San Diego Zoo Wildlife Alliance Journal July 2023

Bolstering a Brighter Future for Amazonia

JULY/AUGUST 2023

Journey Through Our Conservation Work This issue of the San Diego Zoo Wildlife Alliance Journal focuses on the Amazonio hub. To learn more about our collaborative conservation programs around the world, including our wildlife care at the San Diego Zoo and San Diego Zoo Safari Park, visit sdzwa.org.

Contents

2 President/CEO’s Letter

3 By the Numbers

4 Findings

6 Meet Our Team

8 Hot Topics

26 Events

28 Wildlife Explorers Page

29 Last Look

Cover Story

10

Cub Scouting

Alba the Andean bear’s new cubs aren’t just adorable. The precious pair is helping wildlife care specialists at our Zoo study how this secretive South American species raises its young in managed care, as well as in its native range in the Andes.

Features

16

Troubled Waters

Gold is universally desired for its monetary value, but the mining process is costly for the environment, with wildlife in the Peruvian Amazon often paying the price.

20

Powerful Predators of the Amazon

Native to South and Central America, black caimans are amphibious carnivores that may appear impervious to threats. But there are challenges lurking in the watery world of this species—and its reptilian relatives.

24

Visualize It

For some species in the Amazon, imitation isn’t the highest form of flattery— it’s the best bet for survival.

On the Cover: Andean bear cubs Tremarctos ornatus. Photo by: Ken Bohn, SDZWA photographer

Pacific Islands ‘Alalā Oceans Polar Bear & Penguin Asian Rainforest Tiger Savanna Elephant & Rhino Australian Forest Platypus & Koala

African Forest Gorilla Southwest Desert Tortoise & Burrowing Owl

Amazonia Jaguar

PHOTOS

BY: KEN BOHN/SDZWA

JOURNAL

SENIOR EDITOR Peggy Scott

STAFF WRITERS

Donna Parham

Elyan Shor, Ph.D.

Ebone Monet

Alyssa Leicht

COPY EDITOR Eston Ellis

DESIGNER Christine Yetman

PHOTOGRAPHERS

Ken Bohn

Tammy Spratt

DESIGN AND PRODUCTION

Kim Turner

Lisa Bissi

Jennifer MacEwen

PREPRESS AND PRINTING Quad Graphics

Let's Stay Connected

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The Zoological Society of San Diego was founded in Octo ber 1916 by Harry M. Wegeforth, M.D., as a private, nonprofit corporation, which does business as San Diego Zoo Wildlife Alliance.

The printed San Diego Zoo Wildlife Alliance Journal (ISSN 2767-7680) (Vol. 3, No. 4) is published bimonthly, in January, March, May, July, September, and November. Publisher is San Diego Zoo Wildlife Alliance, located at 2920 Zoo Drive, San Diego, CA 92101-1646. Periodicals postage paid at San Diego, California, USA, and at additional mailing offices. POSTMASTER: Send address changes to San Diego Zoo Wildlife Alliance, P.O. Box 120271, San Diego, CA 92112-0271.

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Allies for Wildlife and Conservation in Amazonia

Our Amazonia Conservation Hub is home to some of our most inspiring and innovative initiatives, creating new possibilities for the world’s wildlife and the ecosystems that sustain us on this planet. Our ability to support our partners and find solutions to contemporary conservation challenges starts here—at the San Diego Zoo and San Diego Zoo Safari Park—with the support of millions of allies like you! In this issue of the San Diego Zoo Wildlife Alliance Journal , we explore the steps we take to support the next generation of wildlife allies, what we’re learning about the challenges facing wildlife in Amazonia, and the aweinspiring hope that comes with supporting conservation initiatives that protect wildlife. Conservation starts with people, and we are working to support the next generation of veterinary students by decreasing the barriers to participation. Our teams are collaborating with communities here locally, and those throughout the veterinary profession, to ensure that anyone with a passion for wildlife and dedication to conservation education gets an equal opportunity to develop their career at the San Diego Zoo and San Diego Zoo Safari Park. When we support the next generation of wildlife allies, we create hope for conservation and species in need of our help around the world. There is still so much to be learned about wildlife in Amazonia, the challenges they face, and the conditions they need to thrive. Our teams of conservation scientists are working with our local partners at the Wildlife Conservation Laboratory in the Los Amigos Conservation Concession to explore the health of regional ecosystems and the impact on the wildlife that depends on them. We are proud of all our team members involved with the transformative work in Amazonia, and we are elated by seeing their accomplishments recognized when San Diego Zoo Wildlife Alliance was recently named an Honoree in Fast Company’s 2023 World Changing Ideas Awards, in the Nature category. Through the In Situ Laboratory initiative, alongside our conservation partners, we’re helping decentralize scientific discovery by creating functional laboratories and workspaces—right where they are needed.

We hope you take the time this summer to join us at the San Diego Zoo and the San Diego Zoo Safari Park to connect with the world’s wildlife. Your visit helps change the world—and together as allies for wildlife, we can create a world where all life thrives.

As part of San Diego Zoo Wildlife Alliance’s commitment to conservation, this magazine is printed on recycled paper that is at least 10% post-consumer waste, chlorine free, and is Forest Stewardship Council ® (FSC ®) certified. FSC ® is not responsible for any calculations on saving resources by choosing this paper.

Paul A. Baribault President and Chief Executive Officer

BY THE NUMBERS

Plenty to Discover

Covering about 40 percent of South America across 9 countries, Amazonia contains the single largest rainforest in the world. Its lush forests and waters host more species of wildlife than any other terrestrial ecosystem on Earth, and scientists document new species nearly every other day. With almost one-fifth of the forest lost already, it’s now more vital than ever that we protect what some call “the lungs of the planet.”

2023 Board of Trustees

OFFICERS

Javade Chaudhri, Chair

Steven G. Tappan, Vice Chair

Gary E. Knell, Vice Chair

Steven S. Simpson, Treasurer

20% The Amazon River contains 20 percent of the world’s flowing fresh water.

100+

With more than 100 new species documented each year, Amazonia still has much to teach us.

123,000,000,000

Scientists estimate that the Amazon contains about 123 billion tons of carbon. As a carbon sink, it plays a crucial role in providing environmental stability.

1,863 One square mile of forest in Rondonia, Brazil,

Richard B. Gulley, Secretary

TRUSTEES

Rolf Benirschke

Kathleen Cain Carrithers

E. Jane Finley

Clifford W. Hague

Linda J. Lowenstine, DVM, Ph.D.

Bryan B. Min

TRUSTEES EMERITI

Berit N. Durler

Thompson Fetter

George L. Gildred

Robert B. Horsman

John M. Thornton

Executive Team

Paul A. Baribault

President and Chief Executive Officer

Shawn Dixon

Chief Operating Officer

David Franco

Chief Financial Officer

Erika Kohler

Executive Director, San Diego Zoo

Lisa Peterson

Executive Director, San Diego Zoo Safari Park

Nadine Lamberski, DVM, DACZM, DECZM (ZHM)

Chief Conservation and Wildlife Health Officer

Wendy Bulger

General Counsel

David Gillig

Chief Philanthropy Officer

Aida Rosa

Chief Human Resources Officer

Chief Marketing Officer 400+

Indigenous tribes rely on Amazonian forests for protection and survival.

David Miller

San Diego Zoo Wildlife Alliance (SDZWA) protects and restores nature in eight

Frozen Cells Provide Fresh Insights

In 2004, SDZWA established a cell line from the last living po‘ouli Melamprosops phaeosoma, a species of extinct Hawaiian honeycreeper. These cells were the first viable material from an extinct species to be cryopreserved (frozen), and they remained dormant in our Wildlife Biodiversity Bank’s Frozen Zoo® until recently, when our team thawed one precious vial for genome sequencing. Sequencing the po‘ouli genome provides evolutionary and genetic information that could benefit conservation of many extant—but critically endangered—Hawaiian songbirds. Our team also used fluorescent imaging for detailed visual examinations of the cells, providing insight into preservation of cells that can be applied to dozens of additional species. Once cryopreserved, these cell lines will lend hope for future genetic rescue efforts.

Demand Reduction Campaign Launched

After two years of pandemic-related delays, SDZWA and partners launched a bear bile demand reduction campaign in three rural provinces in Cambodia, in collaboration with the Cambodian Ministry of Health. The campaign lasts six months and is intended to encourage greater adoption of scientific medicine, particularly when treating ailments that are currently treated with bear bile, such as bruising and postpartum illness. This will result in better health for local communities and reduced hunting of local bear populations. To suggest alternatives to bear bile through marketing, the team is putting up posters and handing out flyers and basic first aid kits with campaign messages printed on them.

A Better Way to Grow Oaks

Micropropagation involves cultivating plants under controlled conditions in the lab, allowing us to grow endangered plants away from the threats they face. Some plants can be easily micropropagated, but most—including the coastal sage scrub oak Quercus dumosa, an endangered oak found only in California and Baja California, Mexico—cannot. Our Plant Conservation team analyzed wild-grown leaves to identify the nutrients these oaks need to survive. Then, in the lab, our team added a blend of antioxidants to the tissue culture we developed, boosting the health of oak shoot tips growing in the medium. Typically, every plant species requires its own tailored medium; however, our “omni medium” has proven effective for several oak species and other endangered Southwest region flora.

Den Monitoring Developments

One of the priorities of our polar bear Ursus maritimus maternal den studies in Svalbard, Norway, is to advance technologies that enable autonomous monitoring of bear families emerging from their dens. Over the last few years, our “Mini DenCam” video cameras—co-developed by SDZWA’s Conservation Technology Lab and partners at Polar Bears International—have been a reliable platform for data collection. This year, our partners also tested a drone with an ultra-wideband radar sensor that can identify dens under the snow. This novel technology has tremendous promise for locating dens, and it may be adapted to other areas of the Arctic where protective measures are necessary to prevent den disturbance caused by industrial or recreational activities.

conservation hubs on six continents. Below are recent discoveries and progress reports from around the world.

Join Us in Saving Wildlife

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What is the coolest thing about your job?

I enjoy discovering new species, but most of all, I am happy we are collecting new data in the Peruvian Amazon—a vast jungle region in northeastern Peru. Few studies are dedicated to this part of the Amazon rainforest, so not much is known about its wildlife ecology. That is what makes the conservation work we are doing with our local partners so important. For example, our team is gathering data to estimate the populations of endangered species such as mountain tapirs and jaguars, to aid in their conservation. We analyze trail camera images, and to our delight, we document new wildlife discoveries all the time.

What book or film influenced you or made a strong impression?

The book that made the strongest impression on me would be Collapse: How Societies Choose to Fail or Succeed by Jared Diamond, a popular science author and geographer. As for movies, I would have to say The Mission, which describes how Spanish Jesuits tried to protect a remote South American Indigenous tribe during the 18th century.

What has surprised you about working with SDZWA?

The passion people have for protecting wildlife, including those who are working at the San Diego Zoo and San Diego Zoo Safari Park, as well as the researchers we collaborate with from all over the globe.

What do you see as the future of wildlife conservation?

There is a lot of work yet to be done. I am hopeful that we are making a meaningful difference. The greatest challenges to conservation are often found in the countries that are the richest in biodiversity, where there is

José Luis Mena Álvarez, Ph.D.

As scientific coordinator for SDZWA’s Amazonia conservation hub, José Luis Mena Álvarez specializes in ecology and conservation with an emphasis on wildlife. He collaborates with partners across the globe to plan, coordinate, and direct wildlife conservation projects in the Peruvian Amazon.

also a great need for development. It is important that we educate people about human-wildlife coexistence by promoting livelihoods that favor both people and wildlife.

QWhat was a turning point or defining moment in a project or program you’ve worked on?

When we decided to work on developing solutions to the urgent issue of human-wildlife coexistence. We are working with local conservation partners to improve human-wildlife coexistence. This topic needs immediate attention to improve our conservation impact, for both jaguar populations and the Amazon forest where this species and its prey exist. Human-wildlife conflicts are an emergent threat to this species, and it appears to be connected with illegal trafficking of jaguar parts.

QWhat is your favorite animal?

Why?

Bats—they are one of the most diverse groups of vertebrates, and many of them are threatened. They play critical roles in ecosystems, including seed dispersal and forest regeneration, pollination, and the suppression of insect pests in agriculture. Marsupials are also very interesting to me. In fact, during the Paleogene and Neogene Periods, 66 million to 2.6 million years ago, South America was the continent with the largest marsupial diversity in the world. Currently, there are only about 50 marsupial species left in the Peruvian Amazon.

QWho or what has inspired you?

Nature itself. I enjoy taking pictures of wildlife and sharing information through social media, to promote involvement in wildlife conservation and to increase appreciation for wildlife, life, and nature.

A New School of Thought:

Supporting an Inclusive Approach to Veterinary Education

The road to becoming a veterinarian is long, and some students face more barriers than others. SDZWA Senior Veterinarian Matthew E. Kinney, DVM, DACZM, maps the route for a smoother course to success.

San Diego Zoo Wildlife Alliance has a long and proud history of providing mentorship to visiting veterinarians and veterinary students. Additionally, the San Diego Zoo and San Diego Zoo Safari Park veterinary departments mentor residents in zoological medicine through a world-renowned collaboration with one of the top veterinary schools in the country, the University of California, Davis School of Veterinary Medicine. This intensive, three-year program prepares residents to become the next generation of leaders in zoological medi-

cine and surgery. As such, our veterinary training programs are highly sought after and have a finite number of positions. Thus, selection of candidates for the programs is highly competitive.

Veterinary medicine has been identified as one of the least diverse professions in the US, and the American College of Zoological Medicine has recently formed an ad hoc committee to evaluate diversity in zoological medicine and identify opportunities for improvement. An essential component of diversity, equity, and inclusion (DEI) initiatives is identification of barriers that may exclude individuals from a project or program. We

recently recognized that while our training programs are some of the most respected and sought after, there are barriers to entry into these programs for many. A candidate’s inability to fund travel and lodging for six to eight weeks has the potential to exclude them from our programs.

In an effort to make our veterinary training programs accessible to all interested students—not only those with the financial means to travel and lodge in San Diego—we have been working closely with our Philanthropy department and with Quincey Penn, SDZWA’s director of diversity, equity, and inclusion, to secure funds to support

Sharing knowledge: Author Matt Kinney (above) advises veterinary students during a medical procedure.

individuals interested in training at the Zoo and Safari Park. In early 2023, we hosted our inaugural veterinary externs as part of this revised program, and have secured funding from the Institute of Museum and Library Services to host an additional 34 students over the next 3 years. We’ve expanded the support provided to students, and we sponsor their attendance at a national zoological medicine conference, where they can present research and network to further advance their careers.

Our intent is to continue to identify funding sources to support veterinary training and DEI programs, and establish our orga-

nization as a model other institutions can look to, in order to reduce barriers to entry and advance DEI in zoological medicine.

There are many benefits to advancing programs that promote diversity, equity, and inclusion in zoological medicine at SDZWA. The most obvious is that it is the right thing to do. Financial challenges that preclude a student from taking part in a training program—despite their qualifications, interests, and potential contributions to zoological medicine—have the effect of creating an exclusive program, and pose a significant barrier to entry. Our current program has shifted the paradigm to be

inclusive to all interested trainees, and not only to those who can afford this experience.

Our global conservation impact continues to expand, and by supporting inclusive training programs, we have the potential to recruit diverse individuals with the expertise to make a difference. The zoological medicine and conservation challenges that we seek to solve are enormous. To provide solutions, we need to build alliances and collaborate with individuals who bring diverse and novel perspectives to the challenges we face—now and in the future.

Cub Scouting

Alba Welcomes a Precious Pair

BY KAT REED, DVM, MSC, MANZCVS, AND LINDSEY SHAFER | PHOTOS BY KEN BOHN

On December 10, 2022, two tiny Andean bear cubs—a male and a female—were born to 8-year-old sow (mom) Alba, and 12-year-old boar (dad) Turbo, at the San Diego Zoo. Since then, both cubs have grown by leaps and bounds, and they continue to hit important milestones.

The cubs were named in the Indigenous Quechua language, which is spoken in the South American countries of Colombia, Ecuador, Peru, Bolivia, and Argentina, where Andean bears live. The male cub is named Ransisku (pronounced ron-SIS-koo), the Quechuan form of “Francis,” and the female is Suyana (soo-YA-na), Quechuan for “hope.” Their names were chosen by Cathy Stiefel and Keith Behner, namesake donors for the Stiefel-Behner Research Program at Cocha Cashu Biological Station in San Diego Zoo Wildlife Alliance’s Amazonia Conservation Hub.

DID YOU KNOW?

Andean bears have only 13 pairs of ribs, one pair less than other bears.

Not only is this an exciting time for wildlife care specialists and San Diego Zoo Wildlife Alliance, but it marks a significant addition for a vulnerable species. The only bear species in South America, Andean bears Tremarctos ornatus can be found along the Andes mountain range. They are also called spectacled bears, for the light-colored fur that typically appears as rings around their eyes, resembling glasses or “spectacles.” They are a true arboreal species, and build elaborate nests and platforms in trees to feed from and sleep in. There are only about 2,000 Andean bears left in their native habitats, which is why our two new additions are so significant.

Quite a Bear Pair

The journey of our Andean bear cubs began all the way back in spring of 2022. Andean bears are solitary, only coming together to breed or if a mother is raising cubs. Beginning in April, our wildlife care team began noticing subtle behavioral changes in both Turbo and Alba, indicating to us they were ready to interact. These changes included vocalizations, as Andean bears make a “cooing” noise, which can be a friendly greeting toward one another. Another indication that the bears were ready? They started building their nests near the door that connects the two habitats.

While this pair has been introduced successfully multiple times before, the speed at which the introduction progresses is up to Alba. Before the bears shared a physical space, we began by offering them the opportunity to interact nose to nose, with a door in between. We closely observed these interactions, and once Alba showed positive signs toward Turbo, we knew they were ready to take their relationship to the next level.

The bears moved into a shared habitat on May 10, and bred not long after. This is when the waiting game began, because while we knew exactly when Turbo and Alba bred, this species experiences delayed implantation—meaning that once the egg is fertilized, there is a prolonged and highly variable period between fertilization and the beginning of embryonic development. This is an adaptation to ensure the pregnancy will only progress when resources are abundant enough to support the growing cubs.

Establishing a Timeline

Based on the breeding we observed last spring, we assumed that implantation would occur sometime in the fall. To prepare, team members began reacquainting Alba with regular ultrasound examinations. For a previous pregnancy, Alba learned to sit and stay focused on a target smeared with avocado and peanut butter, while veterinarians offered an ultrasound. Starting in August, we once again began offering ultrasounds weekly. In mid-November, we saw the first evidence of pregnancy on ultrasound. First, we observed a single fetal heartbeat, but the next week, we confirmed two fetal heartbeats.

As the twins developed, veterinarians could monitor development of the cubs’ skeletons, hearts, and abdominal organs. Each week, they measured the developing fetuses. The team entered this information in the international Species Survival Plan database for Andean bear pregnancies, helping to create a database of growth milestones for Andean bear breeding programs around the world. The veterinary team had fetal measurements from Alba’s previous pregnancy, but—just as with human pregnancies— twins may be slightly smaller than a single offspring. Because she gave birth to a single cub last time, the twins’ due date relied on a best estimate.

A couple of days before the cubs were born, Alba’s natural maternal instincts started to show. She began bringing a large amount of hay into her den, and her body began changing, which indicated to our team that birth was likely right around the corner. Sure enough, just a few days later, we heard—via a baby monitor—telltale joyful noises from the newborns. To give Alba as much privacy as possible, we observed her only via a camera

in her den. Based on review of the footage, the first cub was born around 1:30 a.m., and the second was born sometime between 4:30 and 5 a.m. This is the second time Alba has given birth, and watching her natural maternal instincts with the cubs is always a beautiful and amazing experience.

Privacy, Please

Andean bear mothers are incredibly secretive, and Alba is no exception. She kept the cubs close, and they didn’t start to venture out of the den on their own until they were nearly three months old. But even when care specialists couldn’t directly observe developments, they were able to document the cubs’ critical milestones. Our team observed the cubs holding their heads up at around 37 days old, and their eyes opened at around 40 days old.

Our optimism continued to grow when the cubs began coming out of the den on their own, at around 75 days old. All these developmental milestones help us to better understand Andean bears in their native range. Studying Alba’s behavior in her den offers insight into nesting habits and preferences.

The excitement of the new Andean bear cubs is just beginning, as cubs usually stay with their mother until they are around a year and a half old. We hope you’ll visit these incredible Andean bears for yourself, and enjoy all the fun antics that are happening daily in the Zoo’s Andean bear habitat!

Kat Reed, DVM, MSc, MANZCVS (Medicine of Zoo Animals), is a veterinary clinical fellow with San Diego Zoo Veterinary Services. Lindsey Shafer is a senior wildlife care specialist at the San Diego Zoo.

Family album: (opposite page) Turbo, the cubs’ sire, rests in his climbing structure; This page, clockwise from top center: Alba snuggles with daughter Suyana; male cub Ransisku stops for a moment; Ransisku is on the move again; Alba keeps an eye on her offspring.

TROUBLED WATERS

Environmental Effects of Gold Mining

BY CAROLINE MOORE, DVM, PH.D.

PHOTO BY: SDZWA

Gold has fascinated people for centuries, and is considered one of the most valuable materials on Earth. Yet, methods to collect it often have destructive consequences for people, wildlife, and ecosystems.

The global price of gold remained unchanged in 2022 from a record high in 2021, demonstrating continuing worldwide demand. To give a perspective of the gold economy close to home, domestic gold mining production in the US was estimated at nearly $10 billion in 2022, yet the gold resources in the US are considered to be only a small percentage of total global gold resources.

A Global Industry—and Concern

Peru was one of the world’s top 10 gold producers in 2022. (The top 10 gold producers in 2022 were China, Australia, Russia, Canada, the US, Mexico, Kazakhstan, South Africa, Peru, and Uzbekistan.) In the Peruvian Amazon, San Diego Zoo Wildlife Alliance (SDZWA) partners closely with local communities and nongovernmental organizations (NGOs) to better understand, mitigate, and prevent gold mining’s threats to wildlife.

A decade ago, gold prices spiked after the great recession, and a new wave of people came into the Madre de Dios region of the southeast Peruvian Amazon with the intent to mine gold. With a few rudimentary devices and access to the rivers, anyone willing to perform hard labor can mine up to several hundred dollars’ worth of gold a day—a life-changing amount of money, for many families. As gold demand remains steady, it has created an important and continued source of income for many in the Peruvian Amazon. But this is not without environmental and social impacts.

PHOTO BY: (ABOVE) KEN BOHN/SDZWA

DID YOU KNOW?

In 2022, 3,612 tons of gold were produced in the world.

Gold mining requires large swaths of accessible land, and the often illegal and remote nature of mining can push local and indigenous communities away, through criminal activities, human rights abuses, and contaminated food and water sources from the extensive use of mercury throughout the process.

Considering Effects

Gold in the Peruvian Amazon is not found in large nuggets, like those of the California Gold Rush. Those gold nuggets were large enough for John Sutter to pick up and show off the gold flecks in 1848, triggering crowds of miners rushing to California’s mountain rivers over the next 10 years. In contrast, the gold in the Amazon is so tiny and fine it is called gold dust, and is seemingly laid down everywhere the rivers touch. The Madre de Dios River in the Amazon is not static—it moves and travels with time, creating oxbow lakes, where the river bends away but leaves a curve of water behind (a favorite haven for giant river otters and yellow-spotted river turtles). Every new path carved and

old path left behind leaves a trail of gold. Deforestation—via clear cutting and wildfires—is one result when miners seek access to the gold-containing silt. Since the gold is too small to pan and sift, toxic mercury is mixed with silt in giant barrels, often stirred by hands and feet, to separate the gold dust from the silt. Mercury and gold bind together, and miners collect and burn this amalgam, vaporizing the mercury and leaving behind pure gold.

Mercury in its many forms is toxic to people, animals, and plants—aquatic and terrestrial. It is a natural component of our ecosystems, but it is usually not present in high concentrations at the earth’s surface. However, mercury-based gold mining techniques leave mercury behind, exposing people and animals to toxic levels, through water and food sources. Mercury can bioaccumulate in an individual over time, and biomagnify up food chains, so that top predators carry higher and higher amounts of mercury. High levels of exposure compromise brain function and ability to reproduce, as well as harming other organs. This

can result in blindness, abnormal behavior, paralysis, and even death. People in the Peruvian Amazon have been documented carrying mercury levels above what the World Health Organization calculates as “safe,” which has compromised their health.

SDZWA team members supported a recent study demonstrating that when intact old-growth forests are located next to mercury-based gold mining operations, they can act like a sponge to capture vaporized mercury, allowing it to integrate into the ecosystem at levels comparable to industrial mercury pollution. This is big news, as terrestrial wildlife species—including birds, bats, and carnivores—were historically thought to be at a lower risk for mercury exposure, compared to aquatic species such as giant river otters and fish. Yet, we are finding that almost all tested terrestrial animals in forests next to gold mining operations have detectable mercury levels in their hair or feathers. We do not yet know what this means for the protection and biodiversity of the Amazon. But we are working hard to find out more, and to fully understand the

Deep cuts: A gold mining operation clears a swath of much-needed rainforest across the river from the Los Amigos Conservation Concession, leaving behind mounds of sand and rocks.

PHOTO BY: SDZWA

mercury threat to Amazonia ecosystems, where the mercury is coming from (whether mining or other sources), and how exposure changes the health of wildlife, communities, and forests within the Amazon.

Damage Control

Easily observed from satellite imagery, the scale of destruction by gold mining is massive. As the Peruvian government works to reduce illegal gold mining in one region, it pops up in other regions. Gold mining expansion up the Madre de Dios River, within the buffer region to the Manu National Park, has been devastatingly evident on each trip we make to the Wildlife Conservation Laboratory at the Los Amigos Conservation Concession. As we travel up the river, the boat has to stick to deeper channels, and cruise around mining equipment and operations that spill across the river as the dry season exposes more silt. When we sit on the bluffs of the Estación Biológica Río Los Amigos to watch the sun set behind the Andes, we see a gaping, growing hole where a forest once stood across the Madre de Dios River, smell the forest fires, and hear the chain saws and ever-present fuel and water pumps. Behind us sits the protected 360,000-acre Los Amigos Conservation Concession, an oldgrowth forest that was once the site of hunting and logging operations. Today, it is home to one of the most valuable biodiversity hotspots within the Amazon region. This forest is home to at least 12 globally threatened species, 11 primate species (some found only at this site), over 550 bird species, and over 4,300 species total. Additionally, charismatic Amazonian fauna—

including giant otters, emperor tamarins, harpy eagles, red howler monkeys, spider monkeys, whitelipped peccaries, and jaguars—all call this region home.

Saving Tomorrow, Today

With our partners, we collect over 800 feather and hair samples annually from terrestrial and aquatic wildlife in the Madre de Dios region. We can then test these samples for the presence of mercury. By establishing a gold-standard mercury testing pipeline at the Wildlife Conservation Laboratory, we are ensuring that annual mercury measurements throughout the food chain, and soon in the environment, can be monitored by local scientists, in conjunction with mercury monitoring projects by other NGOs and laboratories throughout Peru. Together, we hope to build one of the strongest networks of mercury data in a region impacted by mining, so that we can provide evidence to support the need for urgent changes. Mercury-free methods of gold mining can be implemented, and mining with restoration plans in place can be established. Further, changes in human behavior can reduce the demand for gold. Supporting these changes will require multidisciplinary teams—from wildlife veterinarians, to social scientists and local communities—to take on the issue of unsustainable gold mining and propose alternatives to ensure that people, wildlife, and ecosystems can thrive.

At home in the Amazon:

Top: Jaguars are strong swimmers and are adapted to using habitats along the many rivers in the Amazon rainforest. Center: The harpy eagle is the largest and most powerful raptor in South America. As a top predator, it is vulnerable to mercury poisoning. Bottom: The Peruvian spider monkey prefers well-protected, old-growth forests and quickly disappears from areas with human encroachment.

Caroline Moore, DVM, Ph.D., is a scientist for SDZWA.

Diving into the Watery World of Caimans

BY DONNA PARHAM

POWERFUL PREDATORS AMAZONIA I

t’s nighttime at the Stiefel-Behner Research Program at Cocha Cashu Biological Station in Peru’s Manu National Park. San Diego Zoo Wildlife Alliance (SDZWA) scientist Adi Barocas, Ph.D., is slowly patrolling the shore of the oxbow lake in a (surprisingly small) inflatable boat. He’s in search of the Amazon’s largest predator: the black caiman Melanosuchus niger. “We travel along the banks with spotlights and scan the bank vegetation,” says Adi. “The red reflection of light in their eyes makes caimans visible to us in the darkness. Sometimes they dive or swim away with sudden movements, and there is a splash,” which Adi admits “can be a little bit scary.” But, he says, “It’s

OF

exciting to find caimans—the larger ones especially impress me.” Black caimans were among the first reptiles studied at Cocha Cashu, and are part of the reason the biological station was founded there in 1969.

Cocha Cashu’s Caimans

Widely distributed throughout the Amazon Basin, black caimans can be more than 16 feet long—they’re the largest of the New World crocodilians. They hunt in the water and on land, emerging mostly at night. Large adults prey on fish and turtles, as well as capybaras and other mammals. Juveniles prey on small fish, frogs, and invertebrates. During the wet season, as the

area floods, they have plenty of options for the kind of quiet waters they prefer. But in the dry season, they congregate in lakes and rivers. That makes Cocha Cashu prime habitat.

“Oxbow lakes are unique ecosystems, formed when rivers change their course,” says Adi. “Because the water in them is not commonly flowing, they are relatively productive ecosystems that have unique animal and plant communities. Oxbow lakes like Cocha Cashu have a high abundance of medium and large fish, which sustains stable populations of giant otters and black caimans.”

Once they spot a caiman, Adi estimates its size and records its location.

“Black caimans are more active at night, which is why we study them during these hours,” says Adi. “Working in the oxbow lakes at night is more pleasant, because it’s not as hot as during daytime.” Adi’s team has been doing nighttime spotlight surveys in 22 oxbow lakes since 2019. “The idea is to estimate their abundance, and to find out what the best type of habitat for them is,” says Adi. “Our experience, so far, suggests that the abundance of large individuals is higher in protected area oxbow lakes without fishers and miners. We are also interested in black caiman interactions with giant otters, because these two species are the top carnivores in Amazon freshwater ecosystems.”

Caring for Caimans

Kim Gray, SDZWA curator of herpetology and ichthyology, is a member of the International Union for Conservation of Nature (IUCN) Crocodile Specialist Group, a network of experts working together to provide scientific advice to conservation organizations, government agencies, and other IUCN members. She has a special fondness for crocodilians.

“I’ve always been fascinated by reptiles in general, and I think the crocodilians are beautiful,” she says. “They’ve been around for so very long, yet we’re still finding out amazing things about them—like they’re more closely related to birds than they are to other reptiles.” Kim and caimans

go back a long way. At the age of 15, she cared for yacare caimans Caiman yacare at the Vancouver Aquarium. She first saw caimans in their native habitat when she traveled to the Amazon with her aquarium team members. More recently, Kim led a SDZWA Adventures expedition to Amazonia. At the Zoo, she oversees the team of wildlife care specialists who care for reptiles, including dwarf caimans Paleosuchus palpebrosus, in Jake’s Cool Critters at Wildlife Explorers Basecamp. At under six feet, the dwarf caiman is the smallest crocodilian.

The order crocodilia includes three families: the crocodiles, the alligators, and the gharials. All 27 species share a

PHOTO BY: KEN BOHN/SDZWA

similar—heavily armored—body plan: a large head with a long snout and toothy jaws, attached to a four-limbed, robust body and long, thick tail. Although some snakes can be longer, crocodilians are the largest living reptiles. Caimans, which live in Central and South America, are part of the alligator family, which also includes the American alligator. “Not every croc is a caiman, but every caiman is a croc,” explains Kim.

Caiman Concerns

While there has historically been heavy exploitation of caimans for their meat and especially their hides, caiman farms (for leather) have largely displaced poaching. But illegal wildlife trafficking is still a problem, as young caimans are targeted for the pet trade. Kim warns, “They don’t make good pets.” Eventually, owners of illegal caimans find that out for themselves. “Occasionally, we get calls from U.S. Fish and Wildlife, when they find a caiman in a pond or a park, to provide care or a home.”

Wildlife trafficking isn’t the only threat facing caimans. “Thinking about climate change, you wonder how it’s going to affect the populations,” says Kim. For crocodilians, as in many reptiles, temperature in the nest determines whether offspring will be male or female—a phenomenon known as “temperature-dependent sex determination.” In most crocodilians, high incubation temperatures produce males, and low temperatures produce females. “What happens if you have all males within a couple of generations?” This is the kind of question that those in the crocodilian conservation community want to be able to address.

Caimans and their crocodilian cousins charm many Zoo guests. “We’re fascinated by them, and we’re a little bit scared, yet there’s a certain affection,” says Kim. “The fact that crocodiles are mummified in Egyptian tombs shows this level of fascination, along with a sort of reverence.” At SDZWA, we are committed to keeping caimans around for a very long time. Studying caimans at the Zoo and in their native habitat helps us better understand them, and how to better protect them.

NOT SO DIFFERENT, YOU AND I

Crocodilians intrigue us, and we have more in common with these reptiles than you might think.

They care for their offspring. Crocs are one of the few reptiles that protect their young until they are old enough to be on their own (almost two years for dwarf caimans). A mother crocodilian threatens or attacks predators that approach too closely. Care begins even before “mama croc” lays eggs, as she mounds up soil and vegetation to make a nest. As the biomatter decomposes, it heats the nest—like a compost pile—and helps keep the eggs warm. Mom settles in nearby to guard her eggs from predators—large birds, lizards, or raccoons—that might try to dig them up and eat them. When her eggs start to hatch, she sometimes gently uses her teeth to help her offspring out of their shells. Then, she carries hatchlings to the water in her mouth. Although juveniles can swim from the time they hatch, sometimes even older offspring get to ride on mom’s back.

They communicate with each other.

Some croc vocalizations sound like rumbling thunder, grunts, barks, or chirps. “The parents, in particular the females, communicate with their offspring, even inside the egg,” says Kim. In fact, even before croc offspring hatch, they vocalize with each other and with their mother, as if to say, “Hey! I could use a little help here!” Like a human baby’s wail, the sound brings the mother running.

They are smarter than you might think.

Crocodilians are considered the most advanced of the living reptiles (meaning they are the least like the earliest reptiles). Wildlife care specialists teach them to approach separate stations for meals, examinations, and health care. They recognize individual people, and they respond to their own names. Kim shares another example. “Crocs are able to change their target mid-strike, something that other reptiles and amphibians can’t do. If a cobra or a lizard is going to strike at something, it is committed when it begins the strike. If the target moves out of the way, the cobra can’t change the strike path, whereas crocodilians can adjust—this shows a higher evolution of brain function.”

PHOTOS BY: (TOP) ADI BAROCAS/SDZWA, (BOTTOM) KEN BOHN/SDZWA

Crocs at the San Diego Zoo

Our Zoo is home to several species of crocodilians. Here’s where to find them.

Discovery Outpost

Chinese alligator

Gharials

Slender-snouted crocodile Siamese crocodile

Critically Endangered Critically Endangered Critically Endangered Critically Endangered

Dwarf Caiman

Least Concern

West African dwarf crocodile

Vulnerable

Reptile Walk, between the Native building and the Turtles building

Discovery Outpost

Aquatic habitat past the Galápagos tortoises, with a variety of large and small turtles

Lost Forest

At the top of Hippo Trail, just off Treetops Way (next to pygmy hippos)

Lost Forest Tiger Trail (near the lower level of Monkey Trails)

Wildlife Explorers Basecamp

Marsh Meadows, lower level of Jake’s Cool Critters

Africa Rocks

West African Forest habitat, with a variety of turtles and fish

Wildlife Explorers Basecamp

Marsh Meadows outside pool

PHOTOS BY: KEN BOHN/SDZWA

Identity Theft

Things aren’t always as they seem in the Amazon. For defense, or to hunt prey, some wildlife mimic other species in appearance and/or behavior. Success equals survival; an individual who deviates from the perfect mimetic form can succumb to predators. Over time, natural selection results in mimics so perfect, they fool even the keenest senses.

By Alyssa Leicht

Illustration by Amy Blandford

While camouflage offers protection by blending in with the surroundings, mimicry is a phenomenon that occurs when an individual looks like a species that is more dangerous or inconspicuous.

This poison dart frog is endemic to Peru and has a wide variety of color morphs. They mimic more toxic species and are only about as large as a thumbnail.

MIMIC POISON FROG Ranitomeya imitator

NUMATA LONGWING

Thanks to a “supergene” and three variations of a single chromosome, the numata longwing can mimic not just one, but seven distinct species of butterflies in the genus Melinaea.

SPHINX MOTH (SNAKE CATERPILLAR)

Hemeroplanes triptolemus

In its larval stage, this moth caterpillar disguises itself like a tree viper by puffing up the area around its head. It even mimics the motion of a snake by striking predators.

Epicadus heterogaster

With a crablike shape and walk, you’d think these spiders were mimicking crabs. Instead, they mimic part of a flower, where they lie in wait to ambush their prey.

The bulging head of this insect, aided by false eye spots, resembles the head of a caiman. The forewings mimic dead leaves, and when lifted, two more eye spots mimic a large vertebrate.

Umbonia crassicornis

The color and hard shell of these insects give them a thorn-like appearance, like you might see on a rose or blackberry bush, offering protection from birds and other predators.

THORN BUG

ALLIGATOR BUG Fulgora laternaria

Heliconius numata

CRAB SPIDER

July and August Hours

San Diego Zoo

9 a.m.–9 p.m.

Extended Hours for Nighttime Zoo

San Diego Zoo

Safari Park

9 a.m.–7 p.m.

sdzwa.org

619-231-1515

*Exceptions apply. Please check our website daily for the latest updates on opening and closing times.

(Z) = San Diego Zoo

(P) = Safari Park

EVENTS

July &

JULY 21; AUGUST 18

Plant Day

On these special days, guests can take a rare look inside the Zoo’s Orchid House (and visit the plant sale) from 10 a.m. to 2 p.m., learn about the Zoo’s botanical collection from Horticulture staff on the Botanical Bus Tour at 11 a.m., and check out the Carnivorous Plant Greenhouse from 11 a.m. to 1 p.m. Free with admission; no reservations needed. (Z)

SAN DIEGO ZOO

THROUGH SEPTEMBER 4

Nighttime Zoo

When the sun sets, your wild adventure is only just beginning during Nighttime Zoo. Visit this summer and you’ll “rock and roar” until 9 p.m. with live music and other amazing specialty entertainment experiences. Stay with us for all the family fun and excitement of Nighttime Zoo! (Z)

JULY 23; AUGUST 13

Member Exclusive

Early Hours

Rise and shine with the sights and sounds of the San Diego Zoo. One Sunday each month, members can enter the Zoo one hour before the general public. To join us, simply present your qualifying membership card at the main entrance beginning at 8 a.m. (Z)

FOR MEMBERS

Wild Perks SM

San Diego Zoo Wildlife Alliance members are eligible for Wild Perks SM . Show your membership card each time you make an on-grounds purchase and save up to 20%, depending on your membership level. Some exclusions apply; for details, visit sdzwa.org/membership/ wild-perks (Z)

DAILY

Journey into the Wild

At 2 p.m. daily in Benbough Amphitheater, our wildlife care team presents the wildlife ambassadors representing San Diego Zoo Wildlife Alliance’s conservation work in our Amazonia Conservation Hub in South America; as well as right here in our own back yard in the Southwest. (P)

SAFARI PARK

AUGUST 12–13

Wild Weekend: Savanna

To celebrate World Elephant Day, join us at the Safari Park to discover the wildlife of our Savanna Conservation Hub with special activities, wildlife care specialist talks, and more. (P)

JULY 23; AUGUST 13

Member Exclusive Early Hours

Rise and shine with the sights and sounds of the Safari Park. One Sunday each month, members can enter the Safari Park one hour before the general public. To join us, simply present your qualifying membership card at the main entrance beginning at 8 a.m. (P)

FOR MEMBERS

Wild Perks SM

San Diego Zoo Wildlife Alliance members are eligible for Wild Perks SM . Show your membership card each time you make an on-grounds purchase and save up to 20%, depending on your membership level. Some exclusions apply; for details, visit sdzwa.org/membership/ wild-perks (P)

Otter-ly a-MAZE-ing!

Giant otters are large (up to 70 pounds!) water-loving mammals with a BIG appetite, chomping down as much as 10 pounds of fish a day. But first, they have to find their food. You can help the hungry otter below as he seeks out his seafood. Go fish!

LAST LOOK

The world’s Amur leopard population got an adorable boost—two, actually—in late March with the birth of a pair of cubs at the San Diego Zoo. Mother Satka is allowing her spotted bundles of joy out of the den, and they can be seen in their habitat in the Zoo’s Africa Rocks. With fewer than 300 of this species left on Earth, every addition is a cause to celebrate.

Photographed by Ken Bohn, SDZWA photographer.