENTER FOR LOON CONSERVATION

Nina Schoch 4: THE ADIRONDACK ARCHIPELAGO

Jeremy Kirchman and Joel Ralston 5: BIRDS OF THE ADIRONDACKS

Photography by Larry Master 6: OCCUPANCY, DETECTION, AND CO-OCCURRENCE RATES OF AMERICAN BLACK AND MALLARD DUCKS IN THE SARANAC LAKES WILD FOREST AREA

Gary A. J. Macy and Jacob N. Straub 7: STATE OF THE BIRDS IN EXURBIA

Michale J. Glennon and Heidi E. Kretser 8: THE SARANAC LAKE CHRISTMAS BIRD COUNT: A 60-YEAR RECORD OF WINTER BIRD POPULATIONS IN THE CENTRAL ADIRONDACKS

Larry Master 9: RUSTY BLACKBIRDS IN NEW YORK STATE: ECOLOGY, CURRENT STATUS, AND FUTURE

Stacy McNulty, Michale J. Glennon, and Melanie McCormack 10: THE BIRDSBESAFE ® CAT COLLAR COVER: WHY CATS IN NEW YORK NEED IT MORE THAN AUSTRALIAN CATS TO DECREASE SONGBIRD MORTALITY

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Susan Willson 11: NORTHERN NEW YORK AUDUBON: ORGANIZATIONAL PROFILE

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John Thaxton 12: BIODIVERSITY RESEARCH INSTITUTE: SONGBIRD RESEARCH FROM SPHAGNUM BOG TO ALPINE SUMMIT

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Amy Sauer and David Evers 13: CONSERVATION STATUS AND MONITORING OF BICKNELL’S THRUSH IN THE ADIRONDACKS AND NEW ENGLAND: A BRIEF REVIEW

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Michale J. Glennon and Chad L. Seewagen

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ADIRONDACK RESEARCH CONSORTIUM BOARD OF DIRECTORS Pictured top, left to right: Dave Miller, Eileen Allen, Jeff Denkenberger, Greg Slack, Hallie Bond, Caleb Northrop, and Dan Fitts. Bottom, left to right: Amanda Lavigne, Dan Spada, Stacy McNulty, Tom Young, and Liz Thorndike. Photo by Bruce Selleck.

Stephen C. Ainlay, Ph.D. PRESIDENT

Union College

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ADIRONDACK RESEARCH CONSORTIUM 2015 BOARD OF DIRECTORS

Daniel Spada

Thomas Young

PRESIDENT

VICE PRESIDENT

Tupper Lake, NY

Clarkson University

Brian Chabot

Eileen Allen

VICE PRESIDENT

TREASURER/SECRETARY

Cornell University

SUNY Plattsburgh Center for Earth & Environmental Science

BOARD MEMB E R S

S. Jeffrey Anthony The LA Group, P.C.

David Miller Ballston Lake, NY

Hallie Bond Union College, Kelly Adirondack Center

Caleb Northrop Union College, Kelly Adirondack Center

Jeffrey Chiarenzelli St. Lawrence University

William Porter Michigan State University

Jeff Denkenberger Molpus Timberlands Management, LLC

Bruce Selleck Colgate University

Curt Gervich SUNY Plattsburgh Center for Earth & Environmental Science

Gregory Slack Clarkson University

Willie Janeway Adirondack Council Amanda Lavigne Clarkson University

Elizabeth Thorndike Cornell University Daniel Fitts EXECUTIVE DIRECTOR

Adirondack Research Consortium

Stacy McNulty SUNY College of Environmental Science and Forestry, Adirondack Ecological Center

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THE ARC RECOGNIZES AND THANKS OUR 2015-16 PARTNERS AND SPONSORS

LEADING PARTNER:

CONTRIBUTING PARTNERS:

Iberdrola USA

Adirondack Council

SUSTAINING PARTNERS:

Brookfield Renewable Power New York State Energy Research and Development Authority

Adirondack Museum Adirondack Nature Conservancy Placid Productions Open Space Institute

Paul Smith’s College

Wild Center

The Rockefeller Institute of Government

LOCAL GOVERNMENT PARTNERS:

SUNY-College of Environmental Science and Forestry

Adirondack Park Local Government Review Board

SPONSORING PARTNERS:

Town of Newcomb

Ecology and Environment, Inc.

PARTNERS:

Empire State Forest Products Association

Adirondack Community College

SUPPORTING PARTNERS:

Adirondack Wild

Boquet Foundation

International Paper’s Ticonderoga Mill

Clarkson University

North Country Community College

Colgate University

Adirondack North Country Association

National Grid

Adirondack Park Institute, Inc.

Northern New York Audubon

Audubon New York

St. Lawrence University

Integrated Science LLC

SUNY Plattsburgh

Wildlife Conservation Society

Union College University of Vermont FOUNDATION SPONSORSHIP PROVIDED BY:

Cloudsplitter Foundation

Adirondack Lakes Survey Corporation

ASSOCIATE PARTNERS:

Mountain Lake PBS NYS Olympic Regional Development Authority

Colgate Upstate Institute– Colgate University Glenn and Carol Pearsall Adirondack Foundation International Paper Foundation PUBLISHING OF VOLUME 20 OF AJES WAS ALSO MADE POSSIBLE WITH A NORTHERN NEW YORK AUDUBON CULLMAN GRANT AND WITH GENEROUS CONTRIBUTIONS BY LARRY MASTER AND MARGOT ERNST.

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ADIRONDACK JOURNAL OF ENVIRONMENTAL STUDIES Caleb Northrop EXECUTIVE EDITOR

Union College, Kelly Adirondack Center 807 Union Street, Feigenbaum Hall, Schenectady, NY 12308 Stacy McNulty ASSOCIATE EDITOR

SUNY College of Environmental Science and Forestry Adirondack Ecological Center, 6312 State Route 28N, Newcomb, NY 12852 Daniel Fitts MANAGING EDITOR

Adirondack Research Consortium 201 Paolozzi Center, Paul Smith’s College, P.O. Box 96, Paul Smiths, NY 12970

MISSION STATEMENT

The Adirondack Journal of Environmental Studies (AJES) exists to foster a dialogue about the broad range of issues that concern the Adirondacks and Northern Forest. AJES serves to bridge the gaps among academic disciplines and among researchers and practitioners devoted to understanding and promoting the development of sustainable communities, both human and wild. The journal purposefully avoids serving as a vehicle for any single or special point of view. To the contrary, in searching for common ground AJES welcomes variety and a broad spectrum of perspectives from its contributors.

CONTRIBUTING TO AJES

We encourage the submission of manuscripts, reviews, photographs, artwork, and letters to the editor. For additional information please visit the AJES website at www.ajes.org.

BLACK & WHITE PHOTOGRAPHY: MATT MILLESS / MAHIMATTPHOTO THE VIEWS EXPRESSED IN AJES ARE THE AUTHORS’ AND NOT NECESSARILY THOSE OF THE EDITOR, PUBLISHER, UNION COLLEGE, OR THE ADIRONDACK RESEARCH CONSORTIUM. ISSN: 1075-0436 ©2015

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INTRODUCTION DAV ID J. MILLER

ARC Board Member and Former Executive Director of Audubon New York

Over a hundred and fifty years ago, a young man traversed the woodlands of the Adirondacks fueling his passion for conservation while searching for as many bird species as he could document. The task in hand was a passion of his, as it remains for many birders today. The man, Theodore Roosevelt, Jr., was joined by his friend and colleague H.D. Minot on their quest to explore New York’s great and rugged forest landscape of the Adirondacks. Together, they wrote their summer observations and subsequently identified over 97 species of birds between August of 1874 and July of 1877. They published their findings and conclusions in a pamphlet titled The Summer Birds of the Adirondacks in Franklin County, New York, with which we begin this special avian issue of the Adirondack Journal of Environmental Studies. Roosevelt and Minot recalled the conditions of each of their sightings of a wide variety of birds, from Common Loons to a host of interior forest warbler species. They listened to the calls of thrushes in the day and the echoes of a variety of owls in the evening. Hiking in the St. Regis Lakes region, they commented on what they believed were common sightings as well as those rare to the area. They recounted the locations of breeding areas as well as stopover locations for birds passing through on their own journey. As you enjoy this edition of AJES containing avian findings of today’s scientists and reports on the conditions of today’s Adirondack forests, you can travel back to the days of the nation’s greatest conservation hero and relive his enthusiasm and love for nature. While some of the names may have variations from modern usage, the observations remain valuable. This edition of AJES is dedicated to the birder Teddy Roosevelt. Following his inspiration, let’s ensure his sightings as well as ours today contribute to a better understanding of the avian world.

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THE SUMMER BIRDS OF THE ADIRONDACKS IN FRANKLIN COUNTY, N.Y.: A Checklist ORIGINALLY PUBLISHED BY THEODORE ROOSEVELT AND H.D. MINOT (1877)

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Roosevelt, T.R. 1877. “The Summer Birds of the Adirondacks in Franklin County, N.Y.,” Naturalists’ Agency (Samuel E. Cassino, Pub.). New York State Library Special Collections.

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CONSERVATION THROUGH THE LIVES OF ADIRONDACK LOONS: An Overview of BRI’s Adirondack Center for Loon Conservation NINA SCHOCH

Coordinator, BRI’s Adirondack Center for Loon Conservation, PO Box 195, Ray Brook, NY 12977 nina.schoch@briloon.org, 888-749-5666 x145

The Biodiversity Research Institute’s (BRI) Adirondack Center for Loon Conservation conducts conservation research and outreach focusing on the Common Loon (Gavia immer) in New York State’s six million acre Adirondack Park. Hundreds of Adirondack lakes and ponds provide critical breeding habitat for Common Loons during the summer months, as well as an excellent opportunity to study these unique birds and learn more about their populations. In 1998, as part of a larger regional study, the Biodiversity Research Institute (BRI) initiated research in the Adirondacks on the impact of airborne pollutants, particularly mercury emissions and acid deposition, on aquatic ecosystems, using the Common Loon as an indicator species. This work evolved into the development of BRI’s Adirondack Center for Loon Conservation, which is dedicated to enhancing the overall health of the environment through applied research and education efforts utilizing the Common Loon as a sentinel of aquatic ecosystems. The Biodiversity Research Institute is dedicated to supporting global ecological health through collaborative research, assessment of ecosystem health, improving environmental awareness, and informing science-based decision making. With more than 150 projects worldwide, BRI works to assess emerging ecological threats, raise awareness, and inform policymakers, leading to enhanced environmental protections. BRI’s Adirondack Center for Loon Conservation merges the worlds of field research and outreach to expand public

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awareness and understanding of Common Loon natural history and conservation, and to inspire science-based conservation strategies to better protect environmental health in and beyond New York’s Adirondack Park. The primary goals of BRI’s Adirondack Center for Loon Conservation are to: 1. U se the Common Loon as an indicator species in our scientific research to identify and address conservation threats impacting the Adirondack breeding loon population and aquatic ecosystems. 2. Provide objective information to the public and scientific communities to increase awareness and understanding of loon natural history and regional conservation issues so as to minimize anthropogenic threats affecting wildlife populations and the environment. 3. Inspire the public and students to become directly involved in wildlife conservation through opportunities to participate with BRI’s Adirondack Center for Loon Conservation’s research and outreach programs. 4. P rovide sound scientific information to the public, scientists, and legislators to enable them to make informed decisions regarding the management of wildlife species, regulation of airborne pollutants, and the long-term protection of freshwater ecosystems in the Adirondack Park. Through scientific research and outreach programming, the Adirondack Loon Center addresses conservation threats to both individual loons, such as fishing line entanglement and nest disturbance, and to the Adirondack population as a whole, such as environmental contamination by airborne pollutants. The Loon Center’s research is designed to learn more about the natural history of and threats affecting the Adirondack breeding loon population. Current studies include investigating the impacts of mercury pollution and acid deposition to the Adirondack loon population; assessing the health of Adirondack loons; identifying their migratory patterns and wintering areas; determining the status and trends in New York’s breeding loon population; and determining factors affecting nesting and hatching success. The Adirondack Loon Center collaborates with numerous partners in its research studies, including the NYS Department of Environmental Conservation, the Wildlife Conservation Society, SUNY ESF’s Adirondack Ecological Center, and the Adirondack Watershed Institute. Financial support for BRI’s Adirondack Center for Loon Conservation is generously provided by the New York State Energy Research and Development Authority, as well as numerous foundations and private donors. This financial and in-kind support has contributed to significant insight into Adirondack loon ecology, movements, and distribution.

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In addition to the Center’s work in New York State, the Adirondack loon research is coordinated with similar studies across North America to better understand loon populations throughout their entire range. This continental scope provides a scientific basis to help guide conservation efforts by increasing awareness of human-related and natural threats to wildlife and the environment. These studies provide policy-makers with critical scientific information for making informed decisions about essential regional, national, and global environmental protections—including monitoring and regulating emissions of anthropogenic pollutants— based on the health and reproductive success of the Common Loon, an iconic symbol of freshwater ecosystems in North America. The results of the Loon Center’s investigations also contribute to sustainable management of the species in New York State and across the continent. BRI’s Adirondack Loon Center integrates its innovative scientific research with inspiring educational programs to address critical conservation issues affecting the Common Loon population and its freshwater habitats in the Park itself. The captivating nature of Common Loons is employed in the Loon Center’s educational and outreach programming to advance both public and scientific knowledge of Common Loon conservation. The goal of the Loon Center’s outreach programming is to minimize human impacts on loon populations, other wildlife, and their habitats. The Center’s scientific findings are translated into a variety of outreach materials, including technical and lay-audience reports, brochures, and scientific publications; interactive public and scientific presentations; an annual newsletter, The Adirondack Tremolo; innovative school curricula (e.g., Science on the Fly!) which actively engage students in environmental conservation; an informative website and Facebook page (www.briloon.org/adkloon and www.facebook.com/adkloon); educational signs at boat launches; and community events (e.g., the Adirondack Loon Celebration). With the goal of enabling humans to live compatibly with wildlife in a healthy environment, Adirondack residents and visitors are enlisted to help apply the knowledge that has been learned through the Loon Center’s scientific studies. The Loon Center conducts a variety of projects and events, such as our fishing line recycling program, to allow interested citizens to directly participate in the conservation of loons and their aquatic habitats in the Adirondack Park. The Center also provides a variety of field, internship, and volunteer opportunities for college students and community members to obtain first-hand experience and training in wildlife research, conservation, and outreach. For younger students (elementary, middle, and high school), interactive school curricula are available through the Adirondack Loon Center’s website as an engaging resource for learning about Adirondack loons and the connections between humans and the environment.

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A long-term goal of BRI’s Adirondack Center for Loon Conservation is to become a self-sustaining conservation entity in the Adirondack Park. Future plans include the establishment of a physical office space in the Tri-Lakes area of the Park to accommodate a growing staff. The vision for a physical Adirondack Loon Center is multifold. Along with accommodating a larger staff, the Center will serve as an exciting regional tourist attraction with a modest environmental education facility including interactive displays about loon natural history, behavior, and loon conservation concerns. A meeting room will be available to offer workshops and training programs about loon natural history, conservation of loon populations, and wildlife research. Plans also include a loon-oriented retail shop to enable visitors to obtain unique artisanal items in the theme of our distinctive Adirondack icon. An increase in BRI’s Adirondack Center for Loon Conservation staff and a new physical location will greatly facilitate the Center’s ability to enhance its collaboration with other Adirondack and regional scientists, organizations and educational institutions, such as the Wildlife Conservation Society, The Wild Center, SUNY ESF’s Adirondack Ecological Center, Paul Smith’s College, Syracuse University, and the NYS Department of Environmental Conservation. The Center’s training and outreach capacity will similarly improve, increasing the opportunity for regional students of all ages to become directly involved in environmental conservation. Finally, the physical Loon Center will showcase Adirondack loons as “ambassadors” in the Center’s displays and other outreach materials to enable students world-wide to learn about environmental conservation and wildlife through the lives of this beautiful and charismatic symbol of New York’s Adirondack Park. To learn more about BRI’s Adirondack Center for Loon Conservation, visit www.briloon.org/adkloon, www.facebook. com/adkloon, or contact adkloon@briloon.org or PO Box 195, Ray Brook, NY 12977.

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THE ADIRONDACK ARCHIPELAGO JEREMY J. KIRCHMAN 1 AND JOEL RALSTON 2,3

1. New York State Museum, 3140 Cultural Education Center, Albany, NY 12230. jeremy.kirchman@nysed.gov 2. Department of Environmental Conservation, University of Massachusetts, 160 Holdsworth Way, Amherst, MA 01003 3. Current address: Department of Biology, Saint Mary’s College, Notre Dame, IN 46556

The Adirondacks comprise an uplifted, highly dissected dome of Canadian Shield rocks that formed between 880 million to 1.1 billion years ago (Wiener et al. 1984). This dome of ancient rock rose up and out of the surrounding strata of Paleozoic bedrock a mere 5.5 million years ago, forming a well-circumscribed mountain range that rises to a maximum elevation of 1629 m. Thus, to geologists, the Adirondacks are relatively new mountains made of very old rocks, an easily accessible window into the deep past of North America, and a trove of mineral riches. To biologists the Adirondacks are no less interesting, and for a similar reason. Just as the ancient basement rocks of North America protrude like an island above the surrounding sea of younger rocks, so too does a distinct ecosystem. The evergreen-dominated boreal forest that stretches from Alaska to the Canadian Maritimes protrudes on Adirondack mountains above the surrounding deciduous forests that dominate the landscape elsewhere in New York and New England. Sitting at 43° N - 45° N latitude, the Adirondacks are an isolated southern outpost of the boreal forest biome that, at lower elevations, reaches its southern boundary north of us at 48° N - 50° N (Figure 1). Species that are adapted to the moist, cool climate of the boreal forest occupy two distinct habitat types in the Adirondacks, as defined by the comprehensive Northeast Terrestrial Habitat Classification System: Boreal Upland Forest, and Northern Peatland (NETHCS, available at www.conservationsgateway.org). Boreal Upland Forest is the spruce (Picea) and fir (Abies) dominated forest one finds on mountain slopes from 850 m—1450 m (Whitehead

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and Jackson 1990). It comprises 11% of the area of the Adirondack Park, whereas Northern Peatlands, the bogs and fens found at lower elevations, comprise only 1% of the Park (Glennon and Curran 2013). Both of these habitat types are naturally patchy, making the Adirondacks more like an archipelago than a single island of boreal habitat. Boreal forest specialists in the Adirondacks are therefore distributed in disjunct “island” populations, isolated from one another and from the contiguous boreal forest farther north. To a biologist, the Adirondacks are an archipelago of isolated habitat islands, a natural laboratory for studying ecology and evolution. Biologists studying life on islands have contributed much to our understanding of how evolution works. Charles Darwin and Alfred Russel Wallace independently developed the theory of natural selection by studying the subtle differences between populations from different oceanic islands (Darwin 1859). They both noted that birds often differ in color or body size from island to island, indicating that isolated populations may be evolving independently of one another, adapting to the local conditions. The patterns they observed as they traveled and collected specimens in the Galapagos Islands and the Indo-Pacific revealed to them the primary mechanisms of evolution and the importance of isolation in generating biodiversity. In the 150 years that have followed Darwin and Wallace’s discovery, the study of geographic patterns of variation among isolated populations has become a foundation of our current understanding of how new species are formed, and how they are lost to extinction (Mayr and Diamond 2001, Steadman 2006, Price 2008). Geographically isolated populations of the same species may evolve to become genetically or physically distinct depending on the relative connectivity among populations (Avise 2004). Interbreeding between populations, what population biologists call “gene flow,” will preserve the similarities among isolated populations. Population biologists are therefore interested in the amount of genetic diversity and the relative levels of divergence versus gene flow among geographically disjunct populations such as those on archipelagos. Populations with low levels of genetic diversity may suffer from increased inbreeding depression, decreased reproductive fitness, and increased extinction risk (Westemeier et al. 1998, Frankham 2005). Conservation efforts focused on disjunct populations therefore often aim to promote genetic diversity or conserve genetically unique conservation units (Moritz 2004). The genetics of species living in “sky island” archipelagos like we find in the Adirondacks have been well studied in the Rocky Mountains, the European Alps, in tropical montane forests in the Andes, and in the American Southwest where pinion-juniper forest is found on mountain slopes above the surrounding desert (Bech et al. 2009, DeChaine and Martin 2005, McCormack et al. 2008, Knowles 2000, Särkinen et al. 2012). Despite their promise as a sky island study system, the Adirondacks are understudied by evolutionary biologists,

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and little is known regarding patterns of genetic divergence among Adirondack bird populations. Within the last few years, our genetics research at the New York State Museum and by ornithologists at other institutions has begun to reveal the evolutionary history and relationships among bird species within the Adirondack archipelago. In the sections that follow, we describe some of the results of this ongoing research, focusing on these questions: (1) Are Adirondack populations of boreal forest birds genetically distinct from other populations? (2) Do different bird species share similar biogeographic histories? and (3) How is climate change likely to influence the genetic diversity of Adirondack birds? The work of answering these questions begins in the field, where wild birds from different mountains or bogs in the Adirondacks and from neighboring mountain ranges are captured, and small tissue samples (blood or feathers) are preserved for analysis in the genetics lab. DNA is extracted from tissues, specific genes with known rates of mutation are isolated from each bird’s genome, and the sequence of its DNA nucleotides is determined biochemically. Finally, the gene sequences from all the birds are compared for differences and birds are grouped by which version of the gene (allele) they are carrying. Birds whose sequences are identical at all nucleotides are said to share the same allele. Population level diversity is measured by calculating the number of alleles in the sample and the number of “private alleles,” which are those that are found only in one geographic population.

ARE ADIRONDACK POPULATIONS OF BIRDS GENETICALLY UNIQUE? Genetic research targeting a well-studied gene from the mitochondrial genome, the control region, has been conducted for three species that have been sampled from multiple sites in the Adirondacks: Spruce Grouse (Falcipennis canadensis) (Kirchman, unpublished data), Boreal Chickadee (Poecile hudsonicus) (Lait and Burg 2013) and Blackpoll Warbler (Setophaga striata) (Ralston and Kirchman 2012). Patterns of variation in the mitochondrial control region for these species are summarized in Table 1. The contrasting levels of genetic diversity and distinctiveness of the Adirondack populations demonstrate the different ways that wild populations can be genetically structured. The Adirondack population of Spruce Grouse is unique, with very low genetic diversity. Of the 22 individuals sequenced, we found only 3 alleles, and all three of these were private to the Adirondacks, meaning they were not found in neighboring populations. Spruce Grouse from Vermont, Maine, and Ontario, however, were more diverse with almost every individual being genetically distinct. These results indicate to us that Adirondack Spruce Grouse are reproductively isolated from neighboring populations. The low level of heterozygosity (h) in this population suggests a genetic “bottleneck” that likely results from the well-documented decline of the Adirondack population over the last 100+ years (Ross and Johnson 2012). Conservation actions aimed at increasing genetic diversity in Adirondack Spruce Grouse, including the current program of translocation of birds from outside populations by the NYSDEC, might be beneficial and could stave off extirpation of this population.

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Blackpoll Warblers, on the other hand, are equally diverse in the Adirondacks and in surrounding populations in the Northeast, and the Adirondacks hold very few unique alleles for this species (Table 1). Blackpoll Warblers from the Adirondacks have nearly three times the level of heterozygosity of Adirondack Spruce Grouse, whereas both species have high heterozygosity in neighboring populations. This suggests that geographically isolated Blackpoll Warbler populations, unlike Spruce Grouse, are genetically well connected with gene flow occurring regularly. The Adirondack population of the Boreal Chickadee is intermediate to extremes exemplified by Spruce Grouse and Blackpoll Warbler. Boreal Chickadees have lower genetic diversity in the Adirondacks than in neighboring populations, but the reduction is much less drastic than that seen in Spruce Grouse. These different patterns across species may be related to the relative isolation of the habitat types preferred by each species, to their different migratory behaviors, or to the different effective population sizes of these species in the Adirondacks. The Spruce Grouse is a rare, non-migratory resident species that prefers Northern Peatlands, while Blackpoll Warblers are long-distance migrants found in high abundance in the Boreal Upland Forest. Not surprisingly, the Boreal Chickadee falls between these two ends of the spectrum: it is a locally common, non-migratory resident species that can be found in both Northern Peatlands and the Boreal Upland Forest. It is possible that the small area and greater isolation of Northern Peatlands has contributed to the genetic isolation of its bird populations, compared to Boreal Upland Forests which have a greater area and may be more spatially connected. Alternatively, the long distance migratory behavior of Blackpoll Warblers may give this species stronger dispersal abilities compared to the non-migratory Spruce Grouse and Boreal Chickadee. Ongoing work in our lab is aimed at testing these alternative hypotheses by analyzing a larger sample of genetic data from Boreal Chickadees and additional species such as the Yellow-bellied Flycatcher and Bicknellâ&#x20AC;&#x2122;s Thrush. Both the Yellow-bellied Flycatcher and Bicknellâ&#x20AC;&#x2122;s Thrush are migrant species of the Upland Boreal Forests, and the former also breeds in Northern Peatlands.

DO DIFFERENT BOREAL BIRD SPECIES SHARE SIMILAR BIOGEOGRAPHIC HISTORIES? Much like Adirondack geology, Adirondack biota and genetic patterns held within them can offer a glimpse into the history of North America. Intermittently throughout the glacial cycles of the last two million years, vast portions of North America were covered in boreal forests similar to those that remain in the Adirondacks (Whitehead and Jackson 1990). As forests expanded and contracted across the landscape, boreal bird populations were reconfigured, combining at times into large contiguous populations, followed by periods during which populations were sundered into smaller isolates. Animal populations

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still retain the signature of these historic distributional changes in their genomes, and we can use genetic patterns found in modern populations to understand the timing and the path by which different species came to occupy their current distributions (Avise 2004). This approach, known as comparative phylogeography, aims to understand how and why genetic patterns differ across species (Zink 1996). Whereas in the previous section we interpreted differences in the genetic patterns of Spruce Grouse, Boreal Chickadee, and Blackpoll Warbler in terms of modern gene flow and isolation, comparative phylogeography uses genetic variation sampled throughout species’ ranges to infer the extent to which biogeographic histories are shared among different species. Here we are interested in comparing genetic patterns across boreal bird species to understand whether these species survived the Pleistocene in different places and how long these species have co-occurred in the Adirondacks. Phylogeographic studies have been published for seven species of boreal forest birds that breed in the Adirondacks, and the patterns observed are as diverse as the species themselves. Our work on Blackpoll Warblers shows that all modern populations of this species, including those as far away as Alaska, are descendent from a single, Late-Pleistocene population that was likely located in eastern North America south of the ice sheet at the last glacial maximum (Ralston and Kirchman 2012). Studies of other boreal species have differed in the number and location of inferred ancestral populations that dwelled in Pleistocene refugia (Brelsford et al. 2011, Burg et al. 2014, Milá et al. 2007, Ruegg et al. 2006, van Els et al. 2012). A split into eastern and western refugia has been suggested for Boreal Chickadee (Poecile hudsonicus), Golden-crowned Kinglet (Regulus satrapa), and Swainson’s Thrush (Catharus ustulatus), and multiple refugia are also likely for the Yellow-rumped Warbler species complex (Setophaga coronata). Despite the different number of inferred refugia in these species, they may have colonized the Adirondacks at similar times given that they all persisted in eastern North American refugia. Gray Jay (Perisoreus canadensis) and Dark-eyed Junco (Junco hyemalis), on the other hand, are suggested to have survived the Pleistocene in a single or multiple southwestern refugia and expanded into their current distribution by first colonizing northern regions of western North America and later expanding eastward from the western boreal forest (Milá et al. 2007, van Els et al. 2012). Together, these results suggest that the Adirondack avifauna may have been pieced together at different times and via different routes. The community of boreal bird species that inhabit the Adirondack Archipelago today has changed in response to past climate changes and is expected to change further in response to anthropogenic climate warming in the coming century. Let us now turn to our final research question and combine predictive models of climate change with what we know about genetic diversity.

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HOW WILL CLIMATE CHANGE INFLUENCE THE GENETIC DIVERSITY OF ADIRONDACK BIRDS? As global climates warm, North American birds are shifting their distributions to higher latitude and higher elevation to track suitable conditions (Tingley et al. 2009, Zuckerburg et al. 2009, Auer and King 2014). Adirondack populations of boreal forest birds already located at high elevations and at the southern edge of speciesâ&#x20AC;&#x2122; ranges may be especially vulnerable to climate change as warming threatens to push these species out of the Adirondack archipelago. Analysis of long-term bird population trends shows that several boreal forest specialists are already declining at the southern periphery of the boreal forest (Ralston et al. 2015). To the extent that isolated, peripheral bird populations are genetically distinct, climate change may threaten genetic diversity and increase extinction risk. To examine this potential we have used computer models of boreal bird species distributions to predict whether mountain populations found in New York and neighboring states will be extirpated in the current century. These models overlay maps of current species occurrences with maps of climatic conditions (various measures of temperature and precipitation) and then use predicted climate conditions to project where a species will likely be distributed in the future. Finally, we combine these modeled distributions with our genetic data to predict whether climate change will have significant effects on the genetic diversity of boreal birds. We have modeled the distribution of 15 boreal forest bird species to the year 2080 to predict the extent to which ranges will shift, leading to the extirpation of isolated populations at the southern periphery of the boreal forest (Ralston and Kirchman 2013). Our climate-based distribution models predict substantial range shifts to the north and northwest up to 1400 km, and that nearly all 15 species we modeled will be extirpated from high elevations in New York, Vermont, and New Hampshire by 2080 (Table 2, Figure 2). It is important to note that these models are based only on predicted climate change and that habitats may change more slowly than climate, allowing birds to persist in mountain populations longer than predicted by climate alone. Climate-only distribution models probably are worst-case scenarios, and some species will surely tolerate the changes better than others. These predictions are nevertheless alarming, as they suggest the possibility of whole-scale faunal turnover at the southern edge of the boreal forest in the present century. For the species with the most comprehensive genetic sampling, the Blackpoll Warbler, we compared genetic data from mountain populations predicted to be extirpated to more northern populations predicted to persist. As noted above, the DNA data indicate that Blackpoll Warblers are highly dispersive and likely have high levels of gene flow among populations. Due to this, very few alleles in Blackpoll Warblers are unique to mountain

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populations, and population extirpations due to predicted climate change are not likely to affect heterozygosity or allelic richness significantly (Ralston and Kirchman 2013). The same cannot be said to be true for Spruce Grouse, which has a distinctive gene pool in the Adirondacks. Thus, the genetic consequences of climate change will vary across species according to their dispersal ability, history of isolation, and extent of their distribution north of the Adirondacks. Ongoing work in our labs is aimed at determining whether the predicted effects of climate change are consistent across species. One species we find particularly interesting in this regard is Bicknell’s Thrush; like Blackpoll Warbler, it is migratory and is expected to have high levels of gene flow among isolated populations. But Bicknell’s Thrush is found only in high elevation forests of the northeast United States and eastern Canada. Loss of the southernmost populations in this species may therefore represent a more significant proportion of the gene pool than for species distributed across the Canadian boreal forests such as Blackpoll Warbler. The great island biogeographer Alfred Russel Wallace wrote that the distributions of species are “in their very nature the visible outcome and residual product of the whole past history of the earth” (Wallace 1881). The bird species of the Adirondacks have much to teach us about their own evolutionary histories and about the history of the great boreal forest ecosystem. Ongoing efforts to document geographic patterns of genetic variation in Adirondack birds will, we hope, push farther open the window on the past and enable clearer views of the future of the Adirondack archipelago. Table 1. Genetic diversity of boreal forest bird species that breed in the Adirondacks. Data are DNA sequences (mitochondrial control region) obtained from multiple birds from the Adirondacks and from neighboring populations. Summary includes the length of the sequences (in base-pairs, “bp”), sample size (number of birds, “n”), number of distinct sequences identified in the sample (“alleles”), number of “private” alleles found only in the Adirondack population, and haplotype diversity (“h”), which is a measure of population level genetic diversity. Spruce Grouse and Boreal Chickadee are non-migratory, and Blackpoll Warbler migrates to the tropics for the non-breeding season.

SPECIES

ADIRONDACKS

NEIGHBORING POPULATIONS

LENGTH

ALLELES

PRIVATE

ALLELES

Spruce Grouse

1129 bp

0.255

171 14

0.971

Boreal Chickadee

776 bp

0.600

832 45

0.879

Blackpoll Warbler

355 bp

0.731

1583 41

0.813

1. Samples from Vermont, Maine, Ontario. 2. Samples from Catskills, Vermont, Maine, Quebec, New Brunswick, Nova Scotia. 3. Samples from Ontario, Quebec, New Brunswick, Nova Scotia, Newfoundland.

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Table 2. Predicted geographic shifts of entire breeding ranges (measured from the centroid of the range) and percent change in occupied area in New York, Vermont, and New Hampshire by the year 2080, for 15 boreal forest bird species. The predicted climate conditions for 2080 are from the Hadley Centre Coupled Model version 3 under carbon emissions scenario B2 of the Intergovernmental Panel on Climate Change (Intergovernmental Panel on Climate Change 2000). Data from Ralston and Kirchman (2013). SPECIES

RANGE SHIFT (km), DIRECTION

CHANGE IN AREA (%) IN NY, VT, NH

Spruce Grouse

903, NW

-99.9

American Three-toed Woodpecker

532, NW

-100.0

Black-backed Woodpecker

1160, NW

-100.0

Yellow-bellied Flycatcher

493, NW

-67.9

Gray Jay

811, NW

-100.0

Boreal Chickadee

1014, NW

-99.9

Ruby-crowned Kinglet

600, NW

-100.0

Bicknell’s Thrush

180, NW

-81.8

Swainson’s Thrush

660, NW

-98.5

Tenesee Warbler

841, NW

-80.5

Blackpoll Warbler

1408, NW

-97.4

Bay-breasted Warbler

811, NW

-50.2

Cape May Warbler

721, NW

-94.3

Yellow-rumped Warbler

833, NW

-98.7

White-throated Sparrow

615, NW

-99.3

Figure 1. Range Maps of Spruce Grouse (resident) and Blackpoll Warbler (migratory), two of the many bird species that breed throughout the huge North American boreal forest and meet the southern periphery of their ranges in the mountains of New York. Inset maps show “possible,” “probable,” and “confirmed” breeding records for each species from The Second Atlas of Breeding Birds in New York State (summarizing data collected from 2000-2005). BLACKPOLL WARBLER

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SPRUCE GROUSE

Figure 2. Modeled current diversity and predicted 2080 diversity of boreal forest bird species in New York, Vermont, and New Hampshire according to species distribution models based on climate change projections (Ralston and Kirchman 2013). Darker shading represents higher diversity. PREDICTED CURRENT DIVERSITY

PREDICTED 2080 DIVERSITY

L I TE R AT U R E C I T E D

Auer, S.K., and D.I. King. 2014. “Ecological and life-history traits explain recent boundary shifts in elevation and latitude of western North American songbirds,” Global Ecology and Biogeography, 23: 867-875. Avise, J.C. 2004. Molecular markers, natural history, and evolution. Sunderland, MA, USA: Sinauer. Bech, N., J. Boissier, S. Drovetski, and C. Novoa. 2009. “Population genetic structure of rock ptarmigan in the ‘sky islands’ of French Pyrenees: implications for conservation,” Animal Conservation, 12:138-146. Brelsford, A., B. Milá, and D.E. Irwin. 2011. “Hybrid origin of Audubon’s warbler,” Molecular Ecology, 20: 2380-2389. Burg, T.M., S.A. Taylor, K.D. Lemmen, A.J. Gaston, and V.I. Friesen. 2014. “Postglacial population genetic differentiation potentially facilitated by a flexible migratory strategy in Golden-crowned Kinglets (Regulus satrapa),” Canadian Journal of Zoology, 92: 163-172. Darwin, C. 1859. On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. DeChaine, E.G. and A.P. Martin. 2005. “Marked genetic divergence among sky island populations of Sedum lanceolatum (Crassulaceae) in the Rocky Mountains,” American Journal of Botany, 92:477-486.

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Frankham, R. 2005. “Genetics and extinction,” Biological Conservation, 126:131–140. Glennon, M., and R.P. Curran. 2013. “How Much is Enough? Distribution and protection status of habitats in the Adirondacks,” Adirondack Journal of Environmental Studies, 19: 36-46. Hewitt, G. 2000. “The genetic legacy of the Quaternary ice ages,” Nature, 405: 907-913. Intergovernmental Panel on Climate Change. 2000. IPCC Special Report: Emissions Scenarios, IPCC. Cambridge University Press, Cambridge. Knowles, L.L. 2000. “Tests of Pleistocene speciation in montane grasshoppers (genus Melanoplus) from the sky islands of western North America,” Evolution, 54:1337-1348. Lait, L.A., and T.M. Burg. 2013. “When east meets west: population structure of a highlatitude resident species, the boreal chickadee (Poecile hudsonicus),” Heredity, 111: 321-329. Mayr, E. and J. Diamond. 2001. The birds of Northern Melanesia. New York: Oxford University Press. McCormack, J.E., B.S. Bowen, and T.B. Smith. 2008. “Integrating paleoecology and genetics of bird populations in two sky island archipelagos,” BMC Biology, 6:28 doi:10.1186/17417007-6-28. Milá, B., J.E. McCormack, G. Castañeda, R.K. Wayne, and T.B. Smith. 2007. “Recent postglacial range expansion drives the rapid diversification of a songbird lineage in the genus Junco,” Proceedings of the Royal Society of London Series B 274: 2653-2660. Mortiz, C. 2004. “Defining ‘Evolutionary Significant Units’ for conservation,” Trends in Ecology and Evolution, 9:373–375. Price, T. 2008. Speciation in birds. Greenwood Village, Colorado: Roberts and Company. Ralston, J., and J.J. Kirchman. 2012. “Continent-scale genetic structure in a boreal forest migrant, the Blackpoll Warbler (Setophaga striata),” The Auk, 129: 467-478. Ralston, J., and J.J. Kirchman. 2013. “Predicted range shifts in North American boreal forest birds and the effect of climate change on genetic diversity in blackpoll warblers (Setophaga striata),” Conservation Genetics, 14: 543-555. Ralston, J., D.I. King, W.V. DeLuca, G.J. Niemi, M.J. Glennon, J.C. Scarl, J.D. Lambert. 2015. “Analysis of combined data sets yields trend estimates for vulnerable spruce-fir birds in northern United States,” Biological Conservation, 187: 270-278.

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Ross, Angelina M., and Glenn Johnson. 2012. “Recovery Plan for New York State Populations of Spruce Grouse” NYSDEC Report. Available at http://www.dec.ny.gov/docs/ wildlife_pdf/sprucegrouserecplan2013.pdf. Ruegg, K.C., R.J. Hijmans, and C. Moritz. 2006. “Climate change and the origin of the migratory pathways in the Swainson’s thrush, Catharus ustulatus,” Journal of Biogeography, 33: 1172-1182. Särkinen, T., R.T. Pennington, M. Lavin, M.F. Simon, and C.E. Hughes. 2012. “Evolutionary islands in the Andes: persistence and isolation explain high endemism in Andean dry tropical forests,” Journal of Biogeography, 39: 884-900. Steadman, D.W. 2006. Extinction and biogeography of tropical Pacific birds. Chicago: The University of Chicago Press. Tingley, M.W., W.B. Monahan, S.R. Beissinger, C. Moritz. 2009. “Birds track their Grinellian niche through a century of climate change,” Proceedings of the National Academy of Science, 106: 19637-19643. van Els, P., C. Cicero, and J. Klicka. 2012. “High latitudes and high genetic diversity: Phylogeography of a widespread boreal bird, the gray jay (Perisoreus canadensis),” Molecular Phylogenetics and Evolution, 63: 456-465. Wallace, A.R. 1881. Island Life. New York: Harper and Bros. Westemeier, R.L., J.D. Brawn, S.A. Simpson, T.L. Esker, R.W. Jansen, J.W. Walk, E.L. Kershner, J.L. Bouzat, and K.N. Paige. 1998. “Tracking the long-term decline and recovery of an island population,” Science, 282:1695–1698. Whitehead, D.R., and S.T. Jackson. 1990. “The regional vegetational history of the high peaks (Adirondack Mountains) New York,” New York State Museum Bulletin No. 478. Wiener, R.W., J.M. McLelland, Y.W. Isachsen, and L.M. Hall. 1984. “Stratigraphy and structural geology of the Adirondack Mountains, New York: Review and synthesis,” GSA Special Papers, 194:1-56. Zink, R.M. 1996. “Comparative phylogeography in North American birds,” Evolution, 50: 308-317. Zuckerburg, B., A.M. Woods, and W. Porter. 2009. “Poleward shifts in breeding bird distributions in New York State,” Global Change Biology, 15:1866–188.

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BIRDS OF THE ADIRONDACKS PHOTOGRAPHY BY LARRY MASTER

Male Blackpoll Warbler, Setophaga striata, singing.

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Male White-throated Sparrow, Zonotrichia albicollis, perching on a snag.

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Boreal Chickadee, Poecile hudsonicus, in winter.

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Male Blackburnian Warbler, Setophaga fusca, during migration.

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OCCUPANCY, DETECTION, AND CO-OCCURRENCE RATES OF AMERICAN BLACK AND MALLARD DUCKS IN THE SARANAC LAKES WILD FOREST AREA GARY A. J. MACY AND JACOB N. STRAUB 1 Center for Earth and Environmental Science, State University of New York-Plattsburgh, 101 Broad Street, 135 Hudson Hall, Plattsburgh, NY 12901, USA 1. Present Address: 175 East Fourth Street, Oswego, NY 13126, phone: 315.532.3333

ABSTRACT American black duck populations have steadily decreased across the northeastern United States prompting researchers to examine causes of decline including habitat loss, hybridization with mallards, and competitive exclusion by mallards. We designed a survey of lakes and wetlands of the Saranac Lakes Wild Forest and estimated occupancy and detection rates for each species. Given the predominantly forested landscape and the low density of humans, we predicted American black ducks would have greater occupancy rates than Mallards. Our results show each species was approximately equally likely to occur and to be detected, and there was no evidence that mallards excluded American black ducks from habitats. Mallards did show greater affinity for habitats with more humans present compared to American black ducks. Less than half of the lakes and wetlands we surveyed were occupied by either species indicating there is an abundance of unoccupied habitats that could have population-level ramifications for both species. KEYWORDS:

Adirondacks, Occupancy modeling, Waterfowl habitat, American black duck, Mallard

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INTRODUCTION Range expansion into the northeastern United States and release of farm-strain mallards (Anas platyrhynchos) has coincided with range wide population declines of American black ducks (Anas rubripes; hereafter black duck) (Ankney, Dennis, and Bailey 1987). Hypotheses regarding population trajectories between these species are complicated by their ability to hybridize and produce viable offspring (Heusmann 1974). Possible causes of black duck decline include habitat loss (Conroy et al. 1989), introgressive hybridization (Ankney et al. 1987), and competitive exclusion by mallards (Merendino and Ankney 1994; Merendino, Ankney, and Dennis 1993). However, few studies have specifically investigated black duck and mallard co-occupancy and interactions in the lakes, ponds, and streams of the Adirondacks with the exceptions of Brown and Parsons (1979), Dwyer and Baldassarre (1994), and Benson (1968). The Adirondack region represents a unique part of the Eastern Forest Boreal Transition zone. Mean annual temperatures are cooler than the surrounding lowlands of the Champlain and St. Lawrence valleys, and the landscape has less human development than the area surrounding it. From a botanical and climatological standpoint, the Adirondacks bear resemblance to boreal landscapes in Canada (Jenkins and Keal 2004). Much of the Adirondack Park is a mosaic of small ponds, lakes and wetlands with maturing forests throughout. Black duck populations appear to be stable in boreal forest habitats of Canada (Conroy, Miller, and Hines 2002), and, given similarities in habitat types, the Adirondacks may offer a refuge in which they can seek isolation from competitive mallards. Habitat isolation for the purpose of this study refers to an area or habitat type where black duck occupancy is greater than mallards in comparison to surrounding areas. Brown and Parsons (1979) and Benson (1968) counted relatively few mallards in their studies of the Adirondacks in the 1960s and 1970s. Less than 20 years later Dwyer and Baldassare (1994) found mallards and black ducks were mostly sympatric. These studies highlight the rapid expansion of mallards into the Adirondacks, but, excluding Dwyer and Baldassare (1994), they lack investigation into the forces driving mallard range expansion and black duck range contraction. Given these knowledge gaps we explored spatial relationships between the two species in the northwestern section of the Saranac Lakes Wild Forest Area (SLWFA). Specifically, we aim to test hypotheses regarding occupancy probability, for mallards and black ducks separately, relative to the degree of human influence (e.g., boat density, distance to campsites) and the configuration of the landscape (e.g., size of lake, amount of “edge” per lake). We also tested hypotheses regarding the probability of black ducks and mallards to co-occur in the SLWFA. Co-occurrence probabilities represent the degree to which each species ‘spatially separated themselves’ (MacKenzie et al. 2006) in the SLWFA. Given the known synanthropic qualities of mallards and the assumed shyness of black ducks (Ankney et al.

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1987), we expected mallard occupancy of lakes would be positively related to the degree of human activity and predicted an inverse relationship with black ducks. We also expected that mallard occupancy rates would be greater than black ducks on larger lakes and lakes with less edge to open water area and that co-occurrence would reflect spatial avoidance or exclusion between the two species.

METHODS Study Area The study area included a > 30,000 hectare mosaic of public land in the Adirondack Western Foothills ecozone (Will, Stumvoll, Gotie, and Smith 1982). Specifically, it consisted of the water bodies contained in a rectangle beginning on Floodwood road in the Town of Santa Clara, NY extending 4.8 km south and beginning on State Route 30 in the Town of Santa Clara extending 7.2 km west (Figure 1). The study area ranged from 478 to 481 m above sea level with a mean precipitation of about 90 cm per year and mean temperatures ranging from -11 oC in winter to 15 oC in summer (Kavanagh et al. 2014).

Study Design We surveyed approximately half of the lakes, ponds, and streams (hereafter sites) which are part of the northwestern section of the SLWFA. We constrained selected sites to those which could be accessed by canoe in a single day with portages of less than 1 km and total trip distances of less than 24 km. Thirty one discrete sites (Figure 1) were visited from one to six times on six separate canoe trips for a total of 94 site visits. One field researcher performed all surveys, therefore size of the study area and number of site visits was a reflection of very limited resources. Sites were visited as frequently as logistically possible while avoiding hazardous weather and still maintaining contiguous and unique routes through the area. Contiguous bodies of water were often subdivided into smaller sites that balanced areas of similar habitat type with easily identifiable features that aided accuracy on subsequent revisits. Therefore, a single researcher could visit discrete segments of larger water bodies and record presence or absence of our targeted species. Subdivision of contiguous water bodies into smaller sample sites was in the interest of achieving a finer resolution of habitat preferences and increasing the number of sampled sites. However, this approach could bias results because we are unaware to the extent the closed system assumption in occupancy modeling was violated (MacKenzie et al. 2006). This caveat is discussed later, however we suggest this method is sufficient for the accuracy of results needed in an observational study. Weather was mild for most site visits with winds < 10 mph, no precipitation, mean temperatures between 4.4 and 16.6 oC, and minimal cloud cover. Favorable weather and only one observer conducting surveys likely kept the effects of human error and environmental interference on detection probabilities consistent throughout site visits.

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Data Collection We surveyed all sites using Eagles Optics © 8 X 42 binoculars on six separate dates in 2013 (5/30, 6/5, 6/20, 8/12, 8/24, and 9/27). For each surveyed site, we recorded the presence or absence of mallards and black ducks after visually scanning the site for 30 minutes. We recorded latitude, longitude, and total counts of each species including ducklings, cloud cover, wind speed and direction, precipitation, number of boat/canoes present, a GPS track of the canoe path, and habitat type. We classified habitats as the general type of near shore terrain visible from the water level including descriptions of foliage and development. Due to the challenges of identifying black duck and mallard hybrids, each bird was classified as either species by the sum of traits according to discrete plumage between the two species (Carney 1992); therefore, we did not record any hybrids.

Geospatial Data Processing To gather information about potential explanatory landscape variables, we used ArcGIS 10.1. orthoimages of the study area, campsite locations, and hydrographic shapefiles (State 2014). These variables along with boat count data that we collected on each survey allowed us to derive covariates for maximum boats, patch size, length of patch edge, and mean distance to campsites. The campsites shapefile was missing campsites at Fish Creek Ponds campground and Rollins Pond campground, thus we digitized these from the orthoimages to establish a more representative human influence data layer. Maximum observed boats ranged from 0 to 24 at our sites, with the greatest amount in south Fish Creek and north Fish Creek Pond. Mean Euclidean distances to campsites ranged from 72 m to 454 m across sites. Patch sizes of the sites ranged from 54,000 m2 to 825,000 m2 with the largest sites occurring mostly on Rollins and Follensby Clear Pond. The ratio of open water to edge ranged from 1150 m to 4360 m. The output table from the data derived in ArcGIS was then opened in a spreadsheet program and used to calculate and standardize a covariate value following MacKenzie’s technique (2012).

Data Analysis Two-Species Model PRESENCE is a modeling program which uses detection histories applied to the principles and methods described by MacKenzie et al. (2002) to make estimates of site occupancy when detection probabilities are less than 1. We used a spreadsheet program to prepare data for import into PRESENCE, creating species specific detection histories for every visit date at all 31 sites. As described by MacKenzie et al. (2006), the presence of the target species was designated “1”, absence designated “0”, and missed site visits were input as “-”. The two-species model estimates five parameters which include: ψ = probability a site is occupied by a species, φ = the ratio of how likely a species is to co-occur at a site compared to what would be expected under an assumption of randomness, p = detection probability

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of a species in the absence of the other, r = detection probability of a species in the presence of the other and δ = the ratio of how likely a species is to be co-detected at a site compared to what would be expected under an assumption of randomness. For more details on these parameters see MacKenzie et al. (2006) and Bailey et al. (2009). We used a single season two-species model that used detection histories of mallards and black ducks to estimate the parameters mentioned above. Our two species model would not numerically converge when covariates were included (in the absence of covariates the model did converge) therefore we could not test whether covariates influenced any of the parameters above. We found this two-species model valuable because we were able to test our hypothesis regarding co-occurrence and detection probabilities of mallards and black ducks (although not relative to covariates). Eight competing models were ranked in order of greatest support by using Akaike’s Information Criteria (AIC) and we considered all models < 2 AIC units from the smallest value to be the most explanatory given our data. We also provided model weights (ωi ) which represent the relative weight of evidence for each model, and model-averaged parameter estimates were computed using all models < 2 AIC units from our best model (Burnham and Anderson 2002). All graphical depictions of model parameters were back-transformed to show the dependent variable on the original scale. Biological rationale for candidate model sets To test hypotheses regarding occupancy, detection, and co-occurrence relative to landscape configuration and human influence covariates, we built ecologically relevant candidate models and evaluated support for each through model selection (Burnham and Anderson 2002; Table 1). We addressed whether mallards and black ducks co-occurred independently or if there was evidence of competitive exclusion (i.e., ψ < 1). To address this hypothesis we fit models with and without the occupancy interaction factor (ψ). For sites occupied by both species, we explored whether the detection process was independent (i.e., λ ≈1) or whether detection of one species influenced the probability of detecting the congeneric species during a given survey (i.e., λ ≠ 1). To examine our detection probability assumptions we included models where r and p were constrained to be equal but varied between species denoted by p(S) and models were r and p were estimated separately. We explored whether the presence of mallards influenced the detection of black ducks (e.g., rjABDU < pjABDU) and vice versa (e.g., rjMALL < pjMALL). All combinations of these parameter structures were combined into eight competing models using a species-specific occupancy structure, ψ (S) (Table 1). Single-Species Models Because our initial goal was to examine how co-occurrence probabilities were influenced by site-specific covariates, and numerical convergence issues were preventing us from doing so with the two-species model, we ran separate single species models for mallard and black duck data. Although results of single-species models do not investigate spatial relationships between mallard and black ducks, they do examine species-specific occupancy relative to

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habitat covariates. Our habitat covariates served as surrogate variables for potentially explanatory responses by mallards and black ducks. For example, maximum boat counts and distance to campsites serve as proxies for a ‘disturbance,’ whereas as patch size and length of patch edge serve as ‘habitat configuration’ proxies. Single-species models included two parameters, ψ = probability a site is occupied and p = probability of detecting a species. Our base model consisted of only ψ and p with no covariates. To examine the influence of site-specific covariates on occupancy we applied the following variables to our base model: mean Euclidean distance to campsites (mdc), maximum boats (mp), patch area (pa), and ratio of open water to edge (o/e). We suspected the relationship of occupancy to these covariates might be non-linear; therefore, we built separate models with a second-order polynomial term for each covariate. In addition, we examined support for a global (i.e., saturated) model which was an additive model of all first-order covariates. Both singleseason models were assessed for goodness-of-fit by using a bootstrapping method on the global model to calculate c-hat (MacKenzie et al. 2006). C-hat for the mallard and black duck models were 1.53 and 4.52, respectively, which indicated overdispersion (MacKenzie et al. 2006). We adjusted for overdispersion by ranking all models using Quasi-Akaikes Information Criteria (QAIC), and we considered all models < 2 QAIC units from the smallest value (i.e., “best model”) to be the most explanatory given our data (Burnham and Anderson 2002).

RESULTS Data summary Among all 94 site visits, 57 adult black ducks and 127 adult mallards were observed. The naïve occupancy rate (i.e., rate of detecting a species not accounting for detection probability) was 0.258 for mallards and 0.290 for black ducks. Two-Species Model We considered two models (i.e., AIC < 2.0) to explain patterns in species-specific occupancy, co-occurrence, species-specific detection, and co-detection probabilities between mallards and black ducks (Table 2). Our best model (0.468 ωi ) contained five parameters and estimated a species specific occupancy probability (ψ; k = 2), co-occurrence (φ; k = 1), and probability of detecting each species (p; k =2). Our second-ranked model (ωi = 0.179) was identical to the best approximating model but it contained an additional parameter for estimating co-detection (λ). Model selection and associated parameter estimates indicate no evidence that mallards excluded black ducks spatially from sites in the SLWFA during summer 2013. The modelaveraged co-occurrence estimate (φ) of 2.021 (SE = 0.538) indicated strong evidence that mallard and black ducks tended to co-occur more often than would be expected under an assumption of randomness (MacKenzie, Bailey, and Nichols 2004; Table 5).

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Detection probabilities of both species were not influenced by the presence of the opposite species because both competing models had parameters where p = r. Detection probabilities were slightly greater and less variable for mallards (mean = 0.394, SE = 0.084) compared to black ducks (mean = 0.342, SE = 0.091). We found no strong or consistent interaction in the co-detection probability (λ). The top model fixed λ at 1, and our second model estimated it at 1.100 (SE = 0.286) indicating detection probabilities for each species were independent. Single Species Models Our best single-species model (Table 3) for black ducks was a model with no covariates and only parameters for occupancy and detection (ωi = 0.291). The second-ranked model (ωi = 0.116) was an additive model that linked variation in occupancy to mean Euclidean distance to campsites. We also considered a model (ωi = 0.112) where variation in occupancy was related to maximum boats observed at a site. None of the remaining models that we considered had greater support, including models that incorporated patch area, ratio of edge to open water, or any quadratic (i.e., non-linear) combinations of any covariate (Table 3). The model-averaged estimate of black duck occupancy was 0.493 while the model averaged estimate of detection was 0.319. The relationship for occupancy and Euclidean distance to campsites was non-linear while the relationship with maximum boats was linear and positive (Figures 2 and 3). The best single-species model (Table 4) for mallards was an additive model with parameters for occupancy and detection as well as linear covariate data for observed maximum boats (ωi = 0.475). The second-ranked model (ωi = 0.227) was also an additive model that linked variation in occupancy to the quadratic covariate for observed maximum boats. None of the remaining models that we considered had greater support, including models that incorporated patch area, ratio of edge to open water, mean distance to campsites, or any quadratic (i.e., non-linear) combinations of any covariate (Table 4). The model-averaged estimate of mallard duck occupancy was 0.417 while the model averaged estimate of detection was 0.314. Mallard occupancy increased in a non-linear fashion with increased observed boats (Figure 4).

DISCUSSION To our knowledge, this is the first study to estimate occupancy and detection probabilities for these two species in the Adirondack region. If mallards were displacing black ducks from habitats in this region, we would have expected to see greater occupancy rates for mallards compared to black ducks and less frequent co-occurrence of the two species, suggesting possible avoidance or competitive exclusion. This scenario would be consistent with predictions of Merendino et al. (1993) and Merendino and Ankney (1994), who suggest competition for habitat between mallards and black ducks is the cause of decline in black ducks. Our analyses provided no evidence of a negative association between occupancy of

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a site by the two species. Our co-occurrence estimate indicated that species tended to cooccur more often than would be expected if they were distributed randomly (MacKenzie et al. 2004). In other words, using our methodology there was little evidence that mallards competitively excluded black ducks (or vice versa) from sites in the SLWFA during summer 2013. As such, our findings are more consistent with Maisonneuve et al. (2006), who studied mallard and black duck interactions at the landscape scale in southern Quebec. They found mallard presence increased the odds of black duck presence by 200% and suggest that where habitat conditions are adequate those habitats are generally attractive to both species. Unlike Maisonneuve et al. (2006), our study was conducted at a much smaller spatial scale and in an area of the Adirondacks that has many lakes, beaver ponds, and associated wetlands that are surrounded by forests. Because a heavily forested landscape type is apparently preferred by black ducks (Maisonneuve et al. 2006, Morton, Kirkpatrick, Vaughan, and Stauffer 1989), we were somewhat surprised that black duck occupancy did not exceed mallards in this region. Instead, both species were approximately equally likely to occupy sites in the SLWFA. Although we found similar naĂŻve and estimated occupancy probabilities for mallards and black ducks across the SLWFA, we did see differences in how each species responded to site-specific landscape covariates. For instance, our best model for predicting black duck occupancy indicated that the covariates we measured had no strong or consistent influence on occupancy of a site. However, our second and third best models (which were statistically competitive) showed weak and somewhat conflicting evidence that black duck occupancy was a function of human-related activities. Black duck occupancy was greatest at sites where campsites where furthest away from site centers, while at the same time occupancy was positively related to observed boat traffic. Our finding that occupancy was less in areas with nearby campsites suggests black ducks are more secretive than mallards or are seeking seclusion during this time period; this is consistent with others findings (Ankney et al. 1987, Seymour and Titman 1978). However, we are curious and unsure why occupancy increased with observed boat traffic. A positive relationship with boat numbers may be the result of minimal disturbance (i.e., low hunting pressure) in this area, boaters feeding ducks, or it may also reflect hybrids with synanthropic qualities identified as black ducks. Regardless, we caution readers regarding inferences from these single-season black duck models because our most predictive model suggested covariates had no strong or consistent influence on occupancy of a site. In contrast to black ducks, mallards showed a clear and strong affinity for sites with greater human influence. The synanthropic qualities of mallards are well known, and this study supports that assessment observationally and numerically (Heusmann 1974). Our best model predicts that sites with greater than 15 boats on avearge will have mallard occupancy close to 100% while less than 10% occupancy is expected on sites with no boats.

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This suggests that mallards greatly preferred sites with more human activity. The strong preference may be the result of humans feeding ducks and minimal disturbance in state campgrounds and the surrounding landscape. The influence of humans and the presence of state campgrounds may also reduce the predation of nests and ducklings by birds of prey and other natural predators creating a refuge-like scenario. We emphasize some caveats associated with inferences about occupancy and detection models from program PRESENCE. First is the assumption that the occupancy state is â&#x20AC;&#x153;closedâ&#x20AC;? (MacKenzie et al. 2006). In our study, this implied that mallards and blacks ducks did not enter or leave sites during the time we monitored them. While there are some disjoint sites, many are connected via swimmable waterways and walkable corridors between water bodies. We are unsure of the extent these species moved among our sites, but we acknowledge that it likely occurred with some frequency. Violation of the closure assumption was likely reduced by the facts that both species were undergoing a wing feather molt and many should be flightless during the majority of the time we surveyed (Heitmeyer 1988, Leafloor and Ankney 1991). Second, hybrids were not accounted for but rather were identified as mallards or black ducks based on their plumage traits. This practice undoubtedly counted some hybrids as black ducks or mallards, which in turn may have falsely attributed species identifications. This inaccuracy may have had an effect on model estimates including occupancy and detection rates. Hybrids of these species have shown to retain attributes of one parent species and this may allow them to successfully access a wider range of habitat than the more limited other parent in terms of duckling success (Barnes and Nudds 1991). In our study, hybrids counted as black ducks may have been exhibiting synanthropic qualities of the mallard parent. Third, our inferences of co-occurrence (and thus competition) are based on observational patterns of species presence rather than directly observed interactions. Studies that focus on direct relationships such as behaviors of aggression, competitive exclusion, and mixed-species copulations can provide a different and deeper resolution to the degree of population-level competition between these two species. Additionally, our two-species models with covariate data applied did not produce usable results and instead indicated numerical instability, possibly due to the number of missed site visits. This prevented us from investigating human influence and landscape configuration on habitat preferences in the absence and presence of each species. Overall, less than half of the sites in the SLWFA were occupied by either species, even after accounting for failed detections. Furthermore, we never recorded presence of a single mallard or black duck at most sites. This finding surprised us because the SLWFA is a region of the Adirondacks with a great density of lakes and associated wetlands with diverse habitats. If this induction were applied to all lakes and wetlands in the Adirondacks then there is an abundance of potentially unoccupied habitats that could have population level ramifications for both species. Further research that attempts to identify features of the predominately occupied and unoccupied habitat areas is clearly needed.

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On a similar note, we were surprised by our relatively low detection rates (<40%) for each species. Given the caveat mentioned above, it is possible that some of our failed detections were a result of movement among or out of sites (i.e., a true absence). The other reasons for failed detections (i.e., false absences) include not encountering ducks because they were hiding or otherwise simply not encountered. Although we actively searched for ducks for ~30 minutes at each site per sampling occasion, we believe that “flush counts,” whereby we actively search dense vegetation and shoreline structure, should increase detection probability.

CONCLUSIONS Managers and researchers seeking to better understand interactions between black ducks, mallards, and hybrids should consider the effects of human influence in their management areas. We found densities of campsites and boat traffic are strongly related to the presence of mallards and the absence of black ducks. We observed several “feeding” events by humans in state campgrounds and mallards were often observed following canoes. Humans have likely aided the success of mallards in certain parts of the SLWFA. Curtailing these feeding events may help reduce the park-like conditions in which mallards succeed particularly well (Heusmann 1974). We found some regions of SLWFA where black ducks apparently seek isolation from boat traffic and campsites. These locations include the embayments on Follensby Clear Pond and the western shore and bays of Rollins Pond. The most distinctively plumaged black ducks were frequently observed in these ponds. Multiple breeding pairs of black ducks were observed nesting among downed trees along the western shore of Follensby Clear Pond. Future research in the SLWFA could focus on site-specific characteristics of these ponds to discover more about the preferences of black duck habitat choices. A more detailed study that includes hybrid counts would allow for more accurate estimates of occupancy and co-occurrence relative to covariate data. If introgressive hybridization with mallards is the main driving factor in the displacement/ reduction of black duck populations (Ankney et al. 1987), managers may need to consider methods to reduce the current population of mallards. A lack of habitat isolation in the SLWFA combined with the synanthropic qualities of mallards may have advanced introgressive hybridization in parts of our study area frequented by outdoor recreationists. Table 1 (see next page). Eight biological hypotheses tested between mallards and black ducks to estimate occupancy, co-occurence, detection, and co-detection probabilities from lakes and ponds in the SLWFA in summer 2013.

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CANDIDATE MODEL

OCCUPANCY CO-OCCURENCE PROBABILITY ( ψ) ( φ)

DETECTION PROBABILITY CO-DETECTION ( p, r )

ψA(S), φB(.), varies a spatial relationship p C(S) by species does exist*

varies by species, is the same regardless of presence of other species

detection of one species does not influence the probability of detecting the congeneric species

ψ(S), φ(.), p(S) varies a spatial relationship λD(.) by species does exist*

varies by species, is the same regardless of presence of other species

detection of one species does influence the probability of detecting the congeneric species

ψ(S), p(S) varies a spatial relationship rE(S) by species does not exist*

varies by species, is different and unique if the other species is present

detection of one species does not influence the probability of detecting the congeneric species

ψ(S), φ(.), p(S), varies a spatial relationship r(S) by species does exist*

varies by species, is different and unique if the other species is present

detection of one species does not influence the probability of detecting the congeneric species

ψ(S), p(S) varies a spatial relationship by species does not exist*

varies by species, is the same regardless of presence of other species

detection of one species does not influence the probability of detecting the congeneric species

ψ(S), p(S), varies a spatial relationship r(S), λ(.) by species does not exist*

varies by species, is the same regardless of presence of other species

detection of one species does not influence the probability of detecting the congeneric species

ψ(S), φ(.), p(S), varies a spatial relationship r(S), λ(.) by species does exist*

varies by species, is different and unique if the other species is present

detection of one species does not influence the probability of detecting the congeneric species

ψ(S), p(S), λ(.) varies a spatial relationship by species does not exist*

varies by species, is different and unique if the other species is present

detection of one species does not influence the probability of detecting the congeneric species

* tested if mallards and black ducks co-occurred independently or if there was evidence of competitive exclusion Table 2. Model selection statistics for two-species occupancy models fit to mallard and American black duck detection data from lake and ponds in the SLWFA, Adirondacks, New York in the summer 2013. The terms in parentheses represent the sources of variation in the model parameter; with “S” denoting species-specific differences, and “.” indicates a parameter set equal across species and survey times. Absence of φ or λ implies no interaction in occupancy or detection, respectively. Absence of r implies r = p. K indicates number of parameters in the model. MODELS

AIC

Ω i K

ψA (S), φB (.), p C (S)

168.7 0.00 0.46 5

ψ (S), φ(.), p(S) λ (.)

170.6 1.88 0.18 6

ψ (S), p(S), r (S)

171.3 2.59 0.13 6

ψ(S), φ(.), p(S), r (S)

172.7 3.97 0.06 7

ψ(S), p(S)

173.1 4.34 0.05 4

ψ(S), p(S), r(S) λ(.)

173.2 4.50 0.05 7

ψ(S), φ(.), p(S), r(S) λ(.)

174.6 5.84 0.03 8

ψ(S), φ(.), p(S), λ(.)

174.7 6.01 0.02 5

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Table 3: Model selection statistics for the top ten single-species models used to estimate occupancy (ψ) and detection (p) for American Black Ducks in the SLWFA study sites for summer 2013. Ranks are based on QAIC (Akaike’s information criteria adjusted for lack of model fit) and habitat covariates in parentheses were mean Euclidean distance to campsites (mdc), maximum boats (mb), patch area (pa), length of edge habitat—open water edge (e/o). A covariate with a superscript indicates a quadratic function while (.) denotes no covariate was used. K indicates number of parameters in the model. MODELS

QAIC

Ω i K

ψ(.), p(.)

21.8 0.00 0.29 2

ψ(mdc), p(.)

23.6 1.83 0.12 3

ψ(mb), p(.)

23.7 1.90 0.11 3

ψ(pa), p(.)

23.8 2.00 0.11 3

ψ(e/0), p(.)

23.8 2.00 0.11 3

ψ(mb + mb ), p(.)

24.5 2.70 0.08 4

ψ(pa + pa ), p(.)

24.9 3.10 0.06 4

ψ(mdc + mb), p(.)

25.5 3.75 0.5 4

ψ(mdc + mdc ), p(.)

25.6 3.78 0.04 4

ψ(e/o + e/02), p(.)

25.7 3.92 0.04 4

Table 4: Model selection statistics for the top ten single-species models used to estimate occupancy(ψ) and detection (p) for Mallard Ducks in the SLWFA study sites for summer 2013. Ranks are based on QAIC (Akaike’s information criteria adjusted for lack of model fit) and habitat covariates in parentheses were mean Euclidean distance to campsites (mdc), maximum boats (mb), patch area (pa), length of edge habitat—open water edge (e/o). A covariate with a superscript indicates a quadratic function while (.) denotes no covariate was used. K indicates number of parameters in the model. MODELS

QAIC

Ω i K

ψ(mb), p(.)

55.6 0.00 0.48 3

ψ(mb + mb ), p(.)

57.1 1.48 0.23 4

ψ(.), p(.)

59.2 3.57 0.08 2

ψ(mdc + mb + pa + e/o), p(.) 59.5 3.84 0.07 6 ψ(mdc + mdc2), p(.)

6.10 5.36 0.03 4

ψ(e/o), p(.)

61.0 5.38 0.03 3

ψ(mdc), p(.)

61.1 5.44 0.03 3

ψ(pa), p(.)

61.2 5.53 0.03 3

ψ(e/o + e/o ), p(.)

63.0 7.35 0.01 4

ψ(pa + pa ), p(.)

63.1 7.52 0.01 4

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Table 5: Model averaged parameter estimates of two-species occupational models for American Black and Mallard Ducks in the SLWFA study sites during summer 2013. The terms in parentheses represent the sources of variation in the model parameter; with “S” denoting species-specific differences, and “.” indicates a parameter set equal across species and survey times. Absence of φ or λ implies no interaction in occupancy or detection, respectively. Absence of r implies r = p. MODEL= ψA (S), φB (.), pC (S) PARAMETER

ESTIMATE

MODEL= ψ(S), φ(.), p(S) λD (.) SE

PARAMETER

ESTIMATE

MODEL AVERAGED PARAMETER

ESTIMATE

ψMALL 0.413 0.127 ψMALL 0.415 0.129 ψMALL 0.414 ψABDU 0.420 0.132 ψABDU

0.423 0.133 ψABDU

0.421

2.002 0.537 φ

2.021

2.029 0.538 φ

pMALL 0.394 0.084 pMALL 0.393 0.084 pMALL 0.394 pABDU 0.342 0.091 pABDU 0.342 0.091 pABDU 0.342 p EMALL 0.394 0.084 p EMALL 0.393 0.084 p EMALL 0.394 p EABDU 0.342 0.091 p EABDU 0.342 0.091 p EABDU 0.342

1.000

Fixed

1.100

0.286

1.028

A. probability of occupancy | B. probability of co-occurrence | C. probability of detecting species given other is not present D. probability of co-detection | E. probability of detecting species given both are present Figure 1: Saranac Lakes Wild Forest Area and study sites (filled-in light gray) where mallard and black ducks were observed during summer 2013.

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Figure 2: Relationships between estimated American black duck occupancy and mean Euclidean distance to campsites in the SLWFA during the summer of 2013. Relationship was modeled using top models in a singleseason model in Program PRESENCE.

Mean Euclidean Distance to Campsites (Meters)

Figure 3: Relationships between estimated American black duck occupancy and boats in the SLWFA during the summer of 2013. Relationship was modeled using top models in a single-season model in Program PRESENCE.

Peak Boats Observed

Figure 4: Relationships between estimated mallard duck occupancy and boats in the SLWFA during the summer of 2013. Relationship was modeled using top models in a single-season model in Program PRESENCE.

Peak Boats Observed

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L I TE R AT U R E C I T E D

Ankney, C.D., D.G. Dennis, and R.C. Bailey. 1987. “Increasing mallards, decreasing American black ducks: coincidence or cause and effect?” The Journal of Wildlife Management, 53(4), 523-529. Bailey, L.L., J.A. Reid, E.D. Forsman, and J.D. Nichols. 2009. “Modeling co-occurrence of northern spotted and barred owls: accounting for detection probability differences,” Biological Conservation, 142(12), 2983-2989. Barnes, G.G., and T.D. Nudds. 1991. “Salt tolerance in American black ducks, mallards, and their F1-hybrids,” The Auk, 108(1), 89-98. Benson, D. (1968). United States Situation. Paper presented at the Black Duck Evaluation, Managment and Research, Chestertown, MD. Brown, M.K., and G.R. Parsons. 1979. “Waterfowl production on beaver flowages in a part of northern New York,” New York Fish and Game Journal, 26(2), 142-153. Burnham, K.P., and D.R. Anderson. 2002. Model selection and multimodel inference: a practical information-theoretic approach. Fort Collins, Colorado: Springer. Carney, S.M. 1992. Species, age and sex identification of ducks using wing plumage. US Department of the Interior, US Fish and Wildlife Service Washington, DC Jamestown, ND. Conroy, M.J., G.G Barnes, R.W. Bethke, and T.D. Nudds. 1989. “Increasing mallards, decreasing American black ducks: No evidence for cause and effect: A comment,” The Journal of Wildlife Management, 53(4), 1065-1071. Conroy, M.J., M.W. Miller, and J.E. Hines. 2002. “Identification and synthetic modeling of factors affecting American black duck populations,” Wildlife Monographs (150), 1-64. Dwyer, C.P., and G.A. Baldassarre. 1994. “Habitat use by sympatric female mallards and American black ducks breeding in a forested environment,” Canadian Journal of Zoology, 72(9), 1538-1542. Heitmeyer, M.E. 1988. “Protein costs of the prebasic molt of female mallards,” The Condor, 90(1), 263-266. Heusmann, H.W. 1974. “Mallard-black duck relationships in the northeast,” Wildlife Society Bulletin, 2(4), 171-177. Jenkins, J. C., and A. Keal. 2004. The Adirondack atlas: a geographic portrait of the Adirondack Park. Syracuse, New York: Syracuse University Press. Kavanagh, K., L. Gratton, M. Davis, S. Buttrick, N. Zinger, T. Gray, et al. 2014. “Eastern forest-boreal transition.” Available at http://www.worldwildlife.org/ecoregions/na0406. VOLUME 20

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Leafloor, J.O., and C.D. Ankney. 1991. “Factors affecting wing molt chronology of female mallards,” Canadian Journal of Zoology, 69(4), 924-928. MacKenzie, D.I. 2012. PRESENCE User Manual. MacKenzie, D.I., L.L. Bailey, and J. Nichols. 2004. “Investigating species co-occurrence patterns when species are detected imperfectly,” Journal of Animal Ecology, 73(3), 546-555. MacKenzie, D.I., J.D. Nichols, G.B. Lachman, S. Droege, J. Andrew Royle, and C.A. Langtimm. 2002. “Estimating site occupancy rates when detection probabilities are less than one,” Ecology, 83(8), 2248-2255. MacKenzie, D.I., J.D. Nichols, J.A. Royle, K.H. Pollock, L.L. Bailey, and J.E. Hines. 2006. Occupancy estimation and modeling: inferring patterns and dynamics of species occurrence. San Diego, California, USA: Academic Press. Maisonneuve, C., L. Belanger, D. Bordage, B. Jobin, M. Grenier, J. Beaulieu, et al. 2006. “American black duck and mallard breeding distribution and habitat relationships along a forest-agriculture gradient in southern Quebec,” The Journal of Wildlife Management, 70(2), 450-459. Merendino, M.T., and C.D. Ankney. 1994. Habitat use by mallards and American black ducks breeding in central Ontario,” The Condor, 96(2), 411-421. Merendino, M.T., C.D. Ankney, and D.G. Dennis. 1993. “Increasing mallards, decreasing American black ducks: more evidence for cause and effect,” The Journal of Wildlife Management, 57(2), 199-208. Morton, J.M., R.L. Kirkpatrick, M.R. Vaughan, and F. Stauffer. 1989. “Habitat use and movements of American black ducks in winter,” The Journal of Wildlife Management, 53(2), 390-400. Seymour, N.R., and R.D. Titman. 1978. “Changes in activity patterns, agonistic behavior, and territoriality of black ducks (Anas rubripes) during the breeding season in a Nova Scotia tidal marsh,” Canadian Journal of Zoology, 56(8), 1773-1785. State, N.Y. 2014. NYGIS Clearinghouse. Accessed July, 2014 from https://gis.ny.gov. Will, G.B., R.D. Stumvoll, R.F. Gotie, and E.S. Smith. 1982. “The ecological zones of northern New York,” New York Fish and Game Journal, 29(1), 1-25.

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STATE OF THE BIRDS IN EXURBIA MICHALE J. GLENNON AND HEIDI E. KRETSER

Wildlife Conservation Society Adirondack Program, 132 Bloomingdale Avenue, Saranac Lake, NY 12983 ph: 518-891-8872, mglennon@wcs.org

ABSTRACT Low density rural sprawl, or exurban development, results in significant negative impacts on wildlife including birds. We describe the results of a decade of field studies to document the response of birds and other taxa to exurban development in the Park. We have investigated: the size of the ecological impact zone associated with exurban houses and roads in the Adirondacks, the characteristics of avian communities before and after residential construction, whether exurban development alters the health of individual birds, whether the ecological context of the development regulates the intensity of its impacts, and how individual land ethics and land use decisions, operating with a regional land use context, shape human impacts on biological communities. We briefly describe these studies and draw conclusions across them to provide insight into the state of the birds in the exurban Adirondacks. Broadly, we find that: the size of the impact resulting from exurban development can exceed its physical footprint significantly, changes in avian communities associated with exurban development do not appear to be driven solely by the associated road network, these changes can be very rapid and are consistent across some taxa and ecosystems, predation pressure may be a key mechanism, the attraction effect of exurban development may be stronger than the deterrent effect, and the most prevalent pattern of change is one of simplification of avian communities. Neotropical migrants may be a particularly sensitive group in the Adirondacks. KEYWORDS:

Adirondacks, bird community, biotic homogenization, exurban development

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INTRODUCTION Exurban development, or low-density rural sprawl, has significant consequences for wildlife habitat and populations (Reed et al. 2012). It is, at the same time, increasingly prevalent in the Adirondacks and beyond. Driven in part by proximity to natural amenities, exurban development consumes land and converts it to residential use at a rate 10 times that of urban and suburban development combined (Heimlich and Anderson 2001). Exurban development generally refers to development that occurs outside of the boundaries of incorporated cities and towns and is characterized by lot sizes in the range of 5-40 acres or more (Knight 1999, Theobald 2004). It is commonly believed that, because the matrix in which these dispersed homes are built remains in its original ecosystem type, the effects to wildlife from such a development pattern are minimal (Maestas et al. 2001). Recent work in the Adirondacks and elsewhere, however, suggests that significant changes to community structure, species behavior, and human-wildlife conflict patterns may occur as a result (Baron 2004, Casey et al. 2009, Glennon and Kretser 2013, Glennon et al. 2014, Hansen et al. 2005, Kretser et al. 2008, Odell and Knight 2001, Suarez-Rubio et al. 2011, SuarezRubio et al. 2013). We have been investigating the impacts of exurban development on birds and other wildlife in the Adirondacks since 2004. Using a variety of research approaches and techniques, we have executed a number of field projects in the Park to bring to bear evidence from our own local ecosystem into discussions about the future of the park and the important land-use management decisions that govern that future. We have asked a variety of questions in an attempt to address some of what we consider to be the most critical issues facing this landscape with respect to private land development and its consequences for wildlife communities. These questions include: (1) what is the size of the ecological impact zone associated with exurban development in the Adirondacks, (2) what is the size of the ecological impact zone associated with rural roads in the Adirondacks, (3) what are the characteristics of wildlife communities before and after residential construction, (4) does exurban development alter the health of individual animals in the Adirondacks, (5) does the ecological context of the development regulate the intensity of its impacts, and (6) how do individual land ethics and land use decisions, operating with a regional land use context, shape human impacts on biological communities? This paper constitutes an effort to provide an overview and basic description of each these studies and to draw conclusions that have resulted from this long-term research effort. In all of this work we have taken advantage of the wealth of species diversity provided by the Adirondack avifauna. Birds serve as ecological indicators more often than most taxa, both for their ease of sampling and the high numbers of speciesâ&#x20AC;&#x201D;and thus ecological functionsâ&#x20AC;&#x201D;often represented. This is the case in the Adirondacks as much as anywhere. Species richness of birds in the Park is an order of magnitude higher than that of other

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terrestrial vertebrates. The breeding birds of the Adirondacks span nearly 200 species distributed among 17 orders and 46 families. They make use of a wide variety of habitat types and, among them, represent a great diversity of breeding, feeding, and habitat guilds. As such, we can use birds as a powerful tool to investigate mechanisms of change within their communities. At the same time, the birds of the Adirondacks also constitute a range of commonness and rarity. Among them, more than 50 are considered species of greatest conservation need in New York by the Department of Environmental Conservation, and more than 50 have state rankings that indicate that they are limited to fewer than 100 occurrences statewide. While overlaps exist across these lists, they are not mutually exclusive. The work described here encompasses our efforts both to understand the impacts to Adirondack birds from this particular threatâ&#x20AC;&#x201D;that is, to describe the state of the birds in exurbiaâ&#x20AC;&#x201D;and to provide suggestions for how that impact might be mitigated, particularly for those species that may be sensitive or rare.

STUDY AREA All of our work has taken place in the Adirondack Park, and some of it has also occurred beyond the park. Within the Park, our studies have focused primarily in Essex County. The reason for this has been twofold: (1) we are located in Saranac Lake and the costs of working in more distant areas of the park have been prohibitive, (2) at the time we began our field studies, Essex County was the only one for which we had parcel data and boundaries for use in GIS. Being able to identify the owner is critical for any study making use of private lands. Essex County is 4,652 km2 (1,794 mi2) and has 39,000 residents. Most of Essex County is a heavily forested region in which natural openings are created primarily by wetlands and water bodies and is not heavily fragmented (Glennon et al. 2014). It is, however, the most highly populated county in the Park and the one in which numbers of building permits issued for new residential structures have been shown to exceed all other counties (Bauer 2001).

METHODS House Distance Effect This study was aimed at determining the ecological impact zone, or house distance effect associated with exurban development in the Adirondack Park. We borrowed methodology from a study that had asked the same question in Pitkin County, CO (Odell and Knight 2001), sampling birds at increasing distances from individual exurban homes. From among an initial selection of 136 parcels, we identified 30 willing landowners in Essex County within the towns of North Elba, Harrietstown, St. Armand, and Wilmington and visited each home twice during summer 2008. We used a standard point count methodology (Ralph et al. 1995) to sample the bird community at the forest/lawn edge, at 200 m into surrounding forest, and again at 400 m. We considered the 400 m (0.25 mi) distance to represent interior forest conditions. Point counts, the same method that has been used in all of our bird studies in the

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Adirondacks, constitute a 10 minute period of time in which all individuals of songbirds (Passeriformes) or woodpeckers (Piciformes) seen or heard are noted (this method is not appropriate for other types of birds). The sample period is divided into three time segments for the purpose of comparing with bird data from other programs, and, in addition to species, activity (i.e., singing, calling, or individual seen) and distance to observer (i.e., within or beyond 50 m) are noted. Data are also recorded for factors which may impact both bird activity and our ability to successfully detect birds including date, temperature, time of day, wind and sky conditions, and observer identity. All counts are conducted during the peak of breeding activity (approximately late May to early/mid-July for the Adirondacks), between 5:00 and 9:00 a.m., and are not conducted during rain or high wind. We repeated counts twice at each house and used occupancy modeling (MacKenzie et al. 2006) to examine differences in occurrence of human-sensitive, human-adapted, and neutral species at increasing distances from residential structures. This study is fully described in Glennon and Kretser (2013).

Road Distance Effect Because exurban development does not occur in the absence of roads, and because we wanted to determine whether observed impacts to bird species arose as a result of houses or the associated road network, we repeated the house distance effect methodology in the context of roads to determine the extent to which impacts from residential roads permeated into nearby intact forest. We chose a set of roads that represented a gradient of intensity of use and traffic levels and classified them into three broad categories of increasing impact based on a variety of characteristics including elevation, surface (paved/unpaved), canopy (open/closed), width, average speed, average annual daily traffic, and surroundings (nearby density of houses and roads, distance to water/wetland). We used the same point count method to sample birds at the road/forest edge, 200 m, and 400 m into interior woods to determine the potential impacts of both distance to road and road type on avian communities. We used occupancy modeling to examine changes in representation of birds within family groups among road types and at increasing distances from individual roads. This study is described more fully in Glennon and Kretser (2012a).

Before and After Effect The majority of studies that have looked at the impacts of residential development on wildlife have focused on existing development; opportunities to examine the impacts of development as it occurs are relatively rare and almost no studies have been conducted comparing pre- and post-development fauna in any ecosystem type (Hostetler et al. 2005). Albeit with a small sample size, we followed wildlife communities pre- and postdevelopment for two new homes constructed in the Adirondacks in 2009 with the goals of measuring the community of songbirds, small mammals, carnivores, amphibians, and plants before and after residential development and characterizing changes to these taxa brought

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about by development. In addition to point counts of songbird and woodpecker communities as described above, we also sampled small mammal communities with live trapping and track tube detections (Glennon et al. 2002), large mammals with infrared camera traps (Oâ&#x20AC;&#x2122;Connell et al. 2011), amphibians via timed searches, and plant communities via standard habitat sampling methods (Simon et al. 2001). We conducted surveys of the terrestrial vertebrate communities in 2008, prior to home construction, and again in 2010, one year post-construction, for both locations. At one of the sites we were also able to conduct sampling during the construction process in 2009. We also sampled at nearby control sites without development for both locations, but this design did not serve as a perfect before-aftercontrol-impact (BACI) experiment because controls were not added until 2009. We used an occupancy modeling approach to investigate changes to these ecological communities after construction, using a multi-season model to explore changes in the members of the species pool present at each site after construction (MacKenzie et al. 2006). We modeled changes to relative species richness after construction for bird, small mammal, and amphibian communities and investigated the likelihood of local colonization and extinction at each of these sites based on body size and family as well as population, reproductive, activity/ movement, habitat use/preference, and feeding/foraging characteristics. This study is described more fully in Glennon and Kretser (2012b).

Individual Health Effect The majority of our work has focused on changes to the structure of bird communities as a result of exurban development, but we are also interested in the potential effects of development on wildlife health at the individual level. Capitalizing on an existing concurrent study for which landowner permissions had been previously secured, we examined the impacts of exurban development on a forest songbird, the ovenbird (Seiurus aurocapilla) breeding in areas with and without exurban housing development. We captured 62 male ovenbirds in areas of exurban housing and nearby control sites using a playback recording and mist nests deployed in the vicinity of a singing male. All birds were captured between 6:00 a.m. and 12:30 p.m. EST in early June 2012 and 2013 during the peak of the breeding season for this species. We collected up to 150 ÎźL of blood via brachial venipuncture with a 26-gauge needle into heparinized capillary tubes immediately following capture. We also measured wing length and body mass and aged birds as second year or after second year based on plumage (Pyle 1997). We compared physiological condition of these birds using a variety of blood parameters including hematocrit volume and plasma triglyceride levels to compare energetic condition, plasma uric acid and total plasma protein levels to compare diet quality, and heterophil:lymphocyte ratios to compare chronic stress. Blood plasma samples were shipped to the Rochester Institute of Technology for analysis. Full details of this study are provided in Seewagen et al. (2015).

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Ecosystem Effect Hansen et al. (2005) stress that the effects of exurban development on biodiversity likely differ among ecosystem types and highlighted the need for research to derive generalities on the types of ecosystems that may be particularly vulnerable. We set out to address this question, in part, by comparing two contrasting ecosystemsâ&#x20AC;&#x201D;that of the northeast temperate forest of the Adirondack Park and the shrub-steppe system of the Greater Yellowstone Ecosystem in Montana. We hypothesized that impacts to bird communities would be greater in the relatively homogeneous, closed canopy Adirondack forest of northern New York State than they would be in the more naturally heterogeneous grasslands interspersed with trees and shrubs of Madison County, MT. We sampled bird communities via point counts distributed in three exurban subdivisions and paired control sites here in the Adirondacks and in Madison County, MT. All sampling was conducted by a single observer in each landscape, and all counts were conducted in June and early July 2007, with each site counted twice during the season. We examined birds within five functional groups expected to be responsive to exurban development including areasensitive, low-nesting, Neotropical migrant, microhabitat specialist, and edge specialist guilds, comparing relative abundance within subdivisions and control sites across these two regions. Full details of this study are provided in Glennon et al. (2015).

Bigger and Better Ecosystem Effect The study described above was executed as a single-season pilot study in 2007. Results of this small-scale study were intriguing enough that we have pursued the work on a much larger scale and have continued to investigate the broad question of the relative sensitivity of these two different ecosystem types to the same development pattern. In summers of 2012-2014, we again sampled bird communities in exurban subdivision and control sites in the Adirondack Park and Greater Yellowstone Ecosystem, in this instance working in seven subdivisions and matched control areas in Essex County, NY and Madison County, MT and working directly on the lands of 80-100 private landowners in each landscape. We sampled birds via point counts as previously described and also examined potential effects of exurban development on reproductive success of birds by locating and monitoring bird nests to document successful or unsuccessful nesting attempts. In addition to birds, we sampled mammal and plant communities, nighttime light disturbance, and acoustic characteristics in subdivisions and control sites. Plants were sampled via standard habitat sampling methods at all point count locations and around all nests after nesting was completed (Fletcher and Hutto 2008, Martin et al. 1997). Mammal communities were sampled via remotely-triggered trail cameras (Oâ&#x20AC;&#x2122;Connell et al. 2011) deployed along trails and other likely pathways of mammalian carnivore movement. Nighttime light disturbance was sampled via protocols developed in collaboration with the National Park

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Service Natural Sounds and Night Skies Division. Ambient sound characteristics in exurban subdivisions and control sites were sampled via autonomous recording units developed by Brown et al. (2013) and deployed for â&#x2030;Ľ10 days. Social research methods were used in concert with ecological survey methodologies to document and describe values, attitudes, behaviors, and practices of exurban homeowners in both landscapes. This was accomplished via standard 4-wave mail surveys and semi-structured interviews (Dillman 2000, Babbie 2010). Our aim with this recently-completed project is to delve much more deeply into the cross-site comparison of Adirondacksâ&#x20AC;&#x201D;Greater Yellowstone and to test, specifically, how individual land ethics and land use decisions, operating within a regional land-use context, shape human impacts on biological communities and how understanding this relationship can yield better management opportunities and potentially ecologically healthier landscapes. Our objectives are to (1) relate avian community structure and reproductive success at a local scale to landownersâ&#x20AC;&#x2122; land ethics and practices, (2) compare the relative roles of human disturbance versus alteration of habitat structure in controlling avian community structure and reproductive success in exurban subdivisions, (3) determine the effects of local versus landscape level habitat attributes on avian community structure and reproductive success in exurban environments, and (4) determine the extent to which the magnitude of the effects of exurban development on avian communities across diverse landscapes can be explained by the large scale connectivity and resilience of the encompassing regions.

RESULTS House Distance Effect In our examination of the ecological impact zone associated with exurban development in the Adirondacks, we found that bird communities were altered up to 200 m from exurban homes (Glennon and Kretser 2013). Occupancy rates for human-adapted and humansensitive species were different (36% higher and 26% lower, respectively) at points near homes versus those in surrounding forest (Figure 1). A 200 m distance effect translates to an area of 13 ha (31 acres) and suggests that the ecological impacts of development may far exceed its physical footprint. Our findings were very similar to those of a similar study in Pitkin County, CO (Odell and Knight 2001).

Road Distance Effect We found that the ecological impact zone associated with rural roads in the Adirondacks was similar in magnitude to that of the house distance effect (~200 m) but that different mechanisms are probably operating in these two circumstances (Glennon and Kretser 2012a). In this instance, we did not have a priori expectations of particular bird groups that would respond positively or negatively to roads and therefore analyzed birds within

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family groups. Also, because our selection of roads included a variety of characteristics and relative use levels, we investigated the impact of road type on avian communities. We found that, at the species level, the road type (hypothesized intensity of impact) more strongly influenced response of birds than did distance to road, with larger, paved, high-traffic roads having stronger impacts on adjacent bird community composition than smaller, unpaved, closed-canopy roads. When grouped into families, however, birds responded more strongly to the distance from the edge of the road than to the road type, suggesting that responses to roads are highly species specific. Similar to the house distance study, we identified a variety of responses of birds to roads, with sparrows attracted to road edges, and cardinal allies deterred by them. Most interestingly, however, a third group of birds (crows and jays) had high occupancy at road edges and in interior forest (400 m), but low occupancy at 200 m from the road (Figure 2). We do not have a simple biological explanation for this pattern.

Before and After Effect Our examination of pre- and post-development impacts on bird and other wildlife communities revealed patterns in the types of species that appeared most and least sensitive to residential development. For the most part, relative species richness increased after homes were constructed, but underlying community structure changed (Glennon and Kretser 2012b). For birds, probability of colonization after construction was most closely tied to migratory strategy, where local extinction probability was most closely related to clutch size, feeding guild, and migratory strategy (Figure 3). Longer distance migrants, Neotropical birds, were less likely to colonize and more likely to be lost from the sites, whereas yearround residents more likely to be found around the construction site. These patterns were mirrored in small mammal community changes as well, with bird and mammal species most likely to colonize and/or persist after residential construction being those who (1) nested in protected spaces (i.e., cavity, underground), (2) made use of numerous food sources (i.e., omnivores), andâ&#x20AC;&#x201D;within the context of these species groupsâ&#x20AC;&#x201D;those that (3) had larger body size and longer lifespan. Conversely, bird and small mammal species most likely to decrease in abundance and/or decline post-construction were those who (1) nested on the ground, (2) specialized in just one or two food sources, and (3) were of smaller body size and shorter lifespan. These findings suggest that significant changes to wildlife communities result from residential construction, even within very short time spans.

Individual Health Effect Among the physiological condition indices measured in our examination of individual health effects of exurban development on ovenbirds, we found that only hematocrit volume (HCT) differed for birds captured in exurban subdivisions and nearby control areas, with birds near houses exhibiting lower values (Seewagen et al. 2015). HCT is a widely reported

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hematological indicator of overall health in field studies of birds but is, at the same time, difficult to interpret and often discounted as a reliable index and not recommended as a sole indicator. The comparable values for all other blood parameters measured between subdivisions and control sites suggests that ovenbird food quality and availability were unaffected by exurban development in our study area and that exurban development does not significantly change chronic stressors faced by breeding male ovenbirds in these environments. We also found no difference in body mass, body size, or age ratio to indicate that habitats in either treatment type were in higher demand or more difficult to acquire. Effects of exurban development on this species may instead be mediated through attraction of synanthropic predators to these areas (Seewagen et al. 2015).

Ecosystem Effect In our study of the relative impacts of exurban development in two contrasting ecosystems, we hypothesized that birds in the Greater Yellowstone Ecosystemâ&#x20AC;&#x201D;with its greater degree of structural diversity and natural patchinessâ&#x20AC;&#x201D;would be less sensitive and demonstrate fewer community changes as a result of development, with a higher degree of change expected in the relatively continuous forest of the Adirondacks. We found no support for our hypothesis and instead found that, despite the strong differences between the two ecosystems, changes to bird communities were strikingly similar. For birds in the area-sensitive, low nesting, and Neotropical migrant functional groups, relative abundance was lower in subdivisions in both landscapes while edge species were more numerous in subdivisions (Glennon et al. 2014, Figure 4). The direction and magnitude of change in avian communities was similar in both regions for four of five guilds examined, suggesting that humans and their specific behaviors and activities in exurban regions may be more important than habitat structural change in shaping avian responses to development.

Bigger and Better Ecosystem Effect Findings from the prior pilot study to examine effects of exurban development in contrasting ecosystems (Glennon et al. 2015) were striking. Though they may simply be the result of small sample size, we were intrigued enough to pursue this work on a larger scale. The recent study, involving a total of ~180 landowners in both landscapes, and distributed over 33 study areas, has resulted in the collection of ~29,000 bird occurrence records, ~250 nest fate records, ~200,000 trail camera photos, ~19,800 hours of acoustic data, ~250 landowner surveys, and ~30 in-depth interviews with landowners and individuals in land management agencies. It is our hope that these data will enable us to investigate more fully the mechanisms of change in bird communities in exurban areas and to address how individual land ethics and land use decisions shape human impacts upon them.

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DISCUSSION AND CONCLUSIONS Though a growing literature has now begun to develop around the impacts to wildlife from exurban development (Reed et al. 2014), research addressing this form of land transformation still represents a small fraction of that which has been devoted to urbanization. When we began our research in the Adirondacks our aim was, in part, to provide information from field research executed in our own ecosystem. Most of what was known previously had come from studies conducted in the western United States and we were unsure of the degree to which such conclusions could apply in our eastern temperate forest system. Some of this work has since been published, and some has not, but we remain dedicated to our efforts to make use of the information to inform important land management decisions in the Adirondacks. We have regularly used these findings in discussions and comment letters to the Adirondack Park Agency, in working with local and regional planning authorities, in providing expert testimony, and in education and outreach efforts (Glennon 2012, Karasin et al. 2009, Karasin et al. 2013). We hope that they have been of use. We offer the following lessons learned from across the work we have conducted here on the impacts of exurban development and on the state of the birds in exurbia: 1. The size of the impact resulting from exurban development can exceed its physical footprint significantly Our work in the Adirondacks to examine the house distance effect for songbirds, together with findings from a similar study in Pitkin County, CO, and similar research focused on small mammals in the Adirondacks (Danks 2008) suggests thatâ&#x20AC;&#x201D;although the surrounding ecosystem remains in its original type and house and/or lawn size may be small, bird communities can be altered up to 200 m from exurban homes, translating to an impact area of 13 ha (31 acres). 2. The change in avian communities associated with exurban development does not appear to be driven solely by associated road network We examined the ecological impact zone resulting from rural roads in the Adirondacks as a means of disentangling the effects of home development itself from the fragmentation effect that comes along with the associated road network. Though we found that the size of the impact zone was similar in magnitude, patterns of change to bird communities were not, suggesting that changes to bird communities from exurban development arise from both houses and roads. 3. Changes to native bird communities can occur on very short timescales Our examination of characteristics of wildlife communities one year prior to and one year subsequent to construction of two exurban homes in the Adirondacks found measurable changes in avian (and mammalian) communities in this short time, suggesting that responses of bird communities can be very rapid.

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4. Predation pressure may be a key driver Our findings with respect to bird and mammal community changes in the context of residential home construction suggest that those species particularly vulnerable may be species that nest in less well-protected locations (e.g., ground-nesting vs cavity-nesting species). This pattern suggests that predation pressure may contribute to making particular types of species especially vulnerable. Dogs (Reed and Merenlender 2011, Silva-Rodriguez and Sieving 2012) and cats (Balogh et al. 2011, Gillies and Clout 2003) impact native wildlife, with cats increasingly found to be responsible for very large numbers of bird deaths annually (Lepczyk et al. 2003, Willson 2015). Zanette et al. (2011) found that, even in the absence of actual predators, the perception of predation risk alone can reduce the number of annual offspring produced by songbirds. 5. Attraction effect may be stronger than deterrent effect In several of our studies, we found the numerical response of species attracted to the features arising from exurban development is of greater magnitude than the decline observed for those species that appear to be sensitive. Omnivorous species such as corvids, for example, have consistently shown a greater numerical response (positive) to development than insectivores like warblers, which most commonly decline. This may be related to the provision of resources around exurban homes that are otherwise rare in the Adirondack landscape (e.g., openings, edges, novel food resources). This potential â&#x20AC;&#x153;oasis effectâ&#x20AC;? (Bock et al. 2008) offers both opportunity and challenge. Providing resources for these species can bring us into contact with birds we may not otherwise get to experience firsthand, but may also result in increased competition for rarer species who do not exploit exurban habitats as successfully. 6. Changes show some consistency across taxa and ecosystems In several of our studies, we have either observed changes in bird communities similar to those observed for other wildlife communities (Danks 2008, Odell and Knight 2001) or have ourselves noted similarities in patterns between bird community changes and those of other taxa. Similarly, we have noted similarities in patterns of change to avian communities in the Adirondacks and the very different ecosystem of Greater Yellowstone (Glennon et al. 2015). These findings provide us with increased confidence that we can reasonably predict the likely impacts to wildlife from development in the context of low density residential development. 7. The most prevalent pattern of change is one of simplification Across not only our work, but also that of researchers working with numerous taxa in many systems, we find that the same pattern appears again and again. In the context of exurban development here and elsewhere, species richness often increases, but is associated with a concomitant decrease in ecological specialization in the remaining community (Hansen

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et al. 2005). Humans tend to provide opportunities for certain types of species, often at the expense of other types of species. Among avian communities, in response to exurban development in the Adirondacks, the birds in exurbia tend to exhibit the following patterns: (1) sensitive species, e.g., black-throated blue warbler are often replaced by commensals or those that coexist with humans, e.g. blue jay, (2) insectivores decline with increasing omnivores, (3) migrants decline with increasing prevalence of resident birds, (4) forest obligates are replaced by habitat generalists, and, in general (5) rare species are replaced by those more common. Several of these more sensitive characteristics are often found among Neotropical migrant birds, a group which may be particularly sensitive to the negative impacts of exurban development. This phenomenon of a few winners and many losers in response to urbanization has been termed biotic homogenization (McKinney and Lockwood 1999). Its consequences for bird and other wildlife communities are not fully known but include simplification of food web structure and increased susceptibility of communities to species invasions (Olden et al. 2004). If we wish to maintain all of the bird diversity we enjoy in the Adirondacks, our challenge will be to maintain the opportunities that we can provide in the context of housing development for species that would not otherwise occur in the Adirondacks in high numbers, e.g. eastern blue birds, and that people can see and enjoy. However, at the same time we need to work to minimize the negative impacts that this development pattern creates for those more sensitive species experiencing population declines in New York State and those in the Northeast who breed more successfully in the contiguous forested lands characteristic of the Adirondacks, e.g. scarlet tanager. We hope that our work can help to inform land use management in the Adirondacks, so that the state of the birds in exurbia can be a net positive one.

ACKNOWLEDGEMENTS We are indebted to individual private landowners numbering in the hundreds who have graciously tolerated our presence on their lands, on multiple occasions, at impolite hours of the day and night, and with a variety of sampling techniques of relative degrees of invasiveness. We are eternally grateful to them. We also deeply appreciate the support of the former New York State Biodiversity Research Institute, Northeastern States Research Cooperative, National Science Foundation, Nuttall Ornithological Association, and Northern New York Audubon.

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Figure 1. Probability of occupancy at increasing distances from exurban homes for (a) human-adapted, and (b) human-sensitive species in the Adirondack Park, NY (Glennon and Kretser 2013).

Figure 2. Example of observed functional responses of occupancy probability for 3 bird families demonstrating positive (Emberizidae—sparrows), negative (Cardinalidae—cardinals, grosbeaks, and allies), and intermediate (Corvidae—crows and jays) response to increasing distance from rural exurban roads in the Adirondack Park, NY.

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Figure 3. Modeled effect of average clutch size on probability of local extinction (Îľ) of bird species following construction of 2 exurban homes in the Adirondack Park, NY (trend line added).

Figure 4. Model-averaged abundance (birds/point) of (a) area-sensitive, (b) low nesting, (c) Neotropical migrant, (d) edge-adapted, and (e) microhabitat specialist bird guilds in exurban subdivisions in Essex County, NY (grey squares) and Madison County, MT (black circles; Glennon et al. 2015).

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L I TE R AT U R E C I T E D

Babbie, E. 2010. The Practice of Social Research, 12th Edition. California: Wadsworth CENGAGE Learning. Balogh, A.L., T.B. Rider, and P.M. Marra. 2011. “Population demography of Gray Catbirds in the suburban matrix: sources, sinks, and domestic cats,” Journal of Ornithology, 152(3):717-726. Baron, D. 2004. Beast in the garden. New York: W.W. Norton. 288 pp. Bauer, P. 2001. Growth in the Adirondack Park: analysis of rates and patterns of development. Residents’ Committee to Protect the Adirondacks, North Creek, NY. 133 pp. Bock, C.E., Z.F. Jones, and J.H. Bock. 2008. “The oasis effect: response of birds to exurban development in a southwestern savanna,” Ecological Applications, 18(5):1093-1106. Brown, C.L., S.E. Reed, M.S. Dietz, and K.M. Fristrup. 2013. “Detection and classification of motor vehicle noise in a forested landscape,” Environmental Management, 52:1262-1270. Casey, J.M., M.E. Wilson, N. Hollingshead, and D.G. Haskell. 2009. “The effects of exurbanization on bird and macroinvertebrate communities in deciduous forests on the Cumberland Plateau, Tennessee,” International Journal of Ecology, 2009, article 539417, doi:10.1155/2009/539417. Danks, E.F.D. 2008. “Assessment of the impacts of residential development on mammal communities in the Adirondacks, New York,” Thesis, State University of New York College of Environmental Science and Forestry, Syracuse. 96 pp. Dillman, D.A. 2000. Mail and Internet Surveys: The Tailored Design Method, 2nd Edition. New York: John Wiley & Sons Inc. Fletcher, R.J., Jr., and R.L. Hutto. 2008. “Partitioning the multi-scale effects of human activity on the occurrence of riparian forest birds,” Landscape Ecology, 23:727-739. Gillies, C., and M. Clout. 2003. “The prey of domestic cats (Felis catus) in two suburbs of Aukland City, New Zealand,” Journal of the Zoological Society of London, 259:309-315. Glennon, M.J., W.F. Porter, and C.L. Demers. 2002. “An alternative field technique for estimating diversity of small mammal populations,” Journal of Mammalogy, 83(3):734-742. Glennon, M.J. 2012. “Best management practices for ecologically-sensitive land use planning and the protection of wildlife connectivity,” in Smith et al. (eds). Protecting wildlife connectivity through land use planning: Best management practices and the role of conservation development. Wildlife Conservation Society, Adirondack Program Technical Paper #4.

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Glennon, M.J., and H.E. Kretser. 2012. Impacts to wildlife from the ecological consequences of exurban development II: evaluating the ecological road effect zone. Final Report to the Northeastern States Research Cooperative. Available at http://nsrcforest.org/sites/default/files/uploads/ glennon10full.pdf. Glennon, M.J., and H.E. Kretser. 2012. Characteristics of faunal communities before and after residential development in the Adirondack Park. Final Report to the Northeastern States Research Cooperative. Available at http://nsrcforest.org/sites/default/files/uploads/glennon07full.pdf. Glennon, M.J., and H.E. Kretser. 2013. “Size of the ecological effect zone associated with exurban development in the Adirondack Park, N.Y.,” Landscape and Urban Planning, 112:10-17. Glennon, M.J., H.E. Kretser, and J.A. Hilty. 2015. “Identifying common patterns in diverse systems: effects of exurban development on birds of the Adirondack Park and the Greater Yellowstone Ecosystem, USA,” Environmental Management, 55:453—466. Hansen, A.J., R.L. Knight, J.M. Marzluff, S. Powell, K. Brown, P.H. Gude, and K. Jones. 2005. “Effects of exurban development on biodiversity: patterns, mechanisms, and research needs,” Ecological Applications, 15:1893–1905. Heimlich, R.E., and W.D. Anderson. 2001. Development at the urban fringe and beyond: impacts on agriculture and rural land. USDA Economic Research Service AER-803, Washington, DC. Hostetler, M., S. Duncan, and J. Paul. 2005. “Post-construction effects of an urban development on migrating, resident, and wintering birds,” Southeastern Naturalist, 4(3):421-434. Karasin, L.N., M.J. Glennon, and H.E. Kretser. 2009. Make room for wildlife: a resource for local planners and communities in the Adirondacks. Wildlife Conservation Society Adirondack Program. Available at http://www.wcsnorthamerica.org/AboutUs/Publications. Karasin, L.N., M.J. Glennon, and H.E. Kretser. 2013. Make room for wildlife: a resource for landowners in the Northeast. Wildlife Conservation Society Adirondack Program. Available at http://www.wcsnorthamerica.org/AboutUs/Publications. Knight, R.L. 1999. “Private lands: the neglected geography,” Conservation Biology, 13(2): 223-224. Kretser, H.E., P.J. Sullivan, and B.A. Knuth. 2008. “Housing density as an indicator of spatial patterns of reported human–wildlife interactions in Northern New York,” Landscape and Urban Planning, 84:282-292.

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Lepczyk, C.A., A.G. Mertig, and J. Liu. 2003. “Landowners and cat predation across ruralto-urban landscapes,” Biological Conservation, 115:191–201. MacKenzie, D.I., J.D. Nichols, J.A. Royle, K.H. Pollock, L.L. Bailey, and J.E. Hines. 2006. Occupancy estimation and modeling: Inferring patterns and dynamics of species occurrence. Burlington, MA: Elsevier. 324 pp. Maestas, J.D., R.L. Knight, and W.C. Gilgert. 2001. “Biodiversity and land use change in the American mountain west,” Geographical Review, 91:509–524. Martin, T.E., C. Paine, C.J. Conway, W.M. Hochachka, P. Allen, and W. Jenkins. 1997. BBIRD field protocol. Breeding Biology Research and Monitoring Database, Montana Cooperative Wildlife Research Unit, University of Montana, Missoula MT. 64 pp. McKinney, M.L., and L.L. Lockwood. 1999. “Biotic homogenization: a few winners replacing many losers in the next mass extinction,” Trends in Ecology and Evolution, 14:450–453. Odell, E.A., and R.L. Knight. 2001. “Songbird and medium-sized mammal communities associated with exurban development in Pitkin County, Colorado,” Conservation Biology, 15:1143-1150. O’Connell, A.F., J.D. Nichols, and K.U. Karanth. 2011. Camera traps in animal ecology: methods and analyses. Springer. 265 pp. Olden, J.D., N.L. Poff, M.R. Douglas, M.E. Douglas, and K.D. Fausch. 2004. “Ecological and evolutionary consequences of biotic homogenization,” Trends in Ecology and Evolution, 19 1):18-24. Pyle, P. 1997. Identification guide to North American birds. Pt 1. Bolinas, CA: Slate Creek. Ralph, C.J., S. Droege, and J.R. Sauer. 1995. Managing and monitoring birds using point counts: standards and applications. USDA Forest Service GTR-149. Reed, S.E., and A.M. Merenlender. 2011. “Effects of management of domestic dogs and recreation on carnivores in protected areas in northern California,” Conservation Biology, 25(3):504-513. Reed, S.E., H.E. Kretser, M.J. Glennon, L. Pejchar, and A. Merenlender. 2012. “Faunal biodiversity at the urban-rural interface: current knowledge, research priorities, and planning strategies.” Chapter 6 in D.N. Laband, B.G. Lockaby, and W.C. Zipperer, Eds. Urban-Rural Interfaces: Linking People and Nature. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Madison, WI. 332 pp.

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Reed, S.E., J.A. Hilty, and D.M. Theobald. 2014. “Guidelines and incentives for conservation development in local land-use regulations,” Conservation Biology, 28(1):258-268. Seewagen, C.L., M.J. Glennon, and S.B. Smith. 2015. “Does exurban housing development impact the physiological condition of forest-breeding songbirds? A case study of ovenbirds (Seiurus aurocapillus) in the largest protected area in the continental United States,” Physiological and Biochemical Zoology, 88(4): 416-424. Silva-Rodriguez, E.A., and K.E. Sieving. 2012. “Domestic dogs shape the landscape-scale distribution of a threatened forest ungulate,” Biological Conservation, 150:103-110. Simon, T.P., P.M. Stewart, and P.E. Rothrock. 2001. “Development of multimetric indices of biotic integrity for riverine and palustrine wetland plant communities along Southern Lake Michigan,” Aquatic Ecosystem Health and Management, 4:293-309. Suarez-Rubio, M., P. Leimgruber, and S.C. Renner. 2011. “Influence of exurban development on bird species richness and diversity,” Journal of Ornithology, 152:461-471. Suarez-Rubio, M., S. Wilson, P. Leimgruber, and T. Lookingbill. 2013. “Threshold responses of forest birds to landscape changes around exurban development,” PLOS ONE, 8(6):e67593. 1-11. Theobald, D. M. 2004. “Placing exurban land-use change in a human modification framework,” Frontiers in Ecology and the Environment, 2:139-144. Willson, Susan K. 2015. “The Birdbesafe® Cat Collar Cover: Why Cats in New York Need it More Than Australian Cats to Decrease Songbird Mortality,” Adirondack Journal of Environmental Studies, 20:101-107. Zanette, L.Y., A.F. White, M.C. Allen, and M. Clinchy. 2011. “Perceived predation risk reduces the number of offspring songbirds produce per year,” Science, 334:1398-1401.

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THE SARANAC LAKE CHRISTMAS BIRD COUNT: A 60-year Record of Winter Bird Populations in the Central Adirondacks LARRY MASTER

“ P RIOR TO THE TURN OF THE 20TH CENTURY, PEOPLE ENGAGED IN A HOLIDAY TRADITION KNOWN AS THE CHRISTMAS ‘SIDE HUNT’: THEY WOULD CHOOSE SIDES AND GO AFIELD WITH THEIR GUNS; WHOEVER BROUGHT IN THE BIGGEST PILE OF FEATHERED (AND FURRED) QUARRY WON. CONSERVATION WAS IN ITS BEGINNING STAGES AROUND IN THAT ERA, AND MANY OBSERVERS AND SCIENTISTS WERE BECOMING CONCERNED ABOUT DECLINING BIRD POPULATIONS. BEGINNING ON CHRISTMAS DAY 1900, ORNITHOLOGIST FRANK M. CHAPMAN, AN EARLY OFFICER IN THE THEN NASCENT AUDUBON SOCIETY, PROPOSED A NEW HOLIDAY TRADITION—A ‘CHRISTMAS BIRD CENSUS’—THAT WOULD COUNT BIRDS DURING THE HOLIDAYS RATHER THAN HUNT THEM”. —AUDUBON

OBJECTIVE To explore the past 40 years of data from an Adirondack Christmas Bird Count including relating selected environmental and other factors to bird observation patterns for more than two dozen species that overwinter in the High Peaks region.

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Every Christmas Bird Count takes place within an assigned territory—a 15-mile diameter circle in which the objective is to count as many birds as possible within one calendar day. Each circle has a compiler who picks the count date (sometime between December 14 and January 5) and assigns territories to the participants who will be counting the birds they see or hear. Birds seen or heard within three days of the selected the date for a particular count, but not observed on count day, are noted as occurring within the “count period” for that count that year. In 1947, Dr. Gordon M. Meade, a physician from Rochester who had a camp on Kiwassa Lake, was serving as the Associate Medical Director of the Trudeau Sanatorium in Saranac Lake. Meade was also a bird watcher, and in 1947 he helped organize and was elected first president of what became the New York Federation of Bird Clubs (now the New York State Ornithological Association). Also that year, Meade initiated the Saranac Lake Christmas Bird Count (SLCBC). Major and noteworthy habitat types in the count circle include mixed, boreal, and hardwood forests, lakes, streams, bogs, and fens. Elevations range from 445 to 1168 m, and the villages of Saranac Lake, Lake Placid, and Bloomingdale are within the circle (Figure 3). The first SLCBC took place on December 21, 1947. The two bird counters, including Meade, observed 63 individual birds representing 15 species. Since that inaugural count, the number of observers, bird species, and individual birds has steadily grown. For example, on December 30, 2012, 44 observers recorded 4,123 individuals of 51 species on the count (Figures 1 and 2). To date, 91 species have been observed on this CBC over its 59 years of recording birds (through January 2015), plus an additional five species have only been observed in the count period. All species’ scientific names are listed in Table 1 or in the text. Some of the more unusual (one time only) species observed include American Bittern (Botaurus lentiginosus; 1981), Golden Eagle (Aquila chrysaetos; 2011), King Rail (Rallus elegans; 1967), Northern Hawk Owl (Surnia ulula; 2000), Great Gray Owl (Strix nebulosa; 1983), Long-Eared Owl (Asio otus; 1998), Winter Wren (Troglodytes hiemalis; 1987), Ruby-crowned Kinglet (Regulus calendula; 2009), Gray Catbird (Dumetella carolinensis; 1975), Field Sparrow (Spizella pusilla; 1980), and Baltimore Oriole (Icterus galbula; 2005). The five species observed only during the count period but never observed on the day of the count were Northern Bobwhite (Colinus virginianus; 1996), Red-necked Grebe (Podiceps grisegena; 2000), Iceland Gull (Larus glaucoides; 1990), Northern Flicker (Colaptes auratus; 2008), and Hermit Thrush (Catharus guttatus; 1989). Consistency in counting birds on a bird count is important so that the results are comparable from year to year. In the early years of the SLCBC, the participants were not as rigorous as they perhaps could have been about staying within the count circle or perhaps their map of the count circle was not accurately drawn. Regardless of the reason,

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a handful of the more unusual birds in those early years (e.g., Eastern Meadowlark [Sturnella magna], American Kestrel [Falco sparverius], Lapland Longspur [Calcarius lapponicus]) were recorded in habitats that are somewhat outside the count circle (Normanâ&#x20AC;&#x2122;s Ridge, Saranac Lake Airport) where the open habitat frequently harbors birds not found elsewhere in the count circle. I adjusted the count circle in 2000 and 2001 by moving it approximately 1.2 miles NNE of its previous location to encompass an area just north of the count circle where folks, unbeknownst to me, had been counting birds for years in the 80s and 90s. The change did not affect any prior records as the southern edge of the count circle is roadless (Figure 3). Since I started compiling the count in 1975, for consistencyâ&#x20AC;&#x2122;s sake, we have always tried to hold the count near the end of the count period on the weekend nearest New Yearâ&#x20AC;&#x2122;s Day. Holding the count occasionally at the start of the count period in mid-December would likely yield more birds due to lingering fall migrants and gulls that linger before the lakes freeze but would yield results that are less comparable between years. Another benefit of holding the count late in the national count period is that winter finches (e.g., redpolls, crossbills, Purple Finches) often do not appear in significant numbers until late December or early January. The Christmas Bird Count (CBC) is an enormously useful source of data for researchers studying the ongoing status and ranges of bird populations across the Americas. Another citizen-science conducted census is the Breeding Bird Survey (BBS), which is done in the breeding season. Co-analyses of CBC and BBS data provide a combined metric by which scientists can assess how bird populations are doing and where they occur across the Americas. But users of these data must be aware of the limitations of the data and causes in the variation in the species and numbers of birds counted. Changes in the numbers of species and individuals counted can be affected by many variables and may not be purely representative of actual changes in species composition or population sizes in an area. More than in most CBC territories in North America, we can be certain that the number of species and particularly the number of individuals counted is a gross underestimate of the birds actually present in the Saranac Lake CBC territory. There are many lines of evidence for this, as follows. lthough more than 90 species have been recorded in the first 59 years of the SLCBC, A we know that in late December that in a typical year there are only approximately 53 species that one could reasonably expect to find. Yet, the highest count to date is 51 species and the average count is only 40 species.

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nly a tiny fraction of the count circle is actually visited by counters. If every road in the O circle were walked—listening for birds and “pishing” to attract birds during good weather in the morning when the birds are most active—such that all birds within 50 meters of the road were seen or heard, only 7% of the circle would be covered by birders (Figure 4). But most of the roads are driven rather than walked. (“Pishing” is the action of making a sound resembling the scolding note of a chickadee or titmouse. Birders and scientists use this technique to attract passerines (perching birds in the order Passeriformes), which approach the sound to assess the potential threat and potentially mob a predator (e.g., an owl). Making a squeaking sound also works similarly to attract some bird species.) Birds that are particularly under-sampled because of the lack of coverage of the 90% of the count circle without roads or trails are those species that live in the forest including owls, chickadees, nuthatches, kinglets, Brown Creepers (Certhia americana), woodpeckers, and, especially during conifer mast crop years, some of the winter finches. For example, the actual number of Black-capped Chickadees (Poecile atricapillus) residing in the count circle might be conservatively estimated to be 10-20 times the number actually counted, or well over 10,000 individuals. Even when the roads are walked, most birds are likely missed due to the birds not vocalizing or not responding to pishing, poor hearing or experience in identification on the part of observers, or observers not pishing. Observers may also be concentrating on birds in the bushes and trees and miss birds flying silently high overhead (e.g., raptors, Snow Geese [Chen caerulescens]). T he weather is often not conducive for hearing or seeing birds. A windy or rainy day or a day with heavy snow will significantly reduce the variety and especially the number of birds seen or heard, compared to walking the same area on a sunny morning with no wind. I n alternate years with a poor wild food crop, the birds are concentrated in areas with bird feeders. For this reason, we have always tried to ensure that the villages and areas with known bird feeders as well as particular uncommon habitats (e.g., open fields, open water on lakes and rivers, large expanses of accessible boreal bog habitat) are as well and consistently covered as possible. But in years with a good crop of conifer mast (spruce [Picea spp.], fir [Abies spp.], eastern hemlock [Tsuga canadensis], pine [Pinus], and/or birch [Betula spp.]), the birds are much more dispersed and are under-counted. There are likely multiple factors at play that affect the numbers of birds counted on any particular count. For example, on January 2, 2010 (the 2009 count), the numbers of species recorded was the lowest in two decades; without a near record number of American Goldfinches (932), it would have been the lowest recorded number of individual birds in 25 years. One might reasonably hypothesize that the low recorded numbers that day could be due to some combination of factors such as snowy cold

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weather on count day, the bitter cold temperatures in the weeks preceding the count, the near absence of conifer mast, the absence of a flight year for redpolls, and/or poor reproductive success for local resident species due to the cold and rainy summer weather the previous year. A useful research project would be to tease out the relative importance of these or other contributing factors, which is an analysis requiring more data than are currently available. Another well-documented variable affecting the results is observer effort, and so count participants record their effort in miles and hours walked, driven, kayaked, skied, etc. Count participants also record the number of hours spent birding with other participants, a metric known as â&#x20AC;&#x153;party-hours.â&#x20AC;? Although the number of observers and the number of party-hours is highly correlated (r2 = 0.77), party-hours provides a better metric of observer effort and count results are often calibrated based on party-hours in the field. Statistical methods have been developed to account for variation in effort (e.g., Link and Sauer 1999). In the most recent four years, count participants have put in more than 100 party-hours, while party-hours from 1976 through 2010 ranged from 40 to 87 (without taking into account the three extremes at each end). Yet, because other factors (wild food crop, weather) are so influential in determining the birds seen on any given count, observer effort explains only 62% of the variation in number of species and 45% of the variation in the total number of individual birds seen. For some birds such as the permanent resident Black-capped Chickadee, there is a fair correlation (r2 = 0.63) between observer effort (party-hours) and numbers of individuals observed. For many other species, however, the correlation is weak (e.g., American Goldfinch, r2 = 0.14) as other factors, particularly the wild seed crop, are more critical (Figure 5). The remainder of this paper will discuss questions that one might ask of the SLCBC data. Despite limitations in the data discussed above, there are conclusions that one can reasonably make regarding changes in the species recorded as well as trends and patterns in their occurrence over the years. The first two questions below will examine data over the entire period that the count has been conducted, from 1947-1954, 1957, 1959-1968, and 19752014. Because of some differences in the way the count was conducted prior to my tenure as compiler (beginning in 1975), which are reflected in the data (Figures 1 and 5), the third question posed will just examine the past 40 years of data.

HAVE THE SPECIES PRESENT ON THE SLCBC CHANGED OVER THE YEARS? During the first 21 years of the SLCBC (19 counts spanning the years 1947-1968), several birds that were never or only rarely reported in this timeframe became much more regular in later years.

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There are a number of likely explanations, depending on the species, for these increases in species occurrence over time. Canada Goose, mergansers, Great Blue Heron, and gulls. The degree of open water was not recorded on earlier counts (1947-1968); it seems probable that there was less open water in early winter than in more recent years, based on documented changes in ice-in dates on Adirondack lakes (Beier et al. 2012, Stager et al. 2009). It is also likely that no one boated the Saranac River or surveyed the Moose Lodge boathouse “bubblers” on Lake Placid before dawn where the mergansers have been found in recent years. But Canada Goose populations have also increased dramatically over the years in New York and across much of the country ( Johnsgard and Shane 2009). The New York breeding population alone increased from about 5,000 pairs to 90,000 pairs in 2005 (McGowan and Corwin 2008). Wild Turkey. Turkeys were extirpated from New York State as well as all of New England by the start of the 20th Century. However, releases of wild-caught birds from other states were successful in reestablishing turkeys throughout New York State, even in the central Adirondacks where it had been postulated that they could not establish a population (DeGraff 1973). Wild Turkeys first appeared on the 1994 SLCBC and by 2002 more turkeys than Ruffed Grouse (Bonasa umbellus) were being counted. On a typical count in recent years, 25-30 turkeys were counted (Figure 6). Bald Eagle. Due to persecution by humans and deleterious effects on their reproduction by the pesticide DDT, bald eagles were functionally extirpated as a breeding species from New York by the mid-20th century (NYS DEC 2015). The NYS Department of Environmental Conservation mounted an aggressive restoration effort in the mid-70s that was very successful. Eagles were first counted on the 1987 SLCBC and one to four eagles are now observed every year, mostly along the open waters of the Saranac River (in late December). Accipiters (forest-dwelling hawks). Northern Goshawks (Accipiter gentilis) staged a resurgence starting in the 1950s in New York as the forests in which they nest matured (Crocoll 2008), and perhaps the increase in their numbers accounts for the increase of Northern Goshawk sightings on more recent counts. Cooper’s and Sharp-Shinned Hawks (Accipiter spp.) are mostly found in winter near bird feeders. There are unquestionably many more people feeding birds in recent years, which explains why the number of bird species that are drawn to feeders (goldfinches, Purple Finches, redpolls) have dramatically increased since the earlier counts. Buteos (hawks with broad wings). Both Red-Tailed Hawks (Buteo jamaicensis) and Rough-Legged Hawks (Buteo lagopus) were not observed on the SLCBC until the mid-80s. This change may or may not relate to a general pattern of shifting centers of early winter

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distribution reported for Rough-Legged hawks and other birds by Niven et al. (2009). Red-Tailed Hawk populations have also been increasing over the past 50 years (Johnsgard and Shane 2009). Mourning Dove, Tufted Titmouse, Carolina Wren, Northern Cardinal, Common Grackle. The first mourning dove was recorded in 1976, the first titmouse in 1979, and the first Carolina Wren in 1986. Cardinals and grackles were rarely recorded prior to the 1970s and are now expected every year, with as many as 26 cardinals and 10 grackles reported on a single count. These increases can be attributed to the northward expansion of the ranges of these species correlated with warmer January weather experienced in the contiguous 48 states over the past 40 years (Niven et al. 2009, Zuckerberg et al. 2009), likely aided by bird feeders allowing overwinter survival in the central Adirondacks. Barred Owls. Barred Owls were not recorded in the 19 years of the count prior to 1975. Since 1975, they have been recorded on 23 of 40 counts, with a high count of 8 in 2013. There is some evidence that Barred Owls have become more common over the past 60 years (McGowan and Corwin 2008), but there is also reason to believe that Barred Owls were overlooked in the earlier counts. Ninety percent of the Barred Owls counted have been individuals heard at night, most of them lured into responding by playback or imitation of their callsâ&#x20AC;&#x201D;a technique that was likely not done in the early years of the count. Black-backed Woodpecker and Gray Jay. Habitat for these species is easily accessible only in a few limited spots in the count territory (primarily Chubb River Swamp and Bloomingdale Bog/Bigelow Road areas), and these areas may not have been adequately surveyed on the earlier counts, particularly prior to 1961. Occurring in the same coniferous habitat are Boreal Chickadees (Poecile hudsonicus), which were missed in counts prior to the 60s. Gray Jays have increased in abundance locally in these areas as double digit numbers of this species are now routine but were unrecorded prior to 1997. Further, prior to the 1980s they were only observed at two (suet and breadcrumb) feeders that may have been overlooked or may not have existed prior to 1967. American Three-Toed Woodpecker. Six individuals of this species were recorded on seven counts from 1978-1985, but only one individual has been recorded once since then (in 1998). The two New York Breeding Bird Atlases (Andrle and Carroll 1988, McGowan and Corwin 2008) and earlier reports summarized by Bull (1974) are indicative of a significant decline for this species in New York, where it is largely confined to the Adirondacks. The rarity of this species hinders anything other than idle speculation as to the reason(s) for a decline, if any, on the SLCBC. Common Raven. Forest clearing and persecution nearly eliminated this species from New York. The population began to naturally recover in the 1970s, and the first raven appeared on the SLCBC in 1968. The numbers of ravens in annual SLCBC counts hit double digits in 1985 and reached a high to date of 67 birds in 2008 (Figure 6).

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American Robin. First recorded in 1983, robins have been recorded on one-third of counts since then with a high of 46 individuals in 1998. Their winter range may be expanding northward as the climate warms (Niven et al 2009), aided by ornamental crab apple trees whose fruit lingers into the winter months, if not stripped bare by waxwings and robins in fall migration. Bohemian Waxwings. This species winters every year in the St. Lawrence and Champlain Valleys. It is only occasionally reported on the SLCBC, having usually passed through the count territory by early December and consuming most of the crab apples and available wild fruits en route. House Finch. This western North American species was released on Long Island in 1940 and spread over the eastern U.S. over the next 50 years. House Finches first appeared on the SLCBC in 1985, then reached a peak of 72 individuals in 1994, and were last recorded on the count in 2004 (Figure 7). Their rapid decline after 1994 on the SLCBC was likely caused by the epidemic of House Finch eye disease caused by the bacterium Mycoplasma gallisepticum, which spread through the eastern range of the House Finch in the mid-90s (Driscoll 2008). Hoary Redpoll. This species was likely overlooked among small flocks of Common Redpolls (Acanthis flammea) prior to the 1990s when significant numbers of common redpolls began to be counted at nyjer (or niger, sometimes called thistle) feeders on count day. Typically one out of every 200 redpolls will be an identifiable hoary redpoll, but the actual percentage is likely closer to one percent due to the difficulties in identification of this species of questionable taxonomic validity (Mason and Taylor 2015).

HAVE THE NUMBERS OF INDIVIDUAL SPECIES THAT HAVE BEEN PRESENT SINCE THE COUNT STARTED CHANGED SIGNIFICANTLY OVER THE ENTIRE 67 YEAR PERIOD OF THE COUNT? American Crow (Corvus brachyrhynchos). Before 1982, no more than 30 crows were counted in any given year on the count and fewer than six crows were counted most years. Then their numbers increased rapidly, peaking in 1991 with 355 crows; more than 100 crows have been recorded in 19 of the past 21 counts (Figure 6). This increase corresponds to an accelerating long-term increase in BBS data for New York in the 1980s. The data, however, are too variable from year to year to say whether there was decline in the early part of this century when crow numbers elsewhere declined due to the 1999 outbreak of West Nile Virusâ&#x20AC;&#x201D;a virus commonly spread by infected mosquitoesÂ that affects humans and birds, especially crows and jays (CDC 2015).

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Evening Grosbeak (Coccothraustes vespertinus). Evening Grosbeaks were a species of the central and western U.S. and Canada until the mid-1940s when they moved eastward and later began to breed in New York (Young 2008). In three of the first seven years of the SLCBC, Evening Grosbeaks comprised a quarter of the birds counted. Numbers then declined somewhat but peaked again in the late 70s and early 80s when they comprised more than half of the birds in two counts and more than 29% of the birds counted on five other counts. Since the late 1990s Evening Grosbeaks have declined, consistent with reports from other CBCs in the Northeast. In the last two years no Evening Grosbeaks have been recorded, which is the first time that none have been recorded since 1947 (Figure 8). Breeding of this species in New York increased between the 1980-85 New York Breeding Bird Atlas (Andrle and Carroll 1968) and the 2000-05 Atlas (McGowan and Corwin 2008). It is unclear whether these changes relate to major outbreaks in the eastern spruce budworm (Choristoneura fumiferana) in New York in 1945-55 and again in 1968-88 (Young 1988), but these two periods correspond with high SLCBC counts for this species. Birders and scientists have long been aware that populations of Evening Grosbeaks and several warbler species increase during outbreaks of spruce budworms (Choristoneura spp.), a preferred food of these species when nesting and feeding their young (e.g., Bolgiano 2004).

ARE THERE OBVIOUS PATTERNS IN SPECIES OCCURRENCE RELATED TO CHANGES IN FOOD SUPPLY? A cursory examination of Figure 1 reveals significant annual variation in the number of individual birds recorded, but the data for individual species are striking (Figures 9-11). Some years there may be hundreds or thousands of individuals of a particular “winter finch” species (Purple Finch, Pine Siskin, White-winged Crossbill, American Goldfinch, Common Redpoll, and Pine Grosbeak), and in other years there are none or almost none. Numbers of two short-distance migrating passerines—Blue Jay and Red-Breasted Nuthatch—show similar degrees of variation involving hundreds of individuals. The variation in the numbers of winter finches observed is not random. The peak counts for one or more of the conifer seed-eating birds (Red-breasted Nuthatch, White-winged Crossbill, Pine Siskin) occurred consistently on the odd-numbered years from 1984-1991, on the even-numbered years from 1994-2008, and on the odd-numbered years again starting in 2009 (Figure 9). The peak counts for American Goldfinches follow the same pattern of evennumbered years from 1994-2008 and odd-numbered years starting in 2009. However, the largest count recorded for goldfinches occurred in 2013, a year with almost no other finches. Prior to 1994, the peaks for goldfinch numbers were on the even-numbered years going back to 1975 (Figure 10). Peaks for redpolls have been on odd-numbered years from 1987-2007 and on the even-numbered years starting in 2010—years when the other winter finches were not observed or were observed in low numbers (Figure 10).

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It is well known that winter finch numbers are tied to the abundance of their food (Pittaway 2014). Since 1975 the wild food crop has been recorded with other data for the Saranac Lake CBC. What has been recorded is my qualitative judgment as to whether the autumn spruce cone mast is excellent, good, fair, or poor. These conifers tend to mast synchronously not only across species but also across large geographic areas (e.g., the Adirondacks and adjacent areas in Canada and New England) (Jensen et al. 2012). For purposes of this paper “good” and “fair” mast cone crops have been combined. In general, excellent or good to fair cone crops occur every other year, and in 17 of the past 40 years (42%) the conifer mast has been rated “poor.” A comparison of the mast crop with numbers of Red-Breasted Nuthatches, White-Winged Crossbills, Pine Siskins, Purple Finches, and Blue Jays shows that all of the top five counts were in years with excellent or good/fair mast cone crops, and the average number of birds counted in a poor year was as much as an order of magnitude less than the count in a year with an excellent or a good to fair mast crop (Figures 9 and 11; Table 2). Although only three of these species (crossbill, siskin, nuthatch) are dependent on conifer seeds in the Adirondacks in winter (Blue Jays eat acorns, beechnuts, and other “hard mast”, while Purple Finches eat “soft mast” such as fruits as well as seeds and buds), the numbers of all five species are linked to conifer mast. This is likely because of the synchrony between conifer species and other fruiting plants in the Adirondacks. A 24-year study at Huntington Wildlife Forest found that most of the 50 fruiting herbs, shrubs, and trees are on a two year cycle that is congruous among them, including conifers (Jensen et al. 2012, S. McNulty email correspondence). That cycle is congruous with the conifer mast production observed on the SLCBC and with beech, oak (Quercus spp.), and maple mast in central Ontario, Canada (Bowman et al. 2008). There is also considerable variation between species in the years of their highest count. For example, 1976 was the best year for both Purple Finch (1,033 individuals) and Red-breasted Nuthatch (311 individuals), but this was not a “top five” year for any of the three other species. The best year for White-Winged Crossbill (1,146 individuals) was 1989, but this was only a “top five” year for Pine Siskin and no other species. The best two years for Pine Siskin (2,021 individuals in 2008 and 1,903 in 1987) were not “top five” years for any of the other species (Figures 9 and 11). There are several reasons for these differences. Pine Siskins depend on hemlock mast and hemlock mast crops are usually but not always synchronous with spruce mast, on which the other conifer mast-eating species depend. Also, food supplies to the north in Canada play a major role in which species occur in the Adirondacks in winter, although conifer and other mast in the Adirondacks tend to be similar to mast crops in adjacent parts of Canada (Jensen et al. 2012). The numbers of American Goldfinch, which eat seeds of grasses, alder, birch, and cedar, also tend to peak every other year. Counts of more than 100 goldfinches were synchronous with counts of more than 100 Purple Finches, crossbills, and siskins in 12 of 19 years (Figures 9-11). This partially synchronous pattern may be a result of simultaneous biannual

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variation in the availability in Canada and in the Adirondacks of the wild foods that they consume in the winter. The Moran effect (correlated environmental patterns) operates in small mammal populations synchronized to wild food crops in Ontario and other systems (Bowman et al. 2008) and is potentially driving synchrony among some Adirondack winter bird populations. However, the Moran effect is not sufficient to explain synchronous mast fruiting events of boreal trees (Koenig and Knops 2000). Both the reasons for mast fruiting (e.g., predator satiation, increased seed production) and the mechanisms of synchrony remain open areas of research. Pine Grosbeak numbers irrupt southward in winter when mountain ash (Sorbus americana) berry crops are poor in the boreal forest as these birds are ash seed specialists. Although somewhat irregular in their appearance on the SLCBC (Figure 10), Pine Grosbeaks tend to show an every-other-year pattern of abundance tied to annual variation in mountain ash seeds in Canada. The mountain ash berry crop in the Adirondacks must be synchronous into Canada where our Pine Grosbeaks originate. Jensen et al. (2012), working at a forested site in the southern High Peaks, found mountain ash produced a berry crop in most even autumns from 1990-2010, just the years when Pine Grosbeaks did not irrupt southward and appear on the SLCBC (Figure 10). Prior to 1980, the largest count of redpolls was 31 individuals. Since 1980, redpoll numbers are typically in the hundreds, and as many as 1,535 individuals have been recorded. Redpolls have quite reliably appeared every other year since 1987, first on the odd numbered years from 1987 through 2007 and then on the even numbered years starting in 2008 through 2014 (Figure 10). Low redpoll counts in some flight years are due to the fact that the birds often do not appear in numbers until after the SLCBC period. This was the situation in the winter of 2014-15 when only 26 redpolls were found on count day. Then, starting in February, many hundreds were seen daily in the count territory. The movement of the birds is caused by the biannual failure of birch (and possibly alder) seed crops in the boreal forest. (For more information on irruptive boreal mast-consuming birds, see Ron Pittawayâ&#x20AC;&#x2122;s past winter finch forecasts for southern Ontario (Neily 2011) and his current forecast for Ontario and adjacent states (Pittaway 2015).

WINTER BIRDS AND FEEDERS A significant percentage of birds counted on the SLCBC are observed at or near bird feeders. On the 2014 count (held on January 3, 2015), 17 (44%) of the 38 species observed were seen exclusively or primarily at feeders, and approximately one-third of the individual birds counted were at feeders. The percentage of individuals counted which are at least partially dependent on feeders is even greater. For example, most Rock Pigeons (Columba livia) and Mallards (Anas platyrhynchos) are not counted when they are at feeders (as they are counted at their communal roosting sites), but both of these species are dependent on feeders in the winter months.

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When redpolls arrive for the winter in the Adirondacks, they can be found feeding on wild food (e.g., birch and alder seeds); redpolls are also seen at bird feeders, especially those stocked with nyjer seed or sunflower chips/hearts. Because the birds travel in flocks, having many feeders attracts and holds the birds, as the large flocks can be accommodated. On the SLCBC, most people do not put out more than a couple of feeders, so the redpolls are particularly concentrated at the three or four houses in the count territory with many feeders (e.g., with > 100 feeding perches or where a deck railing, porch, picnic table, or cleared area on the ground has been sprinkled with nyjer or sunflower hearts). The scarcity of redpolls on counts prior to 1980 (maximum count was 31 individuals; see Figure 10) is likely due to the near absence of feeders, especially groups of several feeders with either nyjer or sunflower hearts. Similarly, American Goldfinches and Pine Siskins tend to be concentrated at homes with multiple nyjer or sunflower heart feeders. Purple Finches, Blue Jays, and Red-breasted Nuthatches tend to concentrate at home with feeders stocked with black oil sunflower seed or sunflower hearts. Pine Grosbeaks occasionally come to black oil sunflower seed feeders but are more frequently observed eating soft mast, especially mountain ash seeds and crab apples (Malus spp.). Prior to 1975, there were only three counts exceeding 100 individuals for these six species collectively. Since 1975, however, there have been 41 counts exceeding 100 individuals and six counts exceeding 1000 individuals (Figures 9-11). This is due not only to better count coverage by more participants but also, particularly, to more people feeding birds with appropriate seeds (nyjer, sunflower hearts, and black oil sunflower). Historically (in the 1970s and prior), most feeders in the area appeared to be stocked with a seed mix of millet, milo, and a few sunflower seeds that appealed to few birds except Mourning Doves and the one or two flocks of House Sparrows (Passer domesticus) that persisted in the count territory.

CONCLUSIONS Sixty years of data of bird occurrences on the Saranac Lake Christmas Bird Count, consistently collected by citizen scientists since 1975, reveal changes in the winter bird populations in the central Adirondack Mountains of upstate New York. The data also reveal a primarily biannual pattern of occurrence of winter finches, a result of their species-specific dependence on mast crops of spruce, birch, ash, and other trees. Key places to see winter birds include the Paul Smiths College Visitor Interpretive Center and the SUNY College of Environmental Science and Forestry Adirondack Interpretive Center in Newcomb. Contacting an Adirondack guide who specializes in birding trips is another excellent way to see winter birds in the Adirondacks. To participate in a CBC in your area, contact the local Audubon Society chapter (see Thaxton this issue).

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Table 1. Number of counts in which a species was recorded in two time periods: 1947-1968 (n = 19) and 1975-2014 (n = 40) (only dramatic increases in species occurrence are included; listed in taxonomic order). SPECIES

SCIENTIFIC NAME/FAMILY

1947-1968

1975-2014

Canada Goose

Branta canadensis 1 11

Hooded Merganser

Lophodytes cucullatus 2

Common Merganser

Mergus merganser 2 13

Wild Turkey

Meleagris gallopavo 0 17

Great Blue Heron

Ardea herodias 2 9

Accipiters (3 spp.)

Accipitridae

Bald Eagle

Haliaeetus leucocephalus

Buteos (2 spp.)

Accipitridae

Gulls (3 spp.)

Laridae

Mourning Dove

Zenaida macroura

Barred Owl

Strix varia

American Three-Toed Woodpecker

Picoides dorsalis

Black-Backed Woodpecker

Picoides arcticus

Gray Jay

Perisoreus canadensis

Common Raven

Corvus corax

Tufted Titmouse

Baeolophus bicolor

Carolina Wren

Thryothorus ludovicianus

American Robin

Turdus migratorius

Bohemian Waxwing

Bombycilla garrulus

Northern Cardinal

Cardinalis cardinalis

Common Grackle

Quiscalus quiscula

House Finch

Haemorhous mexicanus

Hoary Redpoll

Acanthis hornemanni

0 8

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Table 2. Distribution of “top five” and mean counts for five species in years of excellent, good/fair, or poor mast conifer crops, especially spruce and fir (listed in taxonomic order). NUMBER OF TIMES IN TOP 5 (OUT OF 5)

CONIFER MAST

PRIMARY FOOD

EXCELLENT

GOOD/FAIR

POOR

Blue Jay

Acorns, beechnuts

Red-breasted Nuthatch

Buds, fruits, seeds

Purple Finch

Spruce

White-winged Crossbill

Spruce, hemlock, tamarack

Pine Siskin

Hemlock, birch

Blue Jay

211

222

134

Red-breasted Nuthatch

151

119

Purple Finch

243

White-winged Crossbill

134

Pine Siskin

334

356

MEAN COUNT (NUMBER OF INDIVIDUALS)

Figure 1: Saranac Lake Christmas Bird Count, Birds Recorded and Participation, 1947-2014

Figure 2: Saranac Lake Christmas Bird Count, Bird Species Recorded and Participation, 1947-2014

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Figure 3: Saranac Lake Christmas Bird Count location

Figure 4: Saranac Lake Christmas Bird Count size and road distribution

Figure 5: Saranac Lake Christmas Bird Count, Observation Records and Party Hours, 1947-2014

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Figure 6: Saranac Lake Christmas Bird Count, Wild Turkey, American Crow, and Common Raven Records, 1947-2014

Figure 7: Saranac Lake Christmas Bird Count, House Finch, 1975-2014

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Figure 8: Saranac Lake Christmas Bird Count Evening Grosbeak with Spruce Budworm Outbreaks, 1947-2014

Figure 9: Saranac Lake Christmas Bird Count, Red-breasted Nuthatch, White-winged Crossbill, and Pine Siskin with annual quality of conifer seed mast crop, 1947-2014. (Note breaks in y-axes.)

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Figure 10: Saranac Lake Christmas Bird Count, Redpolls, American Goldfinch, and Pine Grosbeak, 1975-2014

Figure 11: Saranac Lake Christmas Bird Count, Purple Finch and Blue Jay, 1975-2014. (Note break in y-axis.)

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ACKNOWLEDGEMENTS

The author acknowledges Ezra Schwartzberg of Adirondack Research (www.adkres.org) for preparing the figures and calculating the correlation coefficients. L I TE R AT U R E C I T E D

Andrle, R.F. and J.R. Carroll. 1968. The Atlas of Breeding Birds in New York State. Ithaca, New York: Cornell University Press. Audubon. Accessed in August 2015 from https://www.audubon.org/content/historychristmas-bird-count. Beier, C. M., J.C. Stella, M. Dovčiak, and S.A. McNulty. 2012. “Local climatic drivers of changes in phenology at a boreal-temperate ecotone in eastern North America,” Climatic Change, 115:399-417. Bolgiano, N.C. 2004. Cause and effect: changes in boreal bird irruptions in eastern American relative to the 1970s spruce budworm infestation,” American Birds, 58:27-33. Bowman, J., R.D. Phoenix, A. Sugar, F.N. Dawson, and G. Holborn. 2008. “Spatial and temporal dynamics of small mammals at a regional scale in Canadian boreal forest,” Journal of Mammalogy, 89:381-387. Center for Disease Control. 2015. West Nile Virus & dead birds. Accessed in August 2015 from http://www.cdc.gov/westnile/faq/deadbirds.html. Crocoll, S. 2008. “Northern Goshawk,” in McGowan, K. J., and K. Corwin, Eds. The Second Atlas of Breeding Birds in New York State, pp 196-197. Ithaca, NY: Cornell University Press. DeGraff, L.W. 1973. “Return of the wild turkey,” Conservationist, 28:24-27, 47. Driscoll, M.J.L. 2008. “House Finch,” in McGowan, K. J., and K. Corwin, Eds. The Second Atlas of Breeding Birds in New York State, pp 610-611. Ithaca, NY: Cornell University Press. Jensen, P.G., C.L. Demers, S.A. McNulty, W. Jakubas, and M.M. Humphries. 2012. “Marten and fisher responses to fluctuations in prey populations and mast crops in the northern hardwood forest,” Journal of Wildlife Management, 76:489-502. DOI: 10.1002/ jwmg.322. Johnsgard, P.A. and T.G. Shane. 2009. “Four decades of Christmas Bird Counts in the Great Plains: Ornithological evidence of a changing climate,” Papers in Ornithology, Paper 46. Available at http://digitalcommons.unl.edu/biosciornithology/46.

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Koenig, W.D. and J.M.H. Knops. 2000. “Patterns of annual seed production by Northern Hemisphere trees: a global perspective,” The American Naturalist, 155:59–69. Link, W.A. and J.R. Sauer. 1999. “Controlling for varying effort in count surveys— an analysis of Christmas Bird Count Data,” Journal of Agricultural, Biological & Environmental Statistics, 4(2):116-125. Mason, N.A. and S.A. Taylor. 2015. “Differentially expressed genes match bill morphology and plumage despite largely undifferentiated genomes in a Holarctic songbird,” Molecular Ecology, 24: 3009-3025. McGowan, K. J., and K. Corwin, Eds. 2008. The Second Atlas of Breeding Birds in New York State. Ithaca, NY: Cornell University Press. McNulty, S. 2015. Email to author, 29 August 2015. Mineau, P. and L.J. Brownlee. 2005. “Road salts and birds: an assessment of the risk with particular emphasis on winter finch mortality,” Wildlife Society Bulletin, 33(3):835-841. Neily, L.E. 2011. “Ron Pittaway’s past years’ winter finch forecasts.” Available at http://www.neilyworld.com/neilyworld/pittaway-old.htm. Niven, D.K., G.S. Butcher, and G.T. Bancroft. 2009. “Christmas bird counts and climate change: northward shifts in early winter abundance,” American Birds, 63: 10-15. NYS DEC. 2015. “Bald eagle fact sheet.” Accessed in August 2015 from http://www.dec.ny.gov/animals/74052.html. Pittaway, R. 2014. Winter finch basics. Available at http://jeaniron.ca/2012/winterfinches.htm. Pittaway, R. 2015. “Winter finch forecast 2015-2016.” Available at http://jeaniron.ca/2015/ forecast15.htm. Stager J.C., S.A. McNulty, S.A. Beier, and C.M. Chiaranzelli. 2009. “Historical patterns and effects of changes in Adirondack climates since the early 20th century,” Adirondack Journal of Environmental Studies, 15:22–38. Young, M.A. 2008. “Evening Grosbeak,” in McGowan, K.J. and K. Corwin, Eds. The Second Atlas of Breeding Birds in New York State, pp 620-621. Ithaca, NY: Cornell University Press. Zuckerberg, B., A.M. Woods, and W.F. Porter. 2009. “Poleward shifts in breeding bird distributions in New York State,” Global Change Biology, 15:1866-1883. DOI: 10.1111/ j.1365-2486.2009.01878.x

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RUSTY BLACKBIRDS IN NEW YORK STATE: Ecology, Current Status, and Future STACY MCNULTY, 1 MICHALE J. GLENNON, 2 AND MELANIE MCCORMACK 3,4

1. State University of New York College of Environmental Science and Forestry Adirondack Ecological Center, 6312 State Route 28N, Newcomb, NY 12852, smcnulty@esf.edu 2. Wildlife Conservation Society Adirondack Communities and Conservation Program,132 Bloomingdale Avenue, Suite 2, Saranac Lake, NY, 12983, mglennon@wcs.org 3. Green Mountain College, 1 Brennan Circle, Poultney, Vermont 05764 4. Current address: ICF International, 405 W Boxelder Rd Suite A5, Gillette, WY 82718, Melanie.mccormack@icfi.com

INTRODUCTION The Rusty Blackbird (Euphagus carolinus) suffers from a case of mistaken identity. Rusty Blackbirds, or “rusties,” are so named after their autumn plumage, when their glossy black feathers are edged with a soft brown color—something Adirondackers might only see during the birds’ fall migration through the North Country or on wintertime travels through the southeastern US. Rusties are yellow-eyed blackbirds easily confused with other Icterids such as Red-winged Blackbirds (Agelaius phoeniceus) or Common Grackles (Quiscalus quiscula). Rusty Blackbirds seldom stand out in a crowd, as they often flock with other blackbird species. Yet the Rusty Blackbird is one of the sentinel species of the continent’s boreal ecosystems, and recent efforts to determine the bird’s status in New York State have resulted in serious cause for concern. Our objective is to share the collective knowledge gained from over a decade of studying this cryptic northern bird in the Adirondacks, to include what is known about breeding Rusty Blackbird populations in similar regions, and to explore a possible future for the species in New York.

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NATURAL HISTORY AND CONSERVATION STATUS The Rusty Blackbird’s Latin name means “good eater.” The moniker is an apt description for a bird that has flexible food habits, from snagging dragonflies at the edges of beaver ponds in the far northern forest to foraging for pecans in its Atlantic coastal plain wintering range (Avery 1995, Newell Wohner et al. 2015). Rusty Blackbirds summer in boreal wetlands across Canada, Alaska, and parts of New England and New York. The Adirondack region is disjunct (>200 km) from the primary breeding range for this bird of cool, wet, sphagnum-dominated bogs and moist woods, leading to potential implications for genetic flow and conservation (see Kirchman and Ralston this issue). Rusty Blackbirds are adapted to natural disturbances (e.g., fire, wind storms, insect outbreaks, and beaver activity) that create patchy, coniferous regeneration within wetland complexes. Sites with wetlands and conifer-dominated or young conifer patches are suitable for nesting. Nests are typically located in or in close proximity to wetlands, as the birds’ primary food supply during the breeding season consists of aquatic macroinvertebrates such as dragonflies, snails, caterpillars, and beetles. Rusties usually nest in live spruce (Picea spp.) or balsam fir (Abies balsamea) trees surrounded by regenerating conifer stands or alder patches in wetlands. A recent study in Maine and New Hampshire found the mean nest tree height was 2.47 m and mean tree diameter was 4.14 cm (Luepold et al. 2015); this accords well with studies in Maine (Powell et al. 2010a) and coastal Alaska (Matsuoka et al. 2010). New England nest success was relatively high at 46.6% (n = 65 nests) and best in thick conifer cover (Luepold et al. 2015). Egg and nestling predation rose in the summer after a good conifer cone crop (Luepold et al. 2015), suggesting predator numbers and/or behavior varies through time. The species has experienced perhaps the most significant population decline across its range ever documented among extant North American birds (>90% since 1960; Greenberg and Droege 1999, Niven et al. 2004). The New York State Breeding Bird Atlas confirmed Rusty Blackbirds breeding in 51, 5 km blocks in 1980-85; the number of confirmed blocks dropped to 32 in 2000-2005 (McGowan and Corwin 2008). Larger landscape patterns are also at work: using North American Breeding Bird Survey (BBS) data, McClure et al. (2012) showed a northward retraction of >140km from the southern range limit over the past 40 years. The factors responsible for this boreal wetland bird’s drop in numbers are unknown (Greenberg and Matsuoka 2010), but climate change, mercury bioaccumulation, and habitat fragmentation and degradation on breeding and/or wintering grounds are among the factors that may play a role. Edmonds et al. (2010) found mercury concentrations in breeding Rusty Blackbirds from New England and eastern Canada exceeded published minimum levels for songbirds, and mercury bioaccumulation in this Acadian forest population is among the highest reported at sites without a nearby industrial source of

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mercury. Directional climate change from the Pacific Decadal Oscillation (ocean surface temperatures) has been implicated in a northward range shift over the past forty years (McClure et al. 2012). In New York, the Department of Environmental Conservation (NYSDEC) recognizes the Rusty Blackbird as a â&#x20AC;&#x153;High Priority Species of Greatest Conservation Needâ&#x20AC;? and it is considered Rare or Threatened throughout the east. Vermont recently listed the species as state endangered; in New Hampshire and Maine the designation is species of special concern.

METHODS AND RESULTS Several recent studies have been conducted to assess Rusty Blackbird distribution and status in the Adirondack region. We present the methods and results of each study here. A. Boreal bird monitoring, 2003-present. The Wildlife Conservation Society (WCS), together with the New York State Department of Environmental Conservation (NYSDEC), has documented the occurrence of Rusty Blackbird and other boreal birds in the Adirondacks since 2003. They have surveyed more than 80 boreal habitats to document presence of 13 target boreal birds as well as other avian species (Glennon 2014a). Surveys are conducted via standard point count methods to assess presence/absence of target species along transects of five points spaced at least 250 m apart within boreal wetland habitats (Ralph et al. 1995). All points are sampled with fixed radius, 10 minute point counts between the hours of 5:00 and 9:00 am and, at each sample point, birds are recorded by species, time period of detection (i.e., 0-3 minutes, 3-5 minutes, 5-10 minutes), activity (i.e., singing, calling, individual seen), and whether or not birds are within 50 m of the observer. Date, start and end time for each survey, ambient temperature, and sky and wind conditions are recorded for each count and surveys are conducted by trained observers, the majority of whom have conducted counts for three or more of the project years. Most surveys are conducted on foot; surveys in boreal river corridors are conducted by boat. Site selection for WCS boreal bird survey locations was conducted by consulting a variety of data sources including Adirondack Park Agency wetlands inventory data, New York State Breeding Bird Atlas data (Andrle and Carroll 1988, McGowan and Corwin 2008), postings to the Northern New York Breeding Bird Listserv (a resource for many regional birders), and local expert opinion. Between 2007 and 2011, 58 sites were surveyed intensively as part of a New York State Wildlife Grant project (Glennon 2014a). These sites ranged in size from 0.04 to 6.06 km2 and were widely distributed throughout the boreal zone of the Adirondacks ranging from the northern border in the Debar Mountain Wild Forest to the southwest region in the Moose River Plains Wild Forest. Approximately 40 additional sites have been surveyed at least once between 2003 and 2015. Since 2012, WCS and NYSDEC have collaborated on this work, with counts conducted by NYSDEC field technicians and analytical support provided by WCS.

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Glennon (2014a) examined occupancy dynamics of Rusty Blackbird and seven other bird species in lowland boreal forest wetlands, examining the influence of wetland size and connectivity, and other variables associated with climate change and habitat fragmentation on colonization and extinction dynamics for the period 2007 – 2011. Among the 1,305 boreal bird detections analyzed for this analysis, Rusty Blackbird made up 2% of all detections. Over this five year period, the Rusty Blackbird was more likely to colonize larger, more connected wetlands and more likely to abandon those wetlands that were smaller and more isolated. This pattern conforms to metapopulation theory for species inhabiting naturally patchy habitats like boreal wetlands (Hanski 1998). However, responses to latitude and elevation were variable. Proximity of human infrastructure (e.g., roads, buildings) was the most consistent driver of short-term dynamics for Rusty Blackbird and other species, with birds two-thirds more likely to colonize low human-impact sites and go extinct from more impacted sites (Glennon 2014a). When observations were corrected for detection probability (MacKenzie et al. 2006), Rusty Blackbird was estimated to occupy 23% of sites surveyed (Glennon 2014a). The pattern of occupancy during 2007 – 2011 was stable, with an estimated colonization rate of 10% and extinction rate of 34%. However, in recent longer-term analysis incorporating data through 2013, Rusty Blackbird declined to 16% of sites occupied in 2013 (Glennon unpub. data). Among Adirondack sampling locations, over time Rusty Blackbird appears most likely to colonize large wetlands at higher elevations and most likely to disappear from isolated wetlands in closer proximity to human infrastructure. B. Digital Spot Mapping in Spring Pond Bog, 2009. Jablonski (2010) conducted digital mapping within the Spring Pond Bog complex in St. Lawrence County. He completely surveyed five grids of 0.09 km2 during each of five visits in 2009; this technique is similar to intensive territory or spot mapping (Jablonski et al. 2012). He recorded 153 total detections of 12 lowland boreal bird species, including eight Rusty detections from four different sites. Among these four sites, there were five different vegetation communities: black spruce-tamarack (Picea mariana-Larix laricina) bog, shrub swamp, beaver pond, shallow emergent marsh, and spruce-northern hardwood forest. While the latter three are not specifically lowland boreal habitats, in these cases they were within the lowland boreal landscape mosaic. Of the four sites where Rusties were detected, tree canopy cover was generally sparse (< 35%), while the amount of open water was high (mean cover 11% ± 18) compared to all 22 sites (mean 2.3%). Tall (>2 m) and short (<2 m) shrub cover was always less than 38% where Rusty Blackbirds were detected. All four sites were on the edge of a flooded beaver pond or abandoned beaver-impounded meadow. C. Wetland point counts, 2010. McCormack (2012) conducted surveys for Rusty Blackbirds in 2010 at 15 wetland complexes in the Adirondacks. A total of 75 points, spaced a minimum of 250 m apart, were surveyed twice during the early breeding season (May to

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mid-June), when males are establishing breeding territories and have the highest likelihood of detection. At each point the observer listened for three minutes before playing a 30 second recording of a Rusty Blackbird vocalization (recorded in NY by Peter Kellogg and stored at the Cornell Lab of Ornithology), after which the observer listened for an additional 3.5 minutes, for a total point count time of seven minutes. All individuals that were heard or seen within 100 m during the seven minute period were recorded. Rusty Blackbirds were detected on eight out of 148 surveys at 8% of points (McCormack 2012). Fifteen individuals were recorded, including a pair with two fledglings at Spring Pond Bog. Predicted occupancy of Rusty Blackbirds in this study was 0.13 ± 0.05, similar to Glennon (2014a) but noticeably lower than comparable studies conducted in New England (0.37 ± 0.12 by Powell 2008) and Alaska (0.51 ± 0.21 by Matsuoka et al. 2010). For comparison, at 260 sites in Vermont and Maine in 2012, Scarl (2013) reported a < 10% raw detection rate; this was similar to historical rusty detection rates in Maine in 2006-7, despite efforts to increase detection in 2012 using playback calls and a nearly 15-minute point count. McCormack (2012) used program PRESENCE to model Rusty Blackbird occupancy as a function of site-specific and sampling covariates using single-season analysis. Two sets of occupancy models were run to evaluate the influence of localized habitat (within 100 m) and landscape scale (500 m-10 km) features on Rusty Blackbird occupancy. Due to small sample size, only single-variable models were used. Indicators of Rusty Blackbird occupancy at the habitat scale included alder (Alnus sp.), northern white cedar (Thuja occidentalis), exposed mud, and upland pines (Pinus spp.), all of which have been identified in previous studies as features that provide either nesting or foraging habitat. At the landscape scale, the amount of boreal acidic peatland within 10 km was the strongest indicator of occupancy. All wetland types, with the exception of open bog, were positive indicators of occupancy at the landscape scale. D. Targeted expert observation, 2012-13. Twelve major wetland complexes with known prior Rusty Blackbird occupancy were searched for bird presence during May-July 2012 and April-June 2013. Volunteer expert birders drove hundreds of miles and hiked numerous trails and wetlands, noting bird and predator presence, potential nesting and foraging competitors, and key habitat features. Twenty-seven separate reports of Rusty Blackbirds were received including two revisits in the same season. The data were combined with confirmed sightings from the Northern New York Breeding Bird Listserv (a resource for regional birders). Over two years, eight sites contained adults or family groups; two in 2012 and six in 2013 (with multiple locations and years in the Shingle Shanty Preserve wetland complex). Many of the occupied sites had a history of beaver activity that created or altered the flooded conditions favored by Rusty Blackbirds for foraging and/or snags for perching. No occupied site had recent logging noted, and one site had potential competing species (Red-winged Blackbirds and Common Grackles).

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DISCUSSION Rusty Blackbirds declined range-wide several decades ago, and our recent studies suggest Adirondack-breeding birds occupy even fewer locations today than in 2003. Glennon (2014a) provides evidence that Rusty Blackbirds are nesting in higher latitude and elevation sites in the Adirondacks than a decade ago, lending credence to the similar continentalscale conclusion of McClure et al. (2012). Declines in site occupancy across a broader suite of boreal birds in the Adirondacks (Glennon 2014a, b) suggest that range contraction from climate-driven hydrological or wetland-related changes may explain the loss of Rusty Blackbird and other species. Within the spruce-fir forest of the Adirondacks, wetlands are more important than forest composition in driving Rusty Blackbird breeding habitat selection at the landscape scale. Wetland area was the second most important factor in controlling which sites rusties are likely to colonize, and wetland isolation was the most important factor in controlling which sites they are most likely to drop out of over time (Glennon 2014a). McCormack (2012) also found that occupancy was positively correlated to the amount of boreal wetland habitat at the landscape scale. In New England, Luepold et al. (2015) support this, finding the probability of Rusty Blackbird selection of a site for nesting was three times more likely when wetland cover increased as compared to a commensurate increase in young conifer cover. While total extent and connectivity of wetlands greatly influences site selection, it is imperative to note that fine-scale habitat features are also important to breeding Rusty Blackbird occupancy. Luepold et al. (2015) found low percent canopy cover and patches of dense, short conifers to be the most important nesting habitat variables. This accords with Jablonskiâ&#x20AC;&#x2122;s (2010) habitat assessment in the Adirondacks. Another common feature of nest sites in Maine and New Hampshire was the presence of high perches within a few meters of the nest. Perches were often snags, and paper birch (Betula papyrifera) was a common species used for vocalizing and defending territory (Luepold et al. 2015). McCormack (2012) and Scarl (2013) identified shallow puddles and exposed mud as features key to foraging birds. Further, many of the wetlands used are not â&#x20AC;&#x153;mappableâ&#x20AC;? wetlands: the birds readily feed in roadside ditches, seeps, and isolated ephemeral pools, none of which can be reliably detected with aerial imagery and few of which are delineated on National Wetland Inventory maps. Indeed, different factors may govern breeding habitat selection at different scales. Food availability is important at the home range/territory and larger spatial scales, while nest site selection may be based on microhabitat features related to risk of nest predation and independent of foraging habitat. This decoupling of nest and foraging habitat selection cues may be especially strong for species like Rusties with high mobility and large home ranges. Powell (2010b) determined the mean home range in Maine to be 0.38 km2 (94 acres), a

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larger area requirement compared to other Icterid species. This may reflect differential sex roles; males choose a territory in spring, whereas females first choose the male and then the nest site within the male’s territory (Luepold et al. 2015). There is likely sufficient suitable habitat for Rusty Blackbirds to nest in the Adirondacks in terms of forest structure and composition and openings within wetland complexes; three lines of evidence support this. First, windthrow remains an important form of local natural disturbance, and severe storms that can blow down large areas and create short, dense conifer regeneration are, if anything, becoming more frequent across the U.S. (Melillo et al. 2014). Second, the small number of places where Rusties were detected more than once in the past twelve years were not near recent timber harvest operations. Although logging is not as extensive today as in the late 1800s (McMartin 1994), harvesting of forests throughout the Northeast remains a disturbance factor of primary importance (Canham et al. 2013). In our Adirondack studies, we rarely detected nesting birds in sites that were logged since 2003. Third, the expansion of New York beaver populations starting in 1900 (NYSDEC 1992) should be favorable to creation of shallow wetlands and mudflats, yet Rusty Blackbird populations have continued to decline. Certain forest management activities may emulate natural conditions favorable to breeding Rusty Blackbirds: of 72 nests studied in New Hampshire and Maine, 63 were in managed stands and those that were not were mostly in beaver-influenced wetlands (Luepold et al. 2015). Some 90% of nests were located near a forest edge/open border, such as a skid road, a single-tree canopy gap, or an isolated patch of young conifers surrounded by a recent clearcut (Luepold et al. 2015). However, no experimental studies have been carried out to assess the response of rusties to logging or other factors, making definitive answers difficult to discern. In addition to worsening conditions at the Adirondack range margin, breeding habitat for Rusty Blackbird and other species is also negatively impacted by mercury deposition throughout the Northeast (Evers et al. 2012). Extensive study of mercury levels in terrestrial and aquatic food chains indicates mercury—a potent neurotoxin—should be considered a threat to Rusties and other species (Schoch et al. 2010, Sauer and Evers this issue). The Rusty Blackbird may be particularly sensitive for three reasons: 1) it feeds on aquatic invertebrates and spiders known to harbor high levels of mercury; 2) the acidic nature of some of the boreal peatlands in which it breeds results in environmental conditions whereby mercury is more readily converted to its biologically available form of methylmercury (Mitchell et al. 2008); and 3) water level fluctuations in wetlands enhance mercury methylation (Evers et al. 2007), particularly beaver-impounded systems. Mercury has been documented at high levels in eastern Rusty Blackbird populations and this environmental pollutant should not be overlooked as a potential contributor to the species’ decline (Edmonds et al. 2010).

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Neither predators nor competitors have much support as a cause of multi-decade decline of the Rusty Blackbird. Although we do not have nest data for the Adirondacks, New England Rusty Blackbirds had good overall nest success (at least 59% produced one or more fledglings) despite higher predator pressure in some years, particularly when red squirrel populations were high after a large conifer cone crop (Luepold et al. 2015, Foss and Wohner unpub. data). Tree seed numbers and small mammal populations tend to be synchronous and cyclical in conifers in Canada (Krebs et al. 2014) and the deciduous/coniferous woods of the Adirondacks (Jensen et al. 2012); a multi-year cycle has been operating in the boreal forest for decades if not longer. Common Grackles and Red-winged Blackbirds are often present in wetlands with Rusty Blackbirds, but our observations suggest competitive interactions do not result in significant nest abandonment by Rusties, although it is possible the stress of maintaining territories is detrimental. No clear cause for the Rusty Blackbird decline has been found to date; this is unsurprising because migratory birds are impacted by multiple factors throughout their life cycle. Also, low detectability confounds researchersâ&#x20AC;&#x2122; ability to document population trends for several reasons. The Rusty Blackbird is cryptic in behavior and song, highly mobile both intra- and inter-annually (Scarl 2013), and has one of the earliest breeding seasons of any migratory species, often setting up territories when wetlands are still snowy and inaccessible to humans. The birds can be present but not detected, particularly during egg incubation. Recent research indicates longer, targeted surveys at wetlands (e.g., 30 minutes) may increase detectability over traditional 10-minute point counts (Foss and Newell Wohner unpub. data). Despite these characteristics, ample survey effort since 2003 indicates Rusty Blackbirds presently occupy few sites in the Adirondacks. If the breeding range of Rusties is expanding northward, it may offset the southern range retraction, but survey routes for the BBS do not cover far-north territory and make monitoring this potential change difficult (McClure et al. 2012). The fact remains that range-wide Rusty Blackbird abundance dropped an estimated 5-12.5% per year since the 1970s (Greenberg et al. 2011). Whether this is due to conversion of wooded wetlands to farming and other human land use in the southeastern United States, climate-mediated shifts in breeding site food or habitat suitability, pollution, or a combination of these and other factors is not yet known. The outlook for continued Rusty Blackbird breeding in New York is not bright. There are a few holdout locations in the Adirondacks where the birds remain (Table 1). Using several predictors of occupancy, McCormack (2012) determined that sites in Massawepie Mire, Bloomingdale Bog, and Shingle Shanty Preserve provide the most suitable habitat for rusties. These wetlands represent three of the four largest wetland complexes in the Adirondacks. Historically the species nested in all three of these wetlands, but in recent years only two of these sites have had breeding Rusty Blackbirds. A high (>80%) probability of extinction at previous Rusty Blackbird sites estimated by McClure et al. (2012) effectively erases the Adirondack region from the rustiesâ&#x20AC;&#x2122; summer range.

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CONCLUSIONS The declining trend of Rusty Blackbird occupancy shown by Glennon (2014b) and our data combined with recent failures to detect birds in “classically rusty” wetland complexes in New York State is a call to action. Rusty Blackbird nest habitat results from a complex process of interacting disturbances that is dynamic across space and time. Wetland area and connectivity are key drivers of Rusty Blackbird dynamics in the Adirondacks. Rusties are adapted to natural disturbances that create patchy, coniferous regeneration and appear to favor large wetland complexes for breeding, which is unsurprising in that they have larger home ranges than many other boreal songbirds. Management for landscape species like Rusty Blackbirds is particularly challenging because of the patchwork of private and public ownership and diversity of land uses permitted in the Adirondack Park. Many of the largest wetland complexes are already relatively wellprotected, but it is important to note that the majority of wetlands are small. Some are vulnerable to threats such as encroaching development (e.g., Silver Lake Bog) or disturbance from recreation (e.g., Ferd’s Bog). From a conservation standpoint, small wetlands may also provide key migratory stopover or breeding habitat (Glennon 2014a). Additionally, adjacent upland habitats that Rusties may use for nesting are often not protected from fragmentation (see Glennon and Kretser this issue). This is especially true at some of the park’s largest wetlands, including Spring Pond Bog and Bloomingdale Bog, which both lie adjacent to two of the most populated towns in the Adirondacks. Though current trends suggest that the long-term outlook for Rusty Blackbird in the Adirondacks is not good, boreal wetland complexes will remain vital to whatever suite of species may inhabit them in the future. Focusing on maintenance of ecological function in these places, rather than maintaining a specific set of species, is increasingly espoused by scientists as an important conservation strategy (Anderson and Ferree 2010). Adirondack wetlands are important not only as primary breeding sites for current and future species (e.g., Hitch and Leberg 2007) but also as stopover sites for Rusty Blackbirds and other mobile species whose breeding distribution lies primarily to the north of the Adirondacks. Wetland complexes embedded in intact forest landscapes can provide high-value stopover habitat, because they are places where all necessary resources (i.e., food, water, and shelter) are relatively abundant (Mehlman et al. 2005). Protecting them from fragmentation and disturbance will help maintain this important ecological function. We suggest four recommendations to enhance understanding and protection of the Rusty Blackbird in New York: 1. Monitor the Adirondack population. Monitoring is critical to understanding the status of Rusty Blackbird in the Adirondacks, and WCS is working with NYSDEC to seek ways to sustain some level of continual monitoring of wetlands for a suite of boreal species. Citizen science is a powerful tool for monitoring birds; the next Breeding Bird Atlas begins

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in 2020 and it is critical that volunteers survey boreal wetlands for Rusty Blackbirds and other boreal species. The Rusty Blackbird Spring Migration Blitz (http://rustyblackbird. org/outreach/migration-blitz) is an effort to evaluate migratory timing and “hot spots” for stopovers throughout the Rusties’ continental habitat that will also provide opportunities to contribute data and learn about breeding and non-breeding habitat use. We encourage participation in these efforts. 2. Address pollution and human disturbance. Reducing pollution is important, as is controlling invasive species that threaten the diversity and structure of boreal wetlands. Continued support of organizations such as the Biodiversity Research Institute and Adirondack Park Invasive Plant Program is essential. These organizations are working to enact regional, national, and international policy change on mercury and to increase awareness of and response to aggressive, non-native species, respectively. 3. Protect wetland quality and connectivity from fragmentation. Proximity of human infrastructure may be an important factor in moderating dynamics of Rusty Blackbird habitat occupancy in the Adirondacks and may be particularly significant in areas adjacent to small and isolated wetlands. Buffering these wetlands from road and infrastructure development will help ensure that forested wetlands maintain their vital role in the overall network of sites important to successful Rusty Blackbird breeding. 4. Address information gaps. Examination of the boreal wetland ecotype for a climatehydrology relationship to nesting and foraging Rusty Blackbirds is a prime area for study. Also, research on habitat characteristics, land use change and management in concert with other factors is desirable; while assessment of the “footprint” of development (Glennon and Kretser this issue) can indicate impacts from roads and infrastructure, it does not take into account the current structure and composition of forests in boreal wetland complexes. Forest management may promote Rusty Blackbird habitat by leaving tall snags as perching sites for birds and creating a varied landscape with openings, but the amount of area needed of different habitat types and ages is not known and the impact of specific harvest activities on nesting needs further study. Identifying small and ephemeral wetlands could improve habitat modeling, as would having current stand age and attribute data. Researchers can utilize new geospatial technology to identify small and ephemeral wetlands. Genetic samples would shed light on the degree of inbreeding of Adirondack-breeding birds. There is a need to better understand Rusty Blackbird populations, including connectivity and demography, population viability, and variation in survival during the life cycle of the birds, especially in central Canada. The International Rusty Blackbird Working Group aids efforts toward understanding the species’ decline (Greenberg and Matsuoka 2010) and is a prime means to share information and assess conservation strategies. The Adirondack region is one of the most intact temperate forest landscapes worldwide and can be a model for conservation of Rusty Blackbirds into the future.

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Table 1. Wetland complexes with recent breeding season occupancy by Rusty Blackbirds in Adirondack Park. Only confirmed detections are included. Sites are listed in order of decreasing size after Glennon 2014a. SITE NAME TOWN COUNTY LAND YEAR WETLAND OTHER BEAVER PARCEL AREA (KM 2 ) ICTERID SIGN SPECIES PRESENT

Massawepie Piercefield St. Private 2012 6.06 N/a1 Yes, Mire Lawrence abandoned lodge Single Shanty Long Lake Hamilton Private 2013 3.52 None Preserve & Research Station

Beaver flooded

Dead Creek Wanakena St. Lawrence Flow

Five Ponds Wilderness

2013

2.50

None

N/a

Powley Road Arietta Hamilton

Ferris Lake Wild Forest

2013

1.30

None

N/a

Ferd’s Bog Inlet Hamilton Pigeon Lake 2013 0.59 N/a Yes, inactive Wilderness pond Sabbatis Long Lake Hamilton Whitney 2013 0.32 Circle Road Wilderness; private

Red-winged N/a blackbirds common grackles

1. N/a means no information available

ACKNOWLEDGEMENTS

Funding for the studies mentioned was provided by the New York State Wildlife Grant Program, Northern New York Audubon Society Cullman Grant Program, Edna Bailey Sussman Foundation and Wildlife Conservation Society. We thank the many technicians and volunteers who tirelessly surveyed for Rusty Blackbirds. C. Foss provided helpful comments on the manuscript. L I TE R AT U R E C I T E D

Andrle, R., and J. Carroll, Eds. 1988. The Atlas of Breeding Birds in New York State. Ithaca, NY: Cornell University Press. Avery, M. L. 1995. “Rusty Blackbird (Euphagus carolinus),” in The Birds of North America Online (A. Poole, and F. Gill, Eds.). Ithaca, NY: Cornell Laboratory of Ornithology. Canham, C.D., N. Rogers, and T. Buchholz. 2013. “Regional variation in forest harvest regimes in the northeastern United States,” Ecological Applications, 23(3):515-522. Edmonds, S. T., Evers, D. C., Cristol, D. A., Mettke-Hofmann, C., Powell, L. L., McGann, A. J., Armiger, J. W., Lane, O. P., Tessler, D. F., Newell, P., Heyden, K., O’Driscoll, N. J. 2010. “Geographic and Seasonal Variation in Mercury Exposure of the Declining Rusty Blackbird,” The Condor, 112(4):789-799. Available at http://www.bioone.org/doi/full/10.1525/cond.2010.100145. VOLUME 20

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Evers, D.C., A.K. Jackson, T.H. Tear and C.E. Osborne. 2012. Hidden Risk: Mercury in Terrestrial Ecosystems of the Northeast. Biodiversity Research Institute. Gorham, Maine. BRI Report 2012-07. 33 pp. Evers, D. C., Y. Han, C. T. Driscoll, N. C. Kamman, M. W. Goodale, K. Fallon Lambert, T. M. Holsen, C. Y. Chen, T. A. Clair, and T. Butler. 2007. “Biological mercury hotspots in the northeastern United States and southeastern Canada,” BioScience, 57:29-43. Available at http://dx.doi.org/10.1641/B570107. Glennon, M.J. 2014a. “Dynamics of boreal birds at the edge of their range in the Adirondack Park, NY,” Northeastern Naturalist, 21(1):NENHC-51-NENHC-71. Glennon, M.J. 2014b. “Protect our boreal birds,” Viewpoint, Adirondack Explorer, July/Aug. 2014. Greenberg, R. and S. M. Matsuoka. 2010. “Special Section: Rangewide Ecology of the Declining Rusty Blackbird Rusty Blackbird: Mysteries of a Species in Decline,” The Condor, 112(4):770-777. Greenberg, R., D. W. Demarest, S. M. Matsuoka, C. Mettke-Hofmann, M. L. Avery, P. J. Blancher, D. C. Evers, P. B. Hamel, K. A. Hobson, J. Luscier, D. K. Niven, L. L. Powell, and D. Shaw. 2011. “Understanding declines in Rusty Blackbirds,” pp 107– 126 in J. V. Wells (editor). Boreal birds of North America: a hemispheric view of their conservation links and significance, studies in Avian Biology (no. 41). Berkeley, CA: University of California Press. Available at http://digitalcommons.unl.edu/icwdm_usdanwrc/1294. Hanski, I. 1998. “Metapopulation dynamics,” Nature, 396:41-49. Hitch, A. T. and P. L. Leberg. 2007. “Breeding Distributions of North American Bird Species Moving North as a Result of Climate Change,” Conservation Biology, Volume 21, No. 2, 534–539. Jablonski,K. J. 2012. “Habitat associations of Adirondack lowland boreal birds at Spring Pond Bog, New York,” M.S. Thesis, State University of New York College of Environmental Science and Forestry. Jablonski, K., S. McNulty, and M. Schlesinger. 2010. “A digital spot-mapping method for avian field studies,” The Wilson Journal of Ornithology, 122:772-776. Krebs, C. J., R. Boonstra, S. Boutin, A. R. E. Sinclair, J. N. M. Smith, B. S. Gilbert, K. Martin, M. O’Donoghue, and R. Turkington. 2014. “Trophic dynamics of the boreal forests of the Kluane region,” Arctic, (KLRS 50th Anniversary Issue). Luepold, S.H.B., T. P. Hodgman, S. A. McNulty, J. Cohen, and C. R. Foss. 2015. “Habitat selection, nest survival and nest predators of Rusty Blackbirds in northern New England,” The Condor. Matsuoka, S. M., D. Shaw, P. Sinclair, J. Johnson, R. Corcoran, N. Dau, P. Meyers, and N. Rojek. 2010. “Nesting ecology of the Rusty Blackbird in Alaska and Canada,” The Condor, 112:810-824.

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McClure, C. J.W., Rolek, B. W., McDonald, K., Hill, G. E. 2012. “Climate change and the decline of a once common bird,” Ecology and Evolution, Open Access. doi: 10.1002/ece3.95. McCormack, M.M. 2012. “Rusty Blackbird Occupancy in the Adirondack Region of New York State,” M.S. Thesis, Green Mountain College, Poultney, VT. McGowan, K. J., and K. Corwin, Eds. 2008. The Second Atlas of Breeding Birds in New York State. Ithaca, NY: Cornell University Press. McMartin, B. 1994. The great forest of the Adirondacks. Utica, NY: North Country Books, 240 pp. Mehlman, D. W., S. E. Mabey, D. N. Ewert, C. Duncan, B. Abel, D. Cimprich, R. D. Sutter, and M. Woodrey. 2005. “Conserving stopover sites for forest-dwelling migrating landbirds,” The Auk, 122:1281–1290. Melillo, J. M., T.C. Richmond, and G. W. Yohe, Eds. 2014. Climate Change Impacts in the United States: The Third National Climate Assessment. U.S. Global Change Research Program, 841 pp. doi:10.7930/J0Z31WJ2. Mitchell, C.P.J., B.A. Branfireun, and R.K. Kolka. 2008. “Total mercury and methylmercury dynamics in upland-peatland watersheds during snowmelt,” Biogeochemistry, 90:225-241. Newell Wohner, P. J, R. J. Cooper, R. S. Greenberg and S. H. Schweitzer. 2015. “Weather Affects Diet Composition of Rusty Blackbirds Wintering in Suburban Landscapes,” The Journal of Wildlife Management, 9999:1–10. DOI: 10.1002/jwmg.984. New York State Department of Environmental Conservation (NYSDEC). 1992. Beaver management in New York State: history and specification of future program. Albany, NY. 87 pp. Powell, Luke L. 2008. “Rusty Blackbird Breeding Ecology in New England: Habitat selection, nest success, and home range,” M.S. Thesis, University of Maine, Orono, ME. Powell, L. L., T. P. Hodgman, W. E. Glanz, J. D. Osenton, and C. M. Fisher. 2010a. “Nest-site selection and nest survival of the Rusty Blackbird: Does timber management adjacent to wetlands create ecological traps?” The Condor, 112:800-809. Powell, L. L., T. P. Hodgman and W. E. Glanz. 2010b. “Home ranges of Rusty Blackbirds breeding in wetlands: How much would buffers from timber harvest protect habitat?” The Condor, 112:834-840. Schoch N., D. Evers , O. Lane, D. Yates, M. Duron, R. Hames, and J. Lowe. 2010. Biogeography of Mercury Contamination in New York State: Risk to Species of Greatest Conservation Need. Biodiversity Research Institute report submitted to: New York State Wildlife Grants Program. Scarl, J. 2013. Rusty Blackbirds 2012: Building Connections for a Declining Species. Vermont Center for Ecostudies.

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THE BIRDSBESAFE® CAT COLLAR COVER: Why Cats in New York Need It More Than Australian Cats to Decrease Songbird Mortality SUSAN K. WILLSON

Dept. of Biology, St. Lawrence University, 23 Romoda Dr., Canton, NY 13617 Email: swillson@stlawu.edu

INTRODUCTION Domestic cats are arguably the greatest anthropogenic threat to songbirds that currently exists, aside from habitat alteration and/or destruction (Loss et al. 2013). Although numerous campaigns have pushed for “cats indoors,” many cat owners are unwilling or unable to keep their pet cats indoors (American Bird Conservancy 2015). In rural New York, where many people keep farm animals, there is also a sizable population of barn cats that are kept specifically as outdoor pets to keep barnyard mouse populations in check. Although some owners choose to ignore the carnage their cats are inflicting on local birdlife, many others do in fact care about the barn swallows, savannah sparrows, and bluebirds that their barn cats are killing, as well as the backyard warblers, grosbeaks and catbirds in villages and hamlets across the North Country and the Adirondacks. Two recent studies on a relatively new cat collar device provide evidence that cat owners can in fact significantly decrease the number of birds that their cats are killing without affecting cat predation on barn rodents (Hall et al. 2015, Willson et al. 2015). The two studies, which were published within weeks of one another and which examined cat behavior on opposite ends of the globe, found varying levels of effectiveness in the use of the Birdsbesafe® cat collar cover (hereafter called BCC) as a device to decrease songbird mortality (Birdsbesafe® LLC). Here, I describe some of the main points of the two papers, one of which I co-authored, and I suggest a novel hypothesis that may explain the differences in results between the studies. These differences lead to important implications for North Country and Adirondack cat owners and suggest that the BCC will be more effective in northern regions of the mid-United States through Alaska and Canada than in lower latitude regions of the world such as Australia.

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THE DEVICE The BCC is a 2-inch wide cotton fabric tube that fits over a quick-release cat collar and pleats around the collar somewhat like a hair “scrunchie” or an Elizabethan collar (Figure 1). The premise of the BCC is that its bright colors and patterns, in hues of red, orange and yellow, may alert songbirds to the presence of an otherwise hidden, stalking cat. Songbirds have exceptional color vision with sensitivities across the color spectrum from ultraviolet through deep reds (Chen et al. 1986). This is called tetrachromatic vision, and it means that birds have higher sensitivities across at least four parts of the light spectrum than mammals; birds see colors that mammals are unable to differentiate. This ability sets birds apart from the limited visual spectrum used by most mammals, including humans. For example, humans cannot see in the ultraviolet part of the light spectrum (Hill and McGraw 2006). No scientific study had previously been carried out on the BCC’s efficacy, although anecdotal evidence from cat owners who used the device noted sharp declines in their cat’s success in hunting and catching birds (Birdsbesafe.com 2013).

HYPOTHESIS AND CONSERVATION IMPLICATIONS Life histories are the “schedules” that organisms follow, based on natural selection, that dictate important adaptations for a population including lifespan, age at maturity, fecundity (number of young per reproductive bout), and size of offspring (Stearns 1992). For example, an albatross has a “slow” life history, meaning it lives a long time (over 40 years), takes a long time to reach sexual maturity (up to 10 years), has one nestling at a time, and invests an extraordinary amount time in that one offspring before breeding again. An American Redstart has a much “faster” life history: quick to breed, large clutch size (up to 5 eggs), and a short lifespan with an annual adult mortality of 50-60% (Sherry and Holmes 1997). There are important life history differences among similar-sized songbirds in the north-temperate zone compared to the equatorial regions. In general, songbirds that breed in higher latitudes have shorter lifespans, lay larger clutches, and have a shorter breeding season than lower latitude birds (Martin et al. 2000). I posit that the well-researched life history differences that exist between north-latitude and equatorial bird species are tied to direct conservation management implications. These life history differences also correlate to physiological differences in relative testosterone increases in the breeding season in birds, with higher latitude birds exhibiting much higher increases in relative testosterone levels compared to baseline (non-breeding levels) (Hau et al. 2010, Hau et al. 2008, Goymann et al. 2004). The testosterone spike corresponds with a rush to acquire and defend territories, initiate nest-building, and raise young during the short breeding season. My suggestion here is that it also leads to relatively more distracted northern birds in comparison to their equatorial counterparts. The prediction is that northern birds may be more susceptible to predation during the breeding season and that avian life history theory has direct conservation management implications for devices like the BCC.

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Life history theory suggests that northern latitude breeding songbirds may regularly be caught and killed by domestic cats at a higher rate than lower latitude passerines. If this is the case, it would explain the wide difference in effectiveness of the BCC that was observed across the two recent studies in northern New York and Australia. It would also explain the results we found for northern New York birds in the spring breeding season, when testosterone levels are high, versus our results during the fall (post-breeding) season, which closely match results from Australia. These major life history differences in birds also imply that northern latitude areas are the locations where the BCCs should be most effective.

METHODOLOGY OF THE STUDIES Each of the studies was a test of the BCC and its effect on predation using a large sample size of domestic cats wearing the collar cover compared with the same cat groups not wearing the collar cover. Both studies focused on cats with a history of animal predation and excluded cats from the study that were not known hunters. Each study asked cat owners to collect and freeze any prey item that cats delivered to the house for identification. While each study examined predation on mammals as well as birds, I will focus on birds. Results for mammals in each study suggested that the BCCs were not effective at reducing mammal predation, likely because most mammal prey do not have color vision (Jacobs 2009).

The New York study My co-authors and I (Willson et al. 2015) carried out two seasonal trials. The first took place in September-November 2013 and the second in April-June 2014, both at 46° N latitude. In the fall, we had 54 cats from 26 households participate in a 12-week trial. Cats were divided into two groups, and the groups alternated wearing BCCs for two weeks followed by two weeks with no collar cover. This method insured against any differences across treatments due to weather or seasonal change over the course of the trial. During the “off” weeks, owners removed both the Birdsbesafe® collar and the interior quick-release collar so that the test was against fully collarless cats. All prey items were frozen, marked as coming from cats with or without collars, and identified to species by our research team. In the spring, another 12-week trial was run exactly as the first but with a subset of 19 cats from 10 households that participated in the fall study. The lower number reflects some owners wishing to not participate in a second trial, as well as owners away for the summer months.

The Australia study Hall et al. (2015) carried out two annual trials of cats wearing the BCC against collarless cats in Perth, Western Australia (32° S latitude). The first year’s trial ran for six weeks during austral spring and summer from October 2012 through February 2013, and the second year’s trial again ran for six weeks, from October 2013 through January 2014. The first trial involved 53 cats from 39 households over a period of six weeks. Half of the cat participants wore BCCs for the first three weeks, followed by three weeks without BCCs. The other half began with

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no BCCs for three weeks, followed by three weeks wearing the BCCs. Three different colors of the BCC were tested against each other. Analyses were done at the level of household so sample size in this year was 39 households. In the second year of testing, 61 cats from 43 households completed the trial, with the same division across two groups of cats over six weeks. Only the most effective color of BCC from year one was tested again in year two. The analyses were broken down across birds, mammals, and reptiles, as well as animals with good color vision (birds and reptiles) vs. those without (mammals).

RESULTS Because the New York and Australia trials were of different lengths, it is easiest to compare them if we examine the magnitude change across trials for each study when cats were wearing the BCC versus when they were collarless. In the spring New York trial, which lasted 12 weeks, cat predation on birds averaged 19 times higher when cats were not wearing the BCC. In fact, total spring bird predation with 19 cats over six weeks totaled only one bird when cats wore the BCC. In the fall, cat predation on birds was still significantly decreased, with cats killing 3.4 times more birds when not wearing BCCs (Figure 2). In Australia, the BCC was deemed most effective in year 1; the authors found that cats brought home 28% of total birds while wearing the BCC, while in year 2 they brought home 40% of birds in that same period with the BCC. Combined, cats brought home an average of 34% of bird prey while wearing the BCC. In summary, Australian cats reduced the number of birds brought home by an average of 1.5 to 2.5 times while wearing the BCC (Hall et al. 2015).

WHY THE DIFFERENCE IN EFFECTIVENESS OF THE BIRDSBESAFE® COLLAR COVER? The Australian trials were completed during the nesting season for “down under” birds. It is therefore a good comparison with the New York spring trial. If we assume that the BCC should work equally well for all birds at mitigating predation by cats, we would expect similar results in trials with robust sample sizes. The fact that they were not equal and that the New York trial was in fact almost eight times more successful at keeping cats from killing birds (in comparison to the average kill rate for each trial with no collar) supports my hypothesis for a link between avian physiology and conservation management. Studies by Hau and colleagues (Hau et al. 2010, Hau et al. 2008, Hau 2007, Wikelski et al. 2003) have examined the roles of the hormones corticosterone and testosterone in different life-history strategies of birds. Hau et al. (2010) predicted and found strong evidence that peak testosterone during the breeding season was higher in short-lived bird species with high courtship and breeding effort in comparison to longer-lived birds that display lower mating effort. The comparison used birds from a northern USA temperate site (42° N latitude) and tropical birds from the Republic of Panama (9° N latitude). The authors suggest that these hormones modulate life history responses to the environment with testosterone relating to

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mating success. Thus, short-lived, temperate passerine birds elevate testosterone levels higher in their short breeding season when there is an all-or-nothing approach to raising young. Since temperate passerine birds typically have adult annual survivorship rates of only 50% (Sillett and Holmes 2002), just one out of two adults will have another chance to breed again in the future. Therefore, temperate birds have evolved a life history that pushes for larger clutch size and more attentiveness at the nest when compared to tropical counterparts (Ghalambour and Martin 2001). So how does all of this relate to an anti-predator device like the Birdsbesafe® cat collar cover? Our north temperate birds act more like tropical and lower latitude birds only once they have completed breeding; they relax. Under this hypothesis, we would never expect the spectacular difference in effectiveness of the CC found in our New York study for lower latitude birds, because they are not as distracted by surging levels of testosterone. They are more vigilant and better at noticing cats creeping up on them, even in the breeding season. What this suggests for owners of cats in the Adirondack region, the northeastern United States, and really anywhere at higher latitudes is that these regions are the places where this anti-predator device will be most useful. Specifically, for owners who choose to use it, it is critical to use the device in the passerine breeding season from mid-spring through mid-summer. As northeast songbirds continue to decline due to a myriad of affronts including habitat alteration, climate change, window, building and wind-turbine strikes, as well as domestic cat predation, bird lovers who are also cat lovers with outside cats need to understand they have a responsibility to their backyard birds. Of course it is best to keep domestic cats inside (see American Bird Conservancy 2015), but if circumstances do not allow this, the Birdsbesafe® cat collar cover is a very effective alternative for decreasing songbird predation. Figure 1: The author’s cat models the Birdsbesafe® cat collar cover.

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Figure 2: Birdsbesafe® cat collar covers reduced the number of depredated birds recovered from individual cats by three to up to 19 times across two seasonal New York trials. Use of collar cover versus no collar was statistically significantly different each season (randomization test, p < 0.05). Figure displays each seasonal 12-week trial broken into the total time wearing versus not wearing collar cover (six week periods).

L I T E RAT U R E C I T E D

American Bird Conservancy, Cats Indoors campaign. Accessed August 2015 at http://www.abcbirds.org/abcprograms/policy/cats/index.html. Birdsbesafe® LLC. Accessed August 2015 at http://www.birdsbesafe.com. Chen, D.M., and T.H. Goldsmith. 1986. “Four spectral classes of cone in the retinas of birds,” Journal of Comparative Physiology A, 159: 473-479. Ghalambor, C.K. and T. Martin. 2001. “Fecundity-survival trade-offs and parental risktaking in birds,” Science, 292: 494-497. Goymann, W., I.T. Moore, A. Scheuerlein, K. Hirschenhauser, A. Grafen, and J.C. Wingfield. 2004. “Testosterone in tropical birds: Effects of environmental and social factors,” The American Naturalist, 164: 327-334. Hall, C.M., J.B. Fontaine, K.A. Bryant, and M.C. Calver. 2015. “Assessing the effectiveness of the Birdsbesafe® anti-predation collar cover in reducing predation on wildlife by pet cats in Western Australia,” Applied Animal Behaviour Science, in press.

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Hau, M., R.E. Ricklefs, M. Wikelski, K.A. Lee, and J.D. Brawn. 2010. “Corticosterone, testosterone, and life-history strategies of birds,” Proceedings Royal Society B, 277: 3203-3212. Hau, M., S.A. Gill, and W. Goymann. 2008. “Tropical field endocrinology: Ecology and evolution of testosterone concentrations in male birds,” General and Comparative Endocrinology, 157: 241-248. Hau, M. 2007. “Regulation of male traits by testosterone: implications for the evolution of vertebrate life histories,” Bioessays, 29: 133–144. Hill, G.E., and Hill, G.E., and K.J. McGraw, Eds. Bird Coloration, Vol. 2. 2006. Boston: Harvard University Press. Jacobs, G.H. 2009. “Evolution of colour vision in mammals,” Philosophical Transactions Royal Society of London B, Biological Sciences, 364(1531): 2957–2967. Loss, S.R., T. Will, and P.P. Marra. 2013. “The impact of free-ranging domestic cats on wildlife of the Unites States,” Nature Communications, 4: 1396. Martin, T.E., P.R. Martin, C.R. Olson, B.J. Heidinger, and J.J. Fontaine. 2000. “Parental care and clutch size in North and South American birds,” Science, 287: 1482-1485. Ricklefs, R.E., and Wikelski M. 2002. “The physiology/life history nexus,” Trends in Ecology and Evolution, 17: 462–468. Sherry, T., and R. Holmes. 1997. “American Redstart (Setophaga ruticilla),” (Online) The Birds of North America Online. Accessed August 2015 at http://bna.birds.cornell.edu/bna/species/277. Sillett, T.S., and R.T. Holmes. 2002. “Variation in survivorship of a migratory songbird throughout its annual cycle,” Journal of Animal Ecology, 71: 296–308. Stearns, S. C. 1992. The Evolution of Life Histories. Oxford, UK: Oxford University Press. Wikelski, M., M. Hau, W.D. Robinson, and J.C. Wingfield. 2003. “Reproductive seasonality of seven Neotropical passerine species,” The Condor, 105: 683-695. Willson, S.K., I. Okunlola, and J. Novak. 2015. “Birds be safe: Can a novel cat collar reduce avian mortality by domestic cats (Felis catus)?” Global Conservation and Ecology, 3: 359-366.

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NORTHERN NEW YORK AUDUBON: ORGANIZATIONAL PROFILE Supporting Avian Research, Discovery, and Enjoyment JOHN THAXTON

INTRODUCTION The abundance of avian species, relatively intact habitats, and opportunities to explore makes the Adirondack Mountains and the surrounding St. Lawrence and Champlain Valleys a birders’ paradise. For several decades, Northern New York Audubon (NYAA) has facilitated research and exploration in the greater Adirondack region. The goal of the organization is to conserve and restore natural ecosystems in the Adirondacks, focusing on birds, other wildlife, and their habitats for the benefit of humanity and the Earth’s biological diversity.

HISTORY AND ORGANIZATIONAL STRUCTURE Northern New York Audubon, a nonprofit corporation, began its existence as High Peaks Audubon Society, Inc. (HPAS) in 1978. HPAS was the initiative of Norman Mason, a retired Episcopalian priest. The organization initially had trouble gathering the thirty-five members required for a National Audubon Society (NAS) chapter but eventually achieved that threshold and incorporated as a 501(c)(3). The board meets six times per year and generates and reviews actions and policies by way of committee discussions, with a round table conversation about particular programs and/or events. The following committees consist of a chair and at least two other board members: Finance, Membership, Education, Field Trips, Publications, Publicity, and Conservation. Board Members serve on a volunteer basis. From the beginning, NNYA sought to emulate the National Audubon Society’s mission and to “engage in any such educational, scientific, investigative, literary, historical, philanthropic, and charitable pursuits as may be part of the stated purposes of the National Audubon Society, of which this Corporation shall function as a Chapter,” and as one of National

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Audubon Society’s 27 local chapters across New York, NNYA endeavors to “promote the protection and proper management of birds, other wildlife and their habitats through advocacy and education.” In 2008, HPAS merged with St. Lawrence/Adirondack Audubon (SLAA), another local chapter of National Audubon Society, to become NNYA. The boards of both HPAS and SLAA felt that a larger Audubon chapter, embracing significantly more territory in northern New York and a twofold increase in membership, would benefit both organizations as well as the memberships they served. The members at large agreed and handily exceeded the ten percent in favor votes needed to ratify the merger. For many years, John M.C. Peterson functioned as NNYA’s driving force, editing its newsletter for twenty-five years and developing and overseeing its two signature initiatives— the Four Brothers Island gull banding project and the Crown Point Bird Banding Station. When Peterson retired as editor of the newsletter in 2001, his two immediate successors published inconsistently or not at all. Joan Collins offered to try her hand at publishing the newsletter. Joan went to press every deadline for five years and then gave up editorship. She then moved to Potsdam and joined SLAA where she edited their newsletter. John Thaxton was appointed newsletter editor upon Joan’s departure and continues as editor of the NNYA newsletter.

ACTIVITIES Peterson, on behalf of NNYA, entered into a contract with The Nature Conservancy/ Adirondack Land Trust to manage Four Brothers Islands, a group of four islands in Lake Champlain approximately two miles offshore from Willsboro, NY. Over the next ten years, a group visited the islands annually and banded a thousand gulls per annum. Most were Ring-billed Gulls (Larus delawarensis) but quite a few were Herring Gulls (Larus argentatus) and Great Black-backed Gulls (Larus marinus) as well. The annual banding on Four Brothers attracted many volunteers and amounted to a major educational and environmental experience for many attendees. Over the course of ten years the Four Brothers Islands program banded 25,352 individual birds of 12 species with some birds recovered as far afield as the Azores, Ireland, and Spain. On one occasion, the group encountered sixteen dead Double-Crested Cormorants (Phalacrocorax auritus) arranged in a tight pattern among dozens of .22-caliber shell casings and 20-gauge shotgun shells. It made for a powerful environmental statement, which was not lost on the young volunteers. Peterson also started the Crown Point Bird Banding Station on the western shore of Lake Champlain. The site, a peninsula extending into the lake and a natural site for migrating birds, is part of the Crown Point Bird Conservation Area located on the state historic site. The banding station was linked to NNYA for many years and celebrated its fortieth

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consecutive year of operation in 2015. From 1976-2015 the station banded 18,604 individual birds of 106 species (including 28 warblers) and has hosted thousands of visitors, ranging from school groups to prisoners from the Moriah Shock Incarceration Correctional Facility in Essex County, NY. It represents a major environmental/educational initiative and operates entirely on a volunteer basis. The station separated from HPAS in 2004 when the Crown Point Bird Banding Association formed. Peterson’s tenure as newsletter editor lasted for twenty-five years, during which he held forth with inexorable regularity on all things Adirondack, especially birds; his efforts won accolades from NAS, which named the newsletter the Best National Audubon Society Chapter Newsletter of the Year and which flew Peterson to Colorado to receive an award. Peterson also served as the Region 7—Adirondack/Champlain editor of The Kingbird, the journal of the New York State Ornithological Association. For 26 years he kept track of avian sightings throughout the Adirondacks and submitting detailed reports quarterly. Under the aegis of HPAS, Peterson also served as regional coordinator for the Atlas of Breeding Birds in New York State and the Second Atlas of Breeding Birds in New York State, a monumental task that he performed twice. In 2003, board member Brian McAllister conceived of the Great Adirondack Birding Celebration, a three-day festival featuring field trips, workshops, lectures, and other activities that HPAS organized with the staff of the Paul Smith’s Visitor Interpretive Center. The celebration has taken place every year since and has attracted visitors from all over the United States and Canada hoping to see iconic Adirondack boreal bird species such as the Boreal Chickadee, Gray Jay and Black-backed Woodpecker. Other birds of interest are the region’s signature northern-breeding birds such as Yellow-bellied Flycatcher, Blackpoll Warbler, and Bicknell’s Thrush. Bicknell’s Thrush nests above thirty-seven hundred feet (the Bicknell’s breeds only in New York, New Hampshire, Vermont, Maine, Quebec, and the Maritime Provinces). The celebration’s keynote speakers have included birding luminaries such as Dr. Frank Gill, Lang Elliott, Dr. Bridgette Stutchberry, Dr. Peter Mara, Scott Weidensaul, Dr. Sara K. Morris, Noah Stryker, and Richard Crossley. NNYA continues to support the celebration by offering an honorarium to the keynote speaker and its members lead many of the field trips. Only three summits in the northeast are accessible by car: Whiteface Mountain in the Adirondacks, Mt. Washington in New Hampshire, and Mt. Mansfield (gondola access) in Vermont. The celebration offers two trips up Whiteface to see these special montane birds before the highway opens to the general public. These trips always fill to capacity. In 2005, the Hamilton County Bureau of Tourism started the Adirondack Birding Festival, which consists of field trips, lectures, and a dinner cruise. The bureau reached out to HPAS board members for help in designing and leading the field trips. Joan Collins played an

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instrumental role in planning the festival and asked John and Pat Thaxton for help in leading the field trips. Collins and the Thaxtons have led field trips every year of the festival, and Joan and John have delivered lectures at several festivals. Hamilton County designed the festival to take place the weekend after the celebration with the hope that attendees will stay in the Adirondacks for both occasions and positively impact the regional pre-summer economy. NNYA sponsors and promotes six Audubon Christmas Bird Counts (CBC) and devotes considerable newsletter space to documenting the results. The CBCs attract sizable groups of birders, from the expert to the clueless. Most birders have a warm and lively CBC Count Dinner, during which a compiler puts together a list of all species and the number of each observed. The CBC results must comply with NAS criteria and are entered into the main CBC database. CBCs in the Adirondacks have revealed a steady increase in the numbers and varieties of several species traditionally found only further south in winter, such as Red-bellied Woodpecker (Melanerpes carolinus) and Carolina Wren (Thryothorus ludovicianus). NNYA members participate in the following CBCs: Elizabethtown (NY), Ferrisburgh (VT/ NY), Massena (NY), Plattsburgh (NY), Potsdam-Canton (NY), and Saranac Lake (NY). (To learn more about the Saranac Lake CBC, see Master this issue.) In 2007, the Joseph and Joan Cullman Conservation Foundation gave a ten thousand dollars grant to fund the organization’s conservation and education initiatives. After much discussion, the board decided to give away all of the grant money rather than to put half of it in the bank. For the past nine year since, the Cullman Foundation has given HPAS/ NNYA ten thousand dollars or more per year. HPAS/NNYA has partly or fully funded include staff positions, research, and education/ outreach programs such as:

Research topics: White-crowned Sparrows on Cranberry Lake Bicknell’s thrush and other high-elevation boreal birds Monitoring Avian Productivity and Survivorship at the Smitty Creek Bird Banding Station Effects of acid deposition on songbird populations Two studies of Rusty Blackbirds (Euphagus carolinus) (see McNulty et al. this issue) Bird population trends at Spring Pond Bog The Spruce Grouse (Falcipennis canadensis) Management Plan Bird point counts at Shingle Shanty Preserve and Research Station DNA sequencing of Bicknell’s Thrush via the nucleotides of mitochondrial ND2

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The effects of exurban sprawl on Ovenbirds (Seiurus aurocapilla) G olden-winged Warblers (Vermivora chrysoptera) at the Indian River Preserve S oundscapes in Adirondack peatlands

Monitoring and outreach: N ets for the Crown Point Bird Banding Station T he All Taxa Biodiversity Inventory T he Living Bird Exhibit by the SUNY ESF Northern Forest Institute P roject Silkmoth, an effort to map and monitor giant moths P ublication of The State of the Adirondack Boreal, Part 1: Composition and Geography and Part 2: Changes and Threats by Jerry Jenkins D evelopment of two new routes for Mountain Birdwatch.

Interns for organizations: W ildlife Conservation Society’s (WCS) Boreal Bird Initiative Biodiversity Research Institute’s Adirondack Loon Conservation Project (see Schoch this issue) T he Wild Center In 2010, Malone resident Nancy Smith Collins and her family gave NNYA a bequest of fifty thousand dollars to use as the organization saw fit. The board decided to invest the money in the Adirondack Community Trust and to spend it down over the course of ten years. The hope is to award five thousand dollars grants for eleven years. Some of the funded projects include: B ird-friendly Hayfields as Refugia for North Country Grassland Birds A vian Biodiversity Indicators to Diagnose the Health of Estuarine Wetlands in the Massena Great Lakes Area of Concern R ed-headed Woodpecker Breeding Ecology and Nest-site Selection at the Northern Limit of its Distributional Range R ecurring Bird Surveys in Lowland Boreal Habitat at Shingle Shanty Preserve and Research Station T he American Kestrel Project I nitiation of a Monitoring Program for Climate Change Adaptation: Fixed Radius Bird Surveys at Intervale Lowland Funds to construct a High School Phenology Trail at National Sports Academy in Lake Placid.

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A third resource NNYA manages is the Rutkowski Fund, an endowment of two thousand dollars donated by David and Catherine Rutkowski in memory of their son. The NNYA uses the interest to partially cover the cost of sending a child to one of the New York State Department of Environmental Conservation summer camps. The fund has almost tripled in value over the past twenty years. Since 2010, NNYA has sent either a board member or a teacher from the area to NASâ&#x20AC;&#x2122;s Hog Island, an educational summer camp on an island off the coast of Bremen, Maine. The camp offers a week-long program for Audubon leaders and another one for environmental educators. The board members and teachers who have participated in the programs have described them with lavish praise. HPAS published has two books, Birds of Essex County by Geoffrey Carleton (1976, edited by Peterson) and Birds of Clinton County by Charles W. Mitchell and William E. Krueger (1997, edited by Thaxton). Both books are available for sale on the NNYA website. To learn more about membership, field trips, and research and conservation projects, visit www.NNYA.org.

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BIODIVERSITY RESEARCH INSTITUTE: Songbird Research from Sphagnum Bog to Alpine Summit AMY K. SAUER AND DAVID C. EVERS

276 Canco Road, Portland, Maine 04103 Office: 207-839-7600 ext. 145 amy.sauer@briloon.org Amy Sauer is the Songbird Program Director for Biodiversity Research Institute and a Ph.D. Candidate at Syracuse University. David Evers is the Chief Scientist and Executive Director for Biodiversity Research Institute.

Population declines of migratory songbird species throughout their range are well documented and have been associated with a complex variety of stressors, including, but not limited to: environmental pollution; habitat loss, conversion, and fragmentation; energy development and generation; and climate change. To better understand these and other potential impacts on songbird populations, biologists from Biodiversity Research Institute (BRI) collect scientific data to address these stressors through studies that target mercury exposure and effects assessments, determine movement and distribution patterns, and integrate findings with conservation and management strategies. Through an emphasis on neotropical migrant species, BRI has conducted research at various locations within the United States, particularly the northeastern U.S., as well as study sites in Central and South America, the Caribbean Islands, and China. With an overarching approach centered on the assessment of environmental stressors on wildlife health, BRI songbird studies are designed to advance scientific knowledge and to contribute valuable data to inform policy, assist in management decisions, and establish conservation initiatives for local, regional, and global songbird populations.

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MERCURY CONTAMINATION & WILDLIFE HEALTH Mercury (Hg) contamination in aquatic and terrestrial ecosystems is increasingly recognized as a widespread issue that poses considerable reproductive, behavioral, and physiological risks to wildlife populations. As a global pollutant that enters ecosystems from both local and distant emission sources, such as coal-fired power plants, mercury is released into the atmosphere and deposited upon the landscape in an inorganic, biologically unavailable state. Micro-organisms, primarily residing within the soils, then convert inorganic mercury to an organic form, methylmercury (MeHg), which is highly toxic and which has the ability to be transferred through food webs and biomagnify within species positioned at high trophic levels, such as songbirds. Designated by the U.S. Environmental Protection Agency as a Persistent, Bioaccumulative, and Toxic (PBT) pollutant, methylmercury has become a globally-recognized conservation concern due to its ability to biomagnify and bioaccumulate within the environment and cause adverse health effects to wildlife and people. To date, most studies about mercury in wildlife have focused on top-predator, fish-eating birds, such as the Common Loon, because methylmercury biomagnifies and bioaccumulates to high levels within their tissues (see Schoch this issue). However, research has demonstrated that songbirds foraging on prey with an aquatic food web base can also bioaccumulate methylmercury at concentrations similar to or greater than fish-eating birds. Songbirds inhabiting upland forests not associated with aquatic environments have also been found to exhibit elevated body burdens, particularly high-elevation boreal species (see Glennon and Seewagen in this issue). Additionally, numerous toxicology studies have documented that songbirds are sensitive and susceptible to the multi-systemic effects of methylmercury, including: endocrine and immune system disruption, skewed sex ratios, altered songs, reproductive impairment, asymmetrical feather growth, reduced body condition, and decreased survival rates. Therefore, BRI has developed a number of regional studies to better quantify baseline exposure levels and to assess the impacts of atmospheric mercury deposition within a wide range of songbird species and habitat types. By utilizing songbirds as indicators of ecosystem mercury contamination, this research will improve our abilities to more accurately define and monitor levels of methylmercury bioavailability across the landscape, which is crucial to evaluate the risk this PBT poses to regional songbird communities. In the northeastern United States, a region widely impacted by atmospheric mercury deposition, BRI biologists have conducted intensive field studies focusing on the exposure levels and adverse health effects of methylmercury on resident and migratory songbird populations. The North Woods provide essential habitat for a variety of songbird species of conservation concern from wetland-obligate, Rusty Blackbirds (Euphagus carolinus; see McNulty et al. this issue), to high-elevation specialist, Bicknellâ&#x20AC;&#x2122;s Thrush (Catharus bicknelli). Unfortunately, environmental conditions in the Northeast, such as elevated mercury

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deposition rates, thin soils, abundant wetlands, and highly acidic habitats, which are pervasive in the Adirondack Park, create a combination of factors ideal for efficiently converting atmospherically deposited mercury into the toxic and bioavailable form, methylmercury. Consequently, research has designated portions of the Adirondack Park as a â&#x20AC;&#x153;biological mercury hotspot,â&#x20AC;? which is defined as an area that is subject to high mercury deposition rates and possesses landscape characteristics that promote the uptake of methylmercury into aquatic and terrestrial food webs. Overall, the relatively intact ecosystems of the Adirondack Park serve a significant role as a vital and important area for the conservation of boreal songbird species. BRI research conducted at study sites in the Adirondack Park is designed to further understand the complexities and dynamics associated with the biomagnification and bioaccumulation of methylmercury through food webs as a means to protect its wildlife species from the detrimental impacts of mercury contamination.

BRI PROJECT METHODOLOGIES AND RESEARCH RESULTS To assess methylmercury concentrations in songbird communities at the landscape level, BRI field biologists use standard methodologies for collecting data and samples at each study site. Sampling generally occurs during the months of June and July, which correlates with periods of peak breeding activity for Northeast songbird species. Insectivorous songbirds are captured using non-lethal, mist-netting techniques, which includes decoys and playback calls to encourage a territorial response. During processing, each bird is banded, weighed, morphological measurements are recorded, blood and feather samples are collected for mercury and isotope analysis, and individuals are released back into their territories. Each songbird is fitted with an aluminum U.S. Geological Survey (USGS) leg band that contains a unique number, and these records are submitted to the USGS Patuxent Wildlife Research Center for use in the North American Bird Banding Program. Songbirds are banded during processing as a means to identify individual birds during future on-site captures or if found at another location during its life history. If captured again, the band serves as an individual record of its history and may yield information related to life span, dispersal and migratory patterns, and wintering or breeding site fidelity. To determine individual mercury concentrations, songbird blood samples are collected using sterile collection techniques and are reflective of recent dietary uptake of methylmercury, thereby representing available methylmercury levels in a particular area, such as a breeding territory. In contrast, feather samples represent long-term mercury exposure and are indicative of methylmercury body burdens over the birdâ&#x20AC;&#x2122;s lifetime, as well as dietary uptake during periods of feather molt. To date, BRI biologists have captured, sampled, and analyzed data from over 11,000 songbirds across a wide variety of habitats and species in 37 states. In the Adirondack Park, 948 songbirds from 41 species have been captured from 2006-2015. In total, 916 blood and feather samples have been analyzed to examine mercury concentrations among songbirds that represent many habitat types on a mix of public and private Adirondack lands. Overall

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findings have indicated that wetland songbirds are at the greatest risk to the impacts of mercury contamination, particularly those species that primarily consume insects during the breeding season, which include Adirondack Park songbirds such as: Olive-sided Flycatcher (Contopus cooperi), Carolina and Marsh Wrens (Thryothorus ludovicianus and Cistothorus palustris), Lincolnâ&#x20AC;&#x2122;s Sparrow (Melospiza lincolnii), Northern and Louisiana Waterthrushes (Parkesia noveboracensis and P. motacilla), Palm and Canada Warblers (Setophaga palmarum and Cardellina canadensis), and Rusty Blackbirds. The BRI database provides critical information relating to regional species sensitivity, in addition to geographic locations and specific habitats of concern, and provides a foundation to direct future research initiatives.

REGIONAL SONGBIRD PROJECTS Beginning in 1999, BRI biologists initiated research at study sites across the northeastern United States to identify at-risk songbird species, classify sensitive habitat types, and assess the impacts of mercury deposition within a variety of ecosystems. Based on the results of this large-scale research effort and the clear need to further characterize the impacts of mercury contamination on wildlife populations, BRI and The Nature Conservancy began a five-year project in 2013, sponsored by the New York State Energy and Research Development Authority (NYSERDA), to monitor mercury concentrations in New York State songbird communities. To evaluate how environmental mercury loads are changing over time in New York, songbirds are sampled on an annual basis at established long-term research sites within the Adirondack Park, Catskill Mountains, and Long Island. Within each of these areas, songbirds are targeted in a number of diverse habitats, ranging from forested cover types to highly-acidic sphagnum bogs, to model and project the effects of habitat type on methylmercury availability and uptake by songbirds inhabiting those locations. Data from these annual monitoring sites are supplemented with survey efforts from other regions in New York State that have been prioritized as sensitive sites or regions with limited songbird mercury data, as a means to fill in existing information gaps and aid in the identification of additional biological mercury hotspots. The overall goals of this long-term project are to further quantify and monitor songbird mercury concentrations across a diverse range of habitat types, and effectively assess the impacts of recent changes in mercury emissions policies on wildlife and ecological health across New York State (e.g., the newly instituted Mercury and Air Toxics Standards Rule) (USEPA, 2011). Utilizing mercury and stable isotope technology, BRI initiated a two-year study in 2015, funded through a research grant by the Northeastern States Research Cooperative (NSRC), to identify the primary source types of mercury being deposited in Adirondack ecosystems. This research builds upon a similar study, led by BRI in 2014, which examined mercury isotope signatures in songbird samples from tidal marsh and pine barren habitats on Long Island and sphagnum bogs and upland forests in the Adirondack Park, in order to identify and differentiate atmospheric mercury source types within each region. To expand upon this initial study and further investigate the sources of atmospheric mercury deposition

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within Adirondack food webs, BRI biologists began an intensive survey in 2015 at three long-term study sites by collecting samples, which include: precipitation, soils, invertebrates (prey items), and songbird blood and feathers. An overall synthesis of these research efforts will allow scientists to advance understanding of the major sources of regional atmospheric mercury in the Adirondack Park and contribute a greater working knowledge for policy initiatives designed to control and reduce mercury emissions. As part of a collaboration between Syracuse University and BRI, and funded through a NYSERDA Environmental Monitoring, Evaluation, and Protection (EMEP) Graduate Fellowship and NSRC Graduate Research Grant, a dissertation project was conducted to identify pathways of methylmercury bioaccumulation in terrestrial habitats at several sphagnum bog, hardwood forest, and high-elevation boreal systems in the Adirondack Park. This project was designed to build upon the results of regional songbird mercury research established by BRI (Evers and Lambert, 2005) and Chris Rimmer (Rimmer et al., 2005, 2010), which identified sphagnum bog and montane forests as sensitive habitats where elevated songbird blood mercury concentrations had been documented. All study sites were intensively sampled multiple times during the breeding season, and samples were representative of the various compartments within the associated food webs, including: soils, leaf litter, fresh vegetation, forest-floor invertebrates, and songbird blood and feathers. Collected samples were analyzed for methylmercury, total mercury and stable isotope signatures to better define methylmercury biomagnification and trophic connectivity among songbirds and their prey items within Adirondack Park food webs. These data will be utilized to complement ongoing research projects and provide much-needed information on the connections between mercury deposition and terrestrial ecosystems in the Adirondack Park. In an effort to link year-round mercury exposure for neotropical songbird species between their Northeast breeding grounds and tropical wintering areas, BRI has established the Neotropical Connections Mercury Network. This initiative examines songbird mercury concentrations at multiple wintering areas to better define the impacts of mercury deposition in tropical ecosystems and lifetime methylmercury exposure for some species. Such investigations are especially critical now because of the dramatic increase in artisanal smallscale gold mining in Latin America, an activity which often uses high amounts of mercury to amalgamate gold particles. Since 2007, BRI has banded 938 songbirds at 34 study sites within six Latin American countries (Belize, Costa Rica, Mexico, Nicaragua, Panama, and Puerto Rico). Of this total, 867 blood and feather samples have been analyzed for mercury concentrations from 162 tropical species. For long-distance migrant songbirds, like the Northern Waterthrush, which winter and breed within wetland habitats that often have elevated methylmercury production, elevated mercury exposure is occurring year-round. Therefore, data from this BRI project will aid assessment of the physiological impacts of mercury on long-distance migrants that overwinter in the tropics. It is anticipated that data will also be collected to link current research endeavors with long-term banding stations

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(e.g., Monitoreo de Sobrevivencia Invernal/Monitoring Overwintering Survival [MoSI] networks), other avian conservation efforts (e.g., Partners in Flight Program with Cornell Lab of Ornithology), and protected reserves (e.g., Runaway Creek Nature Reserve in Belize). Ultimately, this information will be developed into a regional map of biological mercury hotspots that can be used by scientists and policy makers to significantly improve an understanding of the ecological connections between mercury deposition and wildlife health in tropical ecosystems. Such information will be critical for monitoring the changes of environmental mercury loads after the new global mercury treaty, the Minamata Convention, goes into effect (i.e., projected around mid-2016)(UNEP, 2015).

FUTURE DIRECTIONS Global mercury emissions have increased dramatically since the onset of the industrial age, a trend that has been observed using museum specimens of seabirds. However, the trend in mercury exposure for terrestrial birds has been largely unexplored, particularly within wetland breeding songbird species that are experiencing population declines and that exhibit high mercury concentrations in the Northeast. Beginning in the fall of 2015, BRI will begin working with the Harvard Museum of Natural History and the Harvard School of Public Health in Boston, and the American Museum of Natural History in New York City to analyze archived museum songbird specimens for historical patterns and trends in mercury exposure. Several wetland songbirds have been selected and include species that breed in the Adirondack Park, such as: Olive-sided Flycatcher, Palm Warbler, and Rusty Blackbird. Data from this study will track changes in songbird methylmercury body burdens prior to industrialization (i.e., the late 1800s) for comparison with current feather concentrations from wetland breeding birds in New York State. As Northeast bogs are generally considered to be hotspots for mercury methylation and subsequent locations for high-mercury songbirds, BRI began a collaborative effort with the Smithsonian Institute in 2015, at locations in Maine and New Hampshire, to determine the extent to which mercury may be playing a role in the widespread decline of the Olive-sided Flycatcher. Currently listed by the NYS Department of Environmental Conservation as a High-Priority Species of Greatest Conservation Need, Olive-sided Flycatcher population levels have declined in the Northeast at alarming rates. Limited data exist on the mercury body burden of this species, and the sampling of adults for blood and feathers will allow researchers to infer information about methylmercury uptake on their breeding and wintering grounds. Geolocators, lightweight tracking devices used to record songbird movement, will also be non-invasively attached to adults to document year-round habitat utilization and migratory patterns. This work is affiliated with research being conducted across North America by the Olive-sided Flycatcher Working Group and will begin in the Adirondacks during the summer of 2016.

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In summary, songbirds are now recognized as critical indicators of mercury in terrestrial ecosystems due to the ability of insectivore food webs to biomagnify methylmercury to levels that can adversely impact physiological health, behavior, reproductive success, and survival rates across a wide variety of species and habitats. Research projects conducted by the Songbird Program of Biodiversity Research Institute contribute scientific data that are critical to improve understanding of the complex and dynamic connections among methylmercury availability, environmental factors, and the ecology of songbird species in an effort to inform policy initiatives and conservation efforts that aim to reduce the impacts of mercury contamination on wildlife health. L I TE R AT U R E C I T E D

Adams, E., A. Sauer, O. Lane, J. Blum, M. Tsui, L. Sherman, and D. Evers. 2014. “Mercury stable isotope analysis in Long Island and Adirondack songbirds,” New York Energy Research and Development Authority EMEP Program Final Report, 14-31. Available at www.nyserda.org. Edmonds, S.T., D.C. Evers, N.J. O’Driscoll, C. Mettke-Hoffman, L. Powell, D. Cristol, A.J.McGann, J.W. Armiger, O. Lane, D.F. Tessler, and P. Newell. 2010. “Geographic and seasonal variation in mercury exposure of the declining Rusty Blackbird,” The Condor, 112:789-799. Edmonds, S., N. O’Driscoll, N. Hillier, J. Atwood, and D.C. Evers. 2012. “Factors regulating the bioavailability of methylmercury to breeding Rusty Blackbirds in northeastern wetlands,” Environmental Pollution, 171: 148:154. Evers D. and K. Lambert. 2005. Northeastern mercury connections: the extent and effects of mercury pollution in northeastern North America. Biodiversity Research Institute, Portland, ME. BRI ID# 2005-17, pp 28. Evers, D.C., Y.J. Han, C.T. Driscoll, N.C. Kamman, M.W. Goodale, K.F. Lambert, T.M. Holsen, C.Y. Chen, T.A. Clair, and T. Butler. 2007. “Identification and evaluation of biological hotspots of mercury in the northeastern U.S. and eastern Canada,” Bioscience, 57:29-43. Evers D., A. Jackson, T. Tear, and C. Osborne. 2012. Hidden Risk: Mercury in terrestrial ecosystems of the Northeast. Biodiversity Research Institute, Portland, ME. BRI ID# 2012-07, pp 33. Evers, D.C. and D.G. Buck. 2015. Center for Mercury Studies. Biodiversity Research Institute. Portland, Maine. BRI Science Communications Series BRI-2015-16. 36 pp.

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Jackson A., D. Evers, M. Etterson, A. Condon, S. Folsom, J. Detweiler, J. Schmerfeld, and D. Cristol. 2011. “Mercury exposure affects the reproductive success of a free-living terrestrial songbird, the Carolina Wren (Thryothorus ludovicianus),” The Auk, 128:759-69. Jackson A., D. Evers, E. Adams, D. Cristol, C. Eagles-Smith, S. Edmonds, C. Gray, B. Hoskins, O. Lane, A. Sauer, and T. Tear. 2015. “Songbirds as sentinels of mercury in terrestrial habitats of eastern North America,” Ecotoxicology, 24:453-467. Lane O., K. O’Brien, D. Evers, T. Hodgman, A. Major, N. Pau, M. Ducey, R. Taylor, and D. Perry. 2011. “Mercury in breeding saltmarsh sparrows (Ammodramus caudacutus caudacutus),” Ecotoxicology, 20:1984-1991. Rimmer C.C., McFarland K.P., Evers D.C., Miller E.K., Aubry Y., Busby D., Taylor R.J. 2005. “Mercury concentrations in Bicknell’s thrush and other insectivorous passerines in montane forests of northeastern North America,” Ecotoxicology, 14:223–40. Rimmer C.C., Miller E.K., McFarland K.P., Taylor R.J., Faccio S.D. 2010. “Mercury bioaccumulation and trophic transfer in the terrestrial food web of a montane forest,” Ecotoxicology, 19:697–709. doi: 10.1007/s10646-009-0443-x. United Nations Environment Programme (UNEP). 2015. “Minamata Convention on Mercury.” United States Environmental Protection Agency (USEPA). 2011. “Mercury and Air Toxics Standards (MATS) for Power Plants.” BRI’s mission is to assess emerging threats to wildlife and ecosystems through collaborative research, and to use scientific findings to advance environmental awareness and inform decision makers. For more information on the songbird projects and wildlife research conducted by Biodiversity Research Institute, please visit: www.briloon.org. Additional information on the research conducted by Biodiversity Research Institute is also available through the BRI Multimedia Library, which provides a publically-accessible resource and on-line opportunity for BRI staff to distribute their research results and share their project findings through scientific journal articles, research reports, books, news articles, and videos: www.briloon.org/multimedia-library/bri-library.

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CONSERVATION STATUS AND MONITORING OF BICKNELL’S THRUSH IN THE ADIRONDACKS AND NEW ENGLAND: A Brief Review MICHALE J. GLENNON 1 AND CHAD L. SEEWAGEN 1,2

1. Wildlife Conservation Society Adirondack Program, 132 Bloomingdale Avenue, Saranac Lake, NY 12983; ph: 518-891-8872, mglennon@wcs.org 2. AKRF Inc., 34 South Broadway, White Plains, NY 10601

ABSTRACT Bicknell’s thrush is among the most rare and probably most threatened species in North America and is considered the Nearctic-Neotropical migrant of highest conservation priority in the Northeast. The species breeds in high elevation spruce-fir forests in the northeastern US and Canada and is adapted to naturally disturbed habitats impacted by montane processes such as wind throw and fir waves. The U.S. Fish and Wildlife Service has recently issued a finding that the Bicknell’s thrush may warrant listing as threatened or endangered under the Endangered Species Act. The challenges facing Bicknell’s thrush are many, and New York State has a significant role to play in helping to safeguard the future of the species in the region. We provide a brief summary of regional monitoring and research efforts, what has been learned from them, and suggestions that may enhance the conservation of the species here and elsewhere. KEYWORDS:

Adirondack Park, Bicknell’s thrush, climate change, montane

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INTRODUCTION Bicknell’s thrush (Catharus bicknelli) is a species of great interest in the northeastern United States, both for birders and scientists alike. It breeds in high elevation conifer forests, primarily above 900 m, on mountaintops from the Catskills in New York State, through Maine, and into southern Canada. It is among the most rare and probably most threatened species in North America, and is considered the Nearctic-Neotropical migrant of highest conservation priority in the Northeast (Rimmer et al. 2015). In August of 2012, the U.S. Fish and Wildlife Service issued a finding that the Bicknell’s thrush may warrant listing as threatened or endangered under the Endangered Species Act of 1973; the proposal remains under review. Bicknell’s thrush habitat in the U.S. consists of montane forests dominated by balsam fir (Abies balsamea), with lesser amounts of red (Picea rubens) and black spruce (Picea mariana), white birch (Betula papyrifera), mountain ash (Sorbus americana), and other hardwood species (Rimmer 2008). It is adapted to naturally disturbed habitats and historically probably sought out patches of regenerating forest caused by fir waves, wind throw, ice and snow damage, fire, and insect outbreaks, as well as the chronically disturbed stunted conifer forests found at high elevations in the northeast. Highest densities of the species are often found in continually disturbed (high winds, heavy winter ice accumulation) stands of dense, stunted fir on exposed ridgelines or along edges of human-created openings, or in regenerating fir waves (Rimmer et al. 2015). A significant proportion of the global population is believed to breed in the U.S., with large areas of its montane breeding habitat found in NH, ME, NY, and VT (Lambert et al. 2005). Bicknell’s thrush wintering habitat is even more restricted than its breeding habitat and limited to only four islands in the Greater Antilles—Hispaniola, Cuba, Jamaica, and Puerto Rico. On its wintering grounds, Bicknell’s thrush prefers mesic to wet broadleaf montane forest. Large-scale loss and degradation of wintering habitat poses the greatest threat to the long-term viability of this species (Rimmer et al. 2015). Bicknell’s thrush is not well-sampled by traditional bird monitoring methods due to its uncommon polygynandrous mating system and preference for high elevation, dense habitat that can be difficult to access (Rimmer et al. 1996). Both males and females mate with multiple partners, multiple paternity is common, and more than one male often feeds nestlings at a given nest. Estimates of breeding densities for the species are therefore unreliable at best (Rimmer et al. 2015), but Bicknell’s thrush is nevertheless widely considered to be vulnerable to extinction and has been listed as such on the Red List of Threatened Species by the World Conservation Union since 2000. As a habitat specialist of high elevation conifer forests, it is susceptible to a number of threats on the breeding grounds, including pollution (e.g., acid rain, mercury), recreational development, cell tower construction, wind power development, and climate change (Rimmer et al. 2015).

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The objective of this paper is to describe research and monitoring efforts focused on Bicknell’s thrush in the Northeast and what we have learned from them. The majority of the research on Bicknell’s thrush in the Adirondack Park has been conducted by the Wildlife Conservation Society (WCS) on Whiteface Mountain. Research in the rest of the region has been driven primarily by the efforts of the Vermont Center for Ecostudies (VCE), which is also responsible for much of what is known about the ecology of Bicknell’s thrush on its wintering grounds (e.g., Atwood et al. 1996, Goetz et al. 2003, Strong et al. 2004, McFarland et al. 2013).

ADIRONDACK WORK The WCS Adirondack Program has been involved with research on Bicknell’s thrush on Whiteface Mountain (hereafter “Whiteface”) since 2004. Whiteface is located in the High Peaks region of the Adirondacks and contains approximately 1,020 acres of suitable Bicknell’s thrush breeding habitat (WCS, unpublished data). The mountain is characterized by spruce-fir forest at high elevations which then transitions into a mix of softwood and hardwood species, including paper birch and red maple (Acer rubrum) at lower elevations. It is a major destination for skiers in the northeast during the winter but in the summer months also hosts large numbers of visitors, who take advantage of the activities offered on the mountain, which include a scenic gondola, downhill mountain biking, 4x4 alpine expeditions, yoga, disk golf, nature trekking, and an adventure park. Because the mountain is accessible via the Veteran’s Memorial Highway, Whiteface also hosts bike races, an uphill footrace, and untold numbers of birders every summer season in search of easy access to famously inhospitable Bicknell’s thrush habitat. Several major changes have been made to the natural habitat and/or infrastructure on the mountain during the last 10 years. WCS has been involved in projects to try to determine the potential impact of these activities on Bicknell’s thrush occurrence.

Ski Trail Expansion The Olympic Regional Development Authority (ORDA), which manages Whiteface Mountain, submitted a proposed amendment to their Unit Management Plan to the Adirondack Park Agency in winter 2003/2004 outlining an expansion of existing ski trails on the mountain. WCS was contracted by ORDA beginning in 2004 to assess pre- and post-construction occurrences of Bicknell’s thrush and four other montane species that regularly occur on Whiteface, including blackpoll warbler (Setophaga striata), Swainson’s thrush (Catharus ustulatus), winter wren (Troglodytes hiemalis), and white-throated sparrow (Zonotrichia albicollis). These are high elevation target species that have been monitored annually since 2000 by the Mountain Birdwatch program of the Vermont Center for Ecostudies (Scarl 2013). WCS took the opportunity of working on the mountain to assess presence/absence of these species on other portions of the ski area as well as in the proposed ski trail expansion area and a nearby control, to determine how these species made use of available habitat on

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the mountain, and, in part, to compare their results with findings from similar research that had been conducted on Stratton and Mansfield Mountains in Vermont by Rimmer et al. (2004). Sampling points were established in five different treatment types: (1) existing glades (n=1), (2) proposed glades (n=3), (3) existing trails (n=4), (4) proposed ski trail expansion area (n=5), and (5) control areas (n=14) for a total of 27 sample points. Configuration of habitat on the mountain resulted in small sample sizes within several of the treatment types (i.e., existing glades, proposed glades, existing trails). A standard 10 minute point count method (Ralph et al. 1995) was used, allowing for future calculations of density given adequate numbers, but requiring only that birds are recorded as being within or beyond 50 m of the search point. This point count method enables the determination of presence/ absence as well as relative abundance among different site on the mountain. Timing of trail construction was delayed on the mountain, and WCS continued to partner with ORDA to monitor Bicknell’s thrush and other species, totaling four years of pre- and three years of post-construction surveys. Numbers of detections of all species were far below minimal standards required for calculating densities by distance sampling. In lieu of densities, we calculated relative abundances for Bicknell’s thrush and the four other montane bird species. We used analysis of variance (ANOVA; Zar 1999) to test whether there were differences in the total number of individual birds, the total number of species, the total number of Mountain Birdwatch species, and the abundance of individual species among the treatment types. Analysis of data from 2006-2010 revealed no statistical difference in occurrence of any of the target species over time or among areas surveyed (Figure 1). Lumping of surveyed areas into those with and without a trail of any type similarly revealed no difference in the occurrence of target species in areas with and without trails except white-throated sparrow, which had higher occurrence in trail areas. In direct comparisons of pre- and post-construction abundance of target species, only winter wren and white-throated sparrow responded significantly, exhibiting higher relative abundance post-construction in the newly constructed trail area. Bicknell’s thrush was the only species for which abundance declined in the new trail post-construction, but these declines were not statistically significant (Figure 2).

Helicopter Training In addition to its role as a major recreational destination in both summer and winter, Whiteface is an attractive location for training soldiers from nearby Fort Drum in high elevation helicopter landings. WCS was contracted by the U.S. Department of the Army to assess the occurrence of Bicknell’s thrush and other migratory bird species on Whiteface, specifically in the vicinity of the area used for the purpose of high-altitude helicopter flight training by the 10th Mountain Division Combat Aviation Brigade (CAB) through a maneuver license agreement with the State of New York, acting by and through ORDA. The monitoring of these species is a Class 1 National Environmental Policy Act compliance

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mitigation action. WCS was asked to determine, at a minimum, the presence or absence of resident and migratory species, especially Bicknell’s thrush, at a number of locations on the mountain, including the summit, the two summit parking lots, the Wilmington Turn, and the Lake Placid Turn on the memorial highway. During the summers of 2011, 2013, and 2014, WCS conducted point count surveys to detect migratory species at a total of 15 locations along a linear transect beginning at the summit of the mountain and following the roadway downward to an elevation outside of which helicopter landings occurred (3700 ft). Monitoring points were sampled using the same standard point count methods described above (Ralph et al. 1995) to specifically monitor the presence of Bicknell’s thrush and the four other aforementioned high elevation indicator species (blackpoll warbler, Swainson’s thrush, winter wren, and white-throated sparrow), in addition to any other migratory species present. Each monitoring point was sampled twice during the early June monitoring period, which extends from June 1 to June 20. The mitigation monitoring was conducted by different organizations in 2012 and 2015. WCS, however, sampled the same 15 points for a different project (described below) in 2015. Numerous authors have recently highlighted the perils of making inferences from uncorrected (raw) count data because few species are likely to be so evident that they will always be detected when present (MacKenzie et al. 2003, MacKenzie et al. 2006). These concerns, along with the increasing availability of tools for addressing them, led us to include an analysis of occupancy probability in our reporting on these and subsequent data collections on Whiteface. Occupancy is defined as species presence, or the proportion of area, patches, or sample units occupied by the species of interest (MacKenzie et al. 2006) and is used for many inferential purposes including questions about habitat selection, population dynamics, distribution, and range (MacKenzie et al. 2005). Between 2011 and 2015, 110 total detections of Bicknell’s thrush were recorded on the mountain. The species was detected at all but one of the sampling locations, although occurrence and calculated occupancy probability declined with elevation (Figure 3). A total of 14 other species have been detected to date in addition to the targets, and the numbers of additional species detected on the mountain has increased slightly over this five year period. These mitigation monitoring efforts did not detect any patterns to suggest a change in occupancy probability of Bicknell’s thrush in response to helicopter landings on the mountain. It is important to note, however, that training missions on the mountain occurred outside of the breeding season when there was no potential for direct effects on Bicknell’s thrush nest site selection or other behaviors. A study design to detect the impact of helicopters on Bicknell’s thrush or any other migratory or resident species would require a more robust and rigorous approach beyond the scope and resources of this mitigation monitoring study.

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Road Reconstruction The Olympic Regional Development Authority undertook reconstruction of the Whiteface Memorial Highway in 2014 and 2015. Concern existed for the potential for disturbances to Bicknell’s thrush from the elevated levels of human activity, noise, artificial lighting, and dust/pollutants that would occur during construction. The project entailed full roadbed reconstruction of two miles of the highway, with the rest resurfaced. The full reconstruction zones were anticipated to produce the greatest potential for disturbance to Bicknell’s thrush. The New York State Department of Environmental Conservation (NYSDEC) previously requested that WCS provide information on the degree to which Bicknell’s thrush habitat overlaps with these reconstruction zones such that any potential mitigation activities could be located in areas of highest potential benefit for the bird (Glennon 2014). The NYSDEC also recognized that, although the scope of potential mitigation opportunities may be limited, the understanding of Bicknell’s thrush use of Whiteface Mountain and the roadside habitat specifically, coupled with monitoring during the construction activity, would help determine how these activities may impact the bird. To that end, WCS was contracted by Rifenburg Construction, Inc. to monitor Bicknell’s thrush during the summer of 2014 and 2015 and to compare numbers of birds detected during these seasons with detections during previous years when no construction activity occurred on the mountain. WCS surveyed Bicknell’s thrush and other bird species at the 15 points previously used during the high-altitude helicopter training activities discussed above, as well as six additional points lower down the road in order to capture the full elevation range of potential Bicknell’s thrush habitat. As per all other work by WCS on the mountain, standard point count methods (Ralph et al. 1995) were used to assess presence/absence and relative abundance of Bicknell’s thrush and other high elevation species using counts 10 minutes in duration and divided into three time periods so that data could be compared with bird counts from other sources. At each sample point, birds were recorded by species, time period of detection (i.e., 0-3 minutes, 3-5 minutes, 5-10 minutes), activity (i.e., singing, calling, individual seen), and whether or not they were within 50 m of the observer. During these and other surveys, conditions believed to have the potential to influence detection probability for Bicknell’s thrush were recorded, including date, time of survey, ambient air temperature, wind and sky conditions, and any nearby sources of noise interference, such as running water. Bicknell’s thrush and 17 other species were detected during these surveys, including all of the additional montane target species (blackpoll warbler, Swainson’s thrush, winter wren, white-throated sparrow). During both 2014 and 2015, white-throated sparrow was detected most often on the mountain. Thirty-five and 23 detections of Bicknell’s thrush were recorded in 2014 and 2015, respectively, with the vast majority occurring at the first 15 sampling locations at the upper elevations on the mountain.

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Combined Information 2011–2015 Occupancy analysis (MacKenzie et al. 2006) was used to model the occurrence of Bicknell’s thrush and other montane species using the five years of data collected during these two monitoring efforts (Glennon 2015). Bicknell’s thrush was found to be positively influenced by elevation and, on average over 2011-2015, had a predicted occupancy probability of 0.87, indicating that 87% of sampling points were probably occupied by Bicknell’s thrush. Naïve occupancy (uncorrected for detection probability) averaged over 2011-2015, based on the number of points at which Bicknell’s thrush was detected out of the total of 15 points, was 0.71. Detection probability was variable over the five years of sampling and influenced by survey conditions, such as time of day (Bicknell’s thrush is active at early hours of the day in comparison to many bird species), wind conditions, and observer. The average probability of detection was 0.6, which is high given the conspicuousness of this species. Occupancy analysis for the other four target species yielded slightly higher rates of detection and occupancy than those of Bicknell’s thrush. These results indicate that all of these species are likely to occupy most sampling points on the mountain but that Bicknell’s thrush is a more difficult species to detect. Calculation of multiyear trends from modeled occupancy data demonstrated a slightly declining trend for Bicknell’s thrush and blackpoll warbler, while Swainson’s thrush, winter wren, and white-throated sparrow were stable (Figure 4). No Mountain Birdwatch occupancy trend data for 2011-2014 are available against which to compare this information because the Mountain Birdwatch program instituted a new protocol in 2010 and occupancy analyses of new data have not yet been made public. It is important to note that these are modeled occupancy trends and reflect only a five year time period from only a single location. As such, we caution against using them to draw conclusions about these species in other locations, and apparent trends should not be attributed to any specific causes. Results from both the uncorrected count data and the occupancy analysis provide a baseline which can continue to be used for comparison to future monitoring conducted on Whiteface Mountain. With these cautions in mind, we found no strong evidence to suggest that helicopter training or road reconstruction activities negatively affected usage of the study area by breeding Bicknell’s thrushes (Glennon 2015). However, it cannot be determined from these data whether or not helicopter training or road reconstruction activities adversely affected other Bicknell’s thrush behaviors or their nesting success.

BICKNELL’S THRUSH IN THE NORTHEAST Our work on Bicknell’s thrush in the Adirondacks has been focused intensely on one single location, primarily because Whiteface is so heavily used and is often subject to modifications in structure or use such that concerns arise over potential impacts to the species. Bicknell’s thrush has been studied much more extensively elsewhere in the Northeast and on its wintering grounds by VCE (see Strong et al. 2002, Strong et al. 2004, Lambert et al. 2005, McFarland et al. 2013).

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Vermont Field Studies Rimmer and McFarland (2013) describe their initial entry into the study of Bicknell’s thrush as having begun in 1992, when information about the species was practically non-existent and climate change was hardly on the radar, but concern over the impacts of acid rain, atmospheric pollution and recreation on mountaintops in the region warranted field studies to learn about the status and distribution of the species. An early coordination of volunteers from New York to Maine documented the occurrence of Bicknell’s thrush on 234 locations in the four-state region, 91% of which were above 900 m in elevation (Atwood et al. 1996). Bicknell’s thrush became recognized as an independent species in 1995 (Monroe et al. 1995) and this, combined with information from these early surveys, catalyzed a period of intense work on two Vermont mountaintops – Mount Mansfield (Stowe Mountain Resort) and Stratton Mountain. Similar but much more extensive than the WCS work on Whiteface, Rimmer et al. (2004) examined the use of these two ski areas by Bicknell’s thrush using a variety of field methods to investigate patterns in abundance, nesting ecology, home range sizes, and movements and other behaviors. Rimmer et al. (2004) found few significant differences for various population and reproductive parameters between areas developed for skiing and natural forests on each mountain. Nest predation rates did not differ between ski area and natural forest plots, nor did female brooding behavior, male feeding behavior, adult survivorship, nest success, breeding productivity, or movements of adults (Rimmer et al. 2004). Mansfield and Stratton have continued to serve as intensive study sites for VCE scientists and their work has resulted in a number of key findings, including the identification of the species’ uncommon and complex mating system (Goetz et al. 2003), the keystone importance of balsam fir in controlling Bicknell’s thrush demographics indirectly through the effect of cone mast on predator abundance (McFarland 2003), and the risks posed to Bicknell’s thrush and other high elevation spruce-fir species from climate change (Lambert et al. 2005). Work by VCE biologists on Stratton Mountain revealed unexpected levels of mercury accumulation in Bicknell’s thrush and other organisms (Rimmer et al. 2005). Mercury was found to increase with trophic position through the food web on Stratton, and these findings were included as part of a landmark partnership to compile mercury data from wildlife across the northeastern United States and Canada (Evers 2005). More recently, Bicknell’s thrushes were found to have even higher blood mercury levels during winter on their Caribbean wintering grounds (Townsend et al. 2013). These high levels of mercury that have been observed in Bicknell’s thrush have revealed that mercury is not only a potential threat to predatory species in aquatic environments, but also to wildlife species that occupy low trophic positions and live in terrestrial habitats, even in areas without point-source mercury pollution. Threshold effect levels of mercury in Bicknell’s thrush and songbirds in general have not been well-established (Seewagen 2010), however, and it remains to be determined what specific adverse effects, if any, mercury pollution is having on the species.

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Mountain Birdwatch In addition to these localized field studies, Bicknell’s thrush has been monitored throughout the Northeast since 2000 as part of the Mountain Birdwatch program of VCE. Mountain Birdwatch focuses primarily on Bicknell’s thrush, but also tracks other songbirds that breed in the montane fir and spruce forests of the Northeast. These data provide the only regionwide source of population information on these species. Mountain Birdwatch also tracks red squirrels and the conifer seeds that these avian nest predators consume. Mountain Birdwatch is a citizen science program fueled by the energies of more than 100 volunteers who count birds annually at 722 survey points within 130 mountaintop transects distributed in Maine, New Hampshire, Vermont, and northern New York. It was created in 2000 in order to monitor the abundance of montane birds in the region and to guide stewardship of high elevation forests by understanding the influence of landscape and habitat features on mountain bird distribution and abundance. In 2010, VCE launched a revised and updated Mountain Birdwatch 2.0, which improved upon the original program by (1) establishing a set of 130 routes randomly selected from within all U.S. potential Bicknell’s thrush habitat, (2) adopting modern count procedures that allow accurate estimates of avian density and occupancy, (3) establishing unified, measurable monitoring objectives linked to an international Bicknell’s thrush conservation action plan, and (4) developing a collaboration with Canada to systematically monitor Bicknell’s thrush across its entire breeding range. The change in protocol between the first and second versions of Mountain Birdwatch makes it challenging to conduct a direct analysis of long-term trends since the inception of the program. Separate analyses of different parts of these data reveal a mix of trends, with evidence of declines in core areas such as the White Mountains but no clear increase or decrease in others (Rimmer and McFarland 2013, Scarl 2011, Lambert et al. 2008). Canadian trends are more troubling, with steep declines in the maritime provinces of New Brunswick and Nova Scotia and lesser declines in Quebec (Rimmer and McFarland 2013).

CONCLUSIONS Bicknell’s thrush remains a subject of intense study and interest in the scientific and recreational birding community. As a species that thrives in some of the most inhospitable habitat in the region, it tests our reserves just to be willing to get out and study it. Its propensity for thick and impassable mountaintop forest, its tendency to make itself heard only at the very earliest and very latest hours of the day, and a mating system that makes regular assumptions about its numbers based on territorial behavior tenuous at best, provide a challenge to researchers and others who wish to document or even to catch a glimpse of this rare species. None of this has stopped a multitude of researchers and volunteer citizen scientists, however, and as a result, we now know much more about a bird that was only first described in 1882 (Ridgeway 1882) and was not recognized as a distinct species until 1995 (Monroe et al. 1995).

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Fitting with the scope of the Adirondack Journal of Environmental Studies, this paper has focused primarily on the breeding grounds of Bicknell’s thrush. What has been learned about the species on the breeding grounds has been in some cases surprising (e.g., no apparent change in occupancy in response to heavy levels of disturbance from ski area development, helicopters, and road construction), wildly puzzling (e.g., female defense polygynandry, a breeding system known in only one other North American songbird), and concerning in other cases (e.g., rapidly declining populations in some areas, elevated levels of mercury, and dependence on a habitat type that is being pushed off the globe by climate change). While Bicknell’s thrush may be able to thrive in ski areas in New York and Vermont, and although population trends in the Adirondacks appear positive (Scarl 2013), we cannot make conclusions about the fate of this migratory bird in our region without a consideration of the place in which it spends the majority of its life cycle – the Caribbean wintering grounds. The overwhelming majority of Bicknell’s thrushes winter on the island of Hispaniola. Unrelenting deforestation on Hispaniola, in Haiti in particular, highlights the fact that no future can exist for Bicknell’s thrush anywhere in its breeding range without significant efforts to conserve the Caribbean forests on which it depends for six months out of the year (Rimmer and McFarland 2013). Although most birds have been found to overwinter in government-protected lands in Haiti and the Dominican Republic, paper protection does not appear to translate to actual protection, and charcoal production, subsistence agriculture, logging, and squatting persist unchecked (Rimmer and McFarland 2013). Findings from both breeding season and wintering ground research have resulted in the creation of a large coalition of partners working to advance Bicknell’s thrush conservation. The International Bicknell’s Thrush Conservation Group (IBTCG), which has nearly 100 partners, aims to increase the global species population by 25% over the next 50 years, with no further net loss of distribution (IBTCG 2010). The mere existence of this group suggests that all is not lost, but much is required to achieve these ambitious goals. The northeastern U.S. holds a significant proportion of the global breeding range for Bicknell’s thrush. Of a species that may number fewer than 100,000 individuals worldwide, 24% of its potential U.S. habitat is in New York State (Lambert et al 2005). The potential role that New Yorkers can play in helping to safeguard the species is perhaps greater than in any other state. As the only endemic songbird in the Northeast, we have a responsibility for ensuring its future in our part of its range. Although climate change threatens the extent of its habitat in the Northeast, stable or increasing trends in Bicknell’s thrush population sizes in the Adirondacks and Catskills indicate that hope remains. There are several meaningful actions we can take. We suggest the following:

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1. Understanding, educating, and combating climate change. 2. Carefully managing the placement and design of ski areas, wind power facilities, and other forms of development on mountaintops occupied by Bicknell’s thrush and other high-elevation specialists. 3. Understanding and supporting efforts to reduce mercury pollution on both the breeding grounds and wintering grounds. 4. Supporting efforts to conserve broadleaf forests in the Caribbean. 5. Participating in citizen science efforts to monitor Bicknell’s thrush and other montane bird species. Figure 1. Montane bird abundance on Whiteface Mountain Study Sites 2004 – 2010

Figure 2. Pre- (2004 – 2007) and post- (2008 – 2010) construction abundance of montane birds in ski trail expansion area on Whiteface Mountain

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Figure 3. Average probability of occupancy by Bicknell’s thrush in relation to elevation at 15 monitoring points on Whiteface Mountain, 2011-2015. Bicknell’s thrush was detected at least once at all sampling points except 14.

Figure 4. Modeled 5-year occupancy rates for Bicknell’s thrush, blackpoll warbler, Swainson’s thrush, winter wren, and white-throated sparrow on 15 sample points on Whiteface Mountain, Wilmington, NY, 2011-2015

ACKNOWLEDGEMENTS

WCS acknowledges the field technicians who participated in data collection efforts on Whiteface from 2004 to 2014: Brian McAllister, Leslie Karasin, Steve Langdon, Sunita Halasz, Steve Halasz, Mark Dettling, Quentin Hays, Matt Maloney, Heidi Kretser, Scott van Laer, and Lewis Lolya. We also acknowledge the support of the Olympic Regional Development Authority, Overhills Foundation, U.S. Army, NYSDEC, and Rifenburg Construction, Inc., as well as the dedication of hundreds of citizen scientists who participate in the Mountain Birdwatch Program.

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L I TE R AT U R E C I T E D

Atwood, J. L., C. C. Rimmer, K. P. McFarland, S. H. Tsai, and L. R. Nagy. 1996. “Distribution of Bicknell’s Thrush in New England and New York,” Wilson Bulletin, 108: 650–661. Evers, David C. 2005. “Mercury Connections: The extent and effects of mercury pollution in northeastern North America,” BioDiversity Research Institute. Gorham, Maine. 28 pp. Glennon, M.J. 2014. Habitat Assessment for Bicknell’s Thrush on Whiteface Mountain as Related to Highway Reconstruction: Report for the New York State Department of Environmental Conservation, January 2014. Glennon, M.J. 2015. Occurrence of Bicknell’s thrush (Catharus bicknelli) along the Whiteface Memorial Highway II: Report to Rifenburg Construction, Inc., September 2015. Goetz, J.E., K. P. McFarland, and C.C. Rimmer. 2003. “Multiple Paternity and Multiple Male Feeders in Bicknell’s Thrush (Catharus bicknelli),” The Auk, 120: 1044–1053. International Bicknell’s Thrush Conservation Group. 2010. “A Conservation Action Plan for Bicknell’s Thrush (Catharus bicknelli).” J.A. Hart, C.C. Rimmer, R. Dettmers, R.M. Whittam, E.A. McKinnon, and K.P. McFarland, Eds. Unpublished report, International Bicknell’s Thrush Conservation Group. Available at http://www.bicknellsthrush.org/conservation.html. Lambert, J.D., K.P. McFarland, C.C. Rimmer, S.D. Faccio, and J.L. Atwood. 2005. “A practical model of Bicknell’s thrush distribution in the Northeastern United States,” Wilson Bulletin, 117(1):1-112. Lambert, J.D., D.I. King, J.P. Buonaccorsi, and L.S. Prout. 2008. “Decline of a New Hampshire Bicknell’s Thrush Population, 1993–2003,” Northeastern Naturalist, 15: 607–618. MacKenzie, D. I., J. D. Nichols, J. E. Hines, M. G. Knutson, and A. B. Franklin. 2003. “Estimating site occupancy, colonization, and local extinction when a species is detected imperfectly,” Ecology, 84:2200–2207. MacKenzie, D. I., J. D. Nichols, N. Sutton, K. Kawanishi, and L. L. Bailey. 2005. “Improving inferences in population studies of rare species that are detected imperfectly,” Ecology, 86:1101–1113. MacKenzie, D. I., J. D. Nichols, J. A. Royle, K. H. Pollock, L. L. Bailey, and J. E. Hines. 2006. Occupancy Estimation and Modeling: Inferring Patterns and Dynamics of Species Occurrence. Burlington, Massachusetts: Elsevier.

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McFarland, K.P. 2003. “A Good Year for Fir Cones,” Northern Woodlands Magazine— The Outside Story. McFarland, K.P., C.C. Rimmer, J.E. Goetz, Y. Aubry, J.M. Wunderle Jr., A. Sutton, J.M. Townsend, A. Llanes Sosa, and A. Kirkconnell. 2013. “A winter distribution model for Bicknell’s thrush (Catharus bicknelli), a conservation tool for a threatened migratory songbird,” PLOS ONE, 8(1): e53986. Monroe, B.L., R.C. Banks, J.W. Fitzpatrick, T.R. Howell, N.K. Johnson, H. Ouellet, J.V. Remsen, and R.W. Storer. 1995. “Fortieth supplement to the American Ornithologists’ Union check-list of North American birds,” The Auk, 112: 819-830. Ralph, C.J., S. Droege, and J.R. Sauer. 1995. “Managing and monitoring birds using point counts: standards and applications,” USDA Forest Service General Technical Report PSW-GTR-149. Ridgeway, R. 1882. “Descriptions of two new thrushes from the United States,” Proceedings of the U.S. National Museum, 4:377-378. Rimmer, C.C. 2008. “Bicknell’s thrush (Catharus bicknelli),” in The Second Atlas of Breeding Birds in New York State (K.J. McGowan and K. Corwin, Eds.). Itaca, NY: Cornell University Press. Rimmer, C. C., K.P. McFarland, J. Townsend, W.G. Ellison, and J.E. Goetz. 2015. “Bicknell’s Thrush (Catharus bicknelli),” in The Birds of North America Online (A. Poole, ed.). Ithaca, NY: Cornell Lab of Ornithology. Rimmer, C.C., and K.P. McFarland. 2013. “Bicknell’s thrush: a twenty-year retrospective on the northeast’s most vulnerable songbird,” Bird Observer, 41(1):9–16. Rimmer, C.C., J.L. Atwood, K.P. McFarland, and L.R. Nagy. 1996. “Population density, vocal behavior, and recommended survey methods for Bicknell’s Thrush,” Wilson Bulletin, 108:639-649. Rimmer, C.G., K.P. McFarland, J.D. Lambert, and R.B. Renfrew. 2004. “Evaluating the use of Vermont ski areas by Bicknell’s thrush – applications for Whiteface Mountain, N.Y,” Final report to the Olympic Regional Development Authority, December 2004. Seewagen, C.L. 2010. “Threats of environmental mercury to birds: knowledge gaps and priorities for future research,” Bird Conservation International, 20:112-123. Scarl, J.C. 2011. Annual report to the United States Fish and Wildlife Service. Vermont Center for Ecostudies. 17 pp.

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Scarl, J.C. 2013. Mountain Birdwatch 2013: Annual report to the United States Fish and Wildlife Service. Unpublished report. Vermont Center for Ecostudies, Norwich, VT. 24 pp. Strong, A.M., C.C. Rimmer, K.P. McFarland and K. Hagan. 2002. “Effects of mountain resorts on wildlife,” Vermont Law Review, 26(3): 689-716. Strong, A.M., C.C. Rimmer, and K.P. McFarland. 2004. “Effect of prey biomass on reproductive success and mating strategy of Bicknell’s Thrush (Catharus bicknelli), a polygynandrous songbird,” The Auk, 121:446-451. Townsend, J.M., C.C. Rimmer, C.T. Driscoll, K.P. McFarland, and E.E. IñigoElias. 2013. “Mercury concentrations in tropical resident and migrant songbirds on Hispaniola,” Ecotoxicology, 22:86-93. Zar, J.H. 1999. Biostatistical Analysis: Fourth Edition. Pearson Education, 123 pp.

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