7 minute read
A Look Back At What Park Researchers Have Accomplished
By Jillian Petersen, Environmental Services Intern with Colorado Desert District
As a desert lover reading this magazine, you may have wondered what occurs behind the scenes at Anza-Borrego Desert State Park (ABDSP). Many of us have been to the Visitor Center, where staff and volunteers interpret information about the Park and share the best places to see wildflowers or go on a four-wheel drive tour. You may not realize however, that park scientists, university researchers and volunteers are constantly studying the biological, geological, archaeological and paleontological resources in the Park. These ecologists, GIS (Geographic Information Systems) specialists, paleontologists and archaeologists work hard to understand, monitor and protect the resources of our beloved desert. They are responsible for collecting scientific data and using it to make informed conservation decisions that preserve the land, flora, fauna and history for future generations.
And it's more than just the Anza-Borrego desert where they work! This small team of scientists work in the two mountain parks that are part of the Colorado Desert District - Cuyamaca Rancho State Park and Palomar Mountain State Park. Accordingly, this team of dedicated scientists must strive to understand the relationships or 'connectivity' that exists between these geographically-related parks.
A summary of some of the research they've conducted over the past year follows. We are thrilled to be able to work as a team and share insights with visitors and desert lovers like you!
Flat-Tail Horned Lizards (Phrynosoma mcallii, "flat-tails") Surveys
Flat-Tailed Horned Lizards (Phrynosoma mcallii, "flat-tails") camouflage themselves by flattening their bodies to the ground and eliminating any possibility of creating shadows. They are hard to spot but we are completing another successful season of surveys in ABDSP. ABDSP is a founding member of the Flat-Tail Horned Lizard Interagency Coordinating Committee (FTHL ICC) and continues to participat in integrated rangewide surveys for the lizard. The FTHL ICC coordinates conservation efforts for this lizard, the rarest horned lizard species with the most restricted range and a Species of Special Concern in California. The surveys aim to assess where flat-tail habitat is located within ABDSP on the northwestern edge of their distribution. Our survey team sets out in the summer heat to designated plots to search for these lizards daily. Starting around sunrise, the survey team spends up to an hour on a visual identification survey, walking back and forth within the plot. If a flat-tail is found, the team will measure the lizard's length and mass, determine the sex, and then let it go. During the 2022 season, we found 30 individual flat-tails, and we are looking forward to seeing how many we find by the end of this summer survey season. Rainfall, harvester ant populations, ground vegetation cover and temperature could all factor into how many flattails we see yearly.
Least Bell's Vireo (Vireo bellii pusillus) & Western Yellow-Billed Cuckoo (Coccyzus americanus) Surveys
Over the summer, ABDSP Natural Resources teams conducted ongoing surveys for the federally endangered least Bell's vireo (Vireo bellii pusillus) and federally threatened western yellow-billed cuckoo (Coccyzus americanus). The least Bell’s vireo is a shy songbird that used to be one of the most abundant birds in North America; the yellow-billed cuckoo is a tall bird that blends in with the trees and has declined with its habitat. Both species are listed under the Endangered Species Act primarily due to loss and degradation of woody riparian ecosystems (trees and shrubs growing along rivers). Our surveys of these two species help evaluate their populations and identify occupancy trends. Surveys were conducted
following trails through riparian areas. Survey teams follow defined protocols to listen, look for, and record behavioral data on the vireos and cuckoos, which could include singing, calling, nesting, foraging, etc. Cuckoos were thought to only migrate through ABDSP, but this year's survey results suggest they may have nested here over the summer.
Invasive Plant Removal
Our Botany team has been working hard to defeat invasive plants. We have focused on eradicating Egyptian knapweed (Volutaria tubuliflora), and ABDSP Botany Society volunteers assisted in weeding Sahara mustard (Brassica tournefortii) in various areas around the Park. Volunteers
completed training courses to become experts in plant identification, life cycles and seed-spreading mechanisms, and joined in weeding events with the Park. During the spring, volunteer members of the Sierra Club and the University of Virginia Alternative Spring Break also joined us on separate occasions to assist ABDSP teams in weeding Volutaria, Sahara mustard, and tocalote (Centaurea melitensis). Our botany team has also collected plant specimens and identified some rare plants in the district! The Botany Society starts work again in January. If you are interested in volunteering, please get in touch with Parks staff for more information.
Sentenac Cienega Symposium
In December, ABDSP and partners participated in the two-day Sentenac Cienega Symposium hosted by the Anza-Borrego Foundation, which invited the public to learn about current research and recommendations for restoring the desert wetland ecosystem. Over the past few years, researchers from Parks, University of San Diego (USD) and the University of California, Irvine (UCI) collected ecosystem data on vegetation, aquatic invertebrates, amphibians, birds, mammals, hydrology, climate and the cultural significance of Sentenac Cienega. Researchers presented their findings and fielded questions about their survey work and results at this symposium. Participants also had the chance to participate in a State Park and researcher-led site visit to the project area to learn about the local ecology, including tree canopy health, channelization of the creek, efforts to control invasive plant populations and much more.
Paleo Sieving Station
ABDSP Paleontology teams completed the construction of the paleo sieving station, which will be used to wash and sort through hundreds of pounds of fossiliferous sediment gathered from field research locations within our parks. This sieving station will make collecting and identifying small fossils hidden in sand formations and examining them under microscopes significantly easier. The Paleontology team and Paleo Society volunteers regularly survey ABDSP locations for fossils and fossil formations, which can be collected, cleaned, repaired, and cataloged into our extensive Paleontology library and Research Center. Paleo Society volunteers also hosted a series of presentations about camels, horses, the evolution of birds from dinosaurs and what fossils tell us about ecosystem changes over the last 4 million years.
