Kerry Holcomb marveling at the succulent to dry Karoo transition zone, Northern Cape, South Africa.

Kerry Holcomb joined the Desert Tortoise Recovery Office in February as a Recovery Biologist. Over the last 11 years, Kerry worked as a wildlife biologist for The Great Basin Institute and U.S. Fish and Wildlife Service in the desert southwest, primarily with Mojave desert tortoises, and has over a decade of experience managing biological resource studies and scientific research projects for a variety of species. Originally from Georgia, he earned a Bachelor of Science in Wildlife Ecology from the University of Georgia’s Daniel B. Warnell School of Forestry and Natural Resources, and a Master of Science in Biology, with an emphasis on ecophysiology, from the University of Central Washington. Kerry is working from the Palm Springs Ecological Services Field Office in Palm Springs California.

He has since been involved in research to quantify the impact of common raven predation on 0- to 10-year-old Mojave desert tortoise survival, index tortoise exclusion fence priorities, and, in partnership with the Cornell Wildlife Health Lab and Geological Survey’s Western Ecological Research Center, develop two software packages to empower land managers to design effective and defensible raven population management goals and strategies.


Corey Mitchell joined the Desert Tortoise Recovery Office in January as Desert Tortoise Monitoring Coordinator. Over the last 15 years, Corey worked as a wildlife biologist in the desert southwest, primarily with Mojave desert tortoises, and has over a decade of experience managing biological resource studies and scientific research projects for a variety of taxa.

Corey Mitchell releases a desert tortoise fitted with a tracking transmitter.

Originally from Wisconsin, she earned a Bachelor of Science in Zoology from the University of Wisconsin, Madison, and a Master of Science in Geography from the University of Nevada, Reno. For her thesis research, Mitchell used quantitative ecology approaches and spatio-temporal data to study population ecology and improve density estimation for the Mojave desert tortoise. She was involved in research on quantifying the climatic and environmental drivers of reproductive output for the Mojave desert tortoise and developing software to map and disseminate wildlife disease surveillance results to aid wildlife management and disease monitoring efforts for the Cornell Wildlife Health Lab.

Initially interested in studying primate behavior, she worked with four species of primates on three continents. Corey is working from the Arizona Ecological Services Field Office in Tucson, Arizona.


Retiring: Flo Deffner, desert tortoise recovery biologist, Southern Nevada Fish and Wildlife Office 

Deffner conducts a health assessment on a captive Mojave desert tortoise.

Flo will be retiring from the Service on December 31, 2022. Flo has been a recovery biologist with the Desert Tortoise Recovery Office at the Southern Nevada FWO since 2016. She began her career with the Service as a STEP Intern at the Bon Secour NWR in Gulf Shores, Alabama. From 2009 to 2016, Flo was a senior biologist at the Sacramento FWO, where she worked on Section 7 Section 7
Section 7 Consultation The Endangered Species Act (ESA) directs all Federal agencies to work to conserve endangered and threatened species and to use their authorities to further the purposes of the Act. Section 7 of the Act, called "Interagency Cooperation," is the mechanism by which Federal agencies ensure the actions they take, including those they fund or authorize, do not jeopardize the existence of any listed species.

Learn more about Section 7
consultations for the California High-Speed Rail Project. In an effort to address threats posed by transportation infrastructure on tortoise recovery, Flo organized a workshop and formed a task force. She also produced a documentary that highlights transportation ecology issues that affect tortoise recovery ( ). Flo collaborated with Service and BLM biologists to conduct studies monitoring the use of culverts by desert tortoises and incorporated the use of citizen science through the Road Warriors Project she developed with Tortoise Group. She coordinated with the Center for Large Landscape Conservation, Western Transportation Institute, and Tortoise Group to customize the ROaDS app for recording observations of Mojave Desert fauna, with particular focus on desert tortoise observations and raven activity along roads. Flo has worked with Tortoise Group to address captive tortoise issues and organizing health assessment clinics for captive tortoises. Flo and her husband Dave recently relocated to Gulf Shores, Alabama, where they plan to spend their retirement enjoying the beautiful white sands and clear gulf waters, while participating in local efforts to protect and conserve the incredible biodiversity of their new home.


Kristina Drake examines with a wild Mojave desert tortoise.

Kristina Drake, Ph.D. joined the Southern Nevada Fish and Wildlife Office/Desert Tortoise Recovery Office as the Mojave Desert Tortoise Recovery Coordinator in Las Vegas, Nevada. She came on board in November 2022.

Kristina earned her doctorate in ecology jointly from the University of California-Davis and San Diego State University, and a M.S. and B.S. in biology from Georgia Southern University. She is a life-long turtle enthusiast and has 26 years of experience as a tortoise biologist.

Drake worked as a biologist and researcher for the U.S. Geological Survey, Western Ecological Research Center since 2004, developing programs to better understand habitat and wildlife populations in the southwestern U.S., with particular interest in Mojave desert tortoises. She also served as a co-instructor for the Service’s desert tortoise health assessment training course and worked with many partners in the broader tortoise community to address monitoring, recovery, and conservation issues that impact tortoises and habitats in the Mojave Desert.


Representatives of the Southern Nevada Agency Partnership (SNAP) set up shop at Nellis Air Force Base on November 4-6, 2022, during the annual Aviation Nation spectacle on the base.

Read about the event here:


Scientists counted 175 Devils Hole pupfish, which is the most they’ve observed in a spring count in 22 years. This momentous count also marked the 50th anniversary of counting pupfish using SCUBA, dating back to April 6, 1972.

Read more here: News Release-Spring Count of Devils Hole pupfish

The Devils Hole pupfish count caught the attention of the Los Angeles Times. Read the article here


Dedicated to recovering the desert tortoise

Roy Averill-Murray and his quest to help this iconic species. Read about it here:


Mesquite Tree Mystery

The Service and The Nature Conservancy are trying to solve a case of dying mesquite trees in Nye County. Read about it here:


Desert Tortoise Survival

The U.S. Fish and Wildlife Service, the U.S. Geological Survey, the Bureau of Land Management, and the National Park Service, are working to defend the tortoise and its Mojave Desert home from invasive grasses. Hear from the biologists working in the southern Nevada desert what the threats are to the desert tortoise and how you can help. Watch the video here:


The Buckwheat and the Butterfly

The "buckwheat and the butterfly” may not sound like a match made in heaven, but the Spring Mountains dark blue butterfly depends heavily on this yellow, flowering plant from birth until new eggs are laid the following season. Learn more here:


Pahrump Poolfish on the Brink of Extinction

There is a rare species of desert fish fighting for its survival in a fresh water pond in the desert landscape of southern Nevada -- the Pahrump poolfish. One of the last remaining populations of the endangered Pahrump poolfish, Empetrichthys latos, is at an alarmingly low number, below 1,000, compared to the 10,000 recorded in 2015. Throughout the month of October 2016, U.S. Fish and Wildlife Service biologist James Harter and Nevada Department of Wildlife biologist Kevin Guadalupe are rescuing the Pahrump poolfish from Lake Harriett at Spring Mountain Ranch State Park outside of Las Vegas, Nevada, and moving them to the Nevada Department of Wildlife’s fish hatchery at the Lake Mead National Recreation Area. The poolfish are being taken to the hatchery to protect the species from extinction. According to Harter, it is the Service’s intention to “maintain what population currently exists.” The inter-agency team will then drain the water in Lake Harriet and remove any non-native plant and animal species. The goal is to restore the lake to its original condition before reintroducing the Pahrump poolfish back to the wild. For more on this subject, click here:


Team wraps up five-year bird-banding effort in southern Nevada

U.S. Fish and Wildlife Service personnel recently completed the fifth year of banding migratory birds on the Moapa Valley National Wildlife Refuge as part of a project to assess the overall status of birds that migrate to southern Nevada to breed and their use of habitat on and adjacent to the refuge. For more about this effort, click here:


Moapa dace numbers are trending upward

The most recent count of Moapa dace showed some good signs for the endangered fish. Find more information here: