Slow but Steady:  Desert Tortoise Recovery

Watching expectantly for an animal that spends 98% of their time in a burrow might seem like a futile endeavor, but spring has sprung, and in this case, the wait at the Desert Tortoise Conservation Center (DTCC) is worth the effort.

Desert tortoises, found throughout the Mojave and Sonoran Deserts of California, Nevada, Arizona, Mexico, and Utah, were listed as a threatened species in 1989. Across their range, tortoises are found at very low densities, even in formerly heavily occupied areas. Key factors contributing to their decline include disease and development. In partnership with the U.S Fish and Wildlife Service, the U.S. Bureau of Land Management, and the Nevada Department of Wildlife, San Diego Zoo Global operates the Desert Tortoise Conservation Center. 

The DTCC is situated within an 11,014-acre management area representing one of the last large, intact tracts of natural desert habitat in the Las Vegas Valley. It temporarily holds formerly wild and pet tortoises (either removed from the path of development or unwanted), and provides a hub for training and scientific work focused on disease, husbandry, nutrition, and reintroduction back to the wild.

It’s my first trip to a parched land where the scenery is hot and prickly to the touch.  I’ve driven to the Mojave Desert to discover more about the rocky road to recovery facing the threatened Mojave Desert tortoise. Getting out of the car, the heat feels unforgiving, and through the settling dust of the dirt road, a cascade of questions spring to my mind. Where did I pack my sunscreen?  What is happening to the Mojave population of the desert tortoise? Has the threat of disease been satisfactorily abated? Has loss of habitat been slowed and degraded lands restored to improve animal health and productivity? Are reintroductions of tortoises monitored and improved upon to advance the recovery process? I have a hunch the San Diego Zoo Global team will help me find the answers…and my sunscreen.

Walking around the Center, exemplary care, recovery based research, and training efforts are evident. Research Coordinator Angie Covert highlights recent improvements to living conditions and veterinary care.  Our pathology postdoctoral fellow, Josephine Braun, is correlating clinical signs, pathologic lesions, and diagnostic test results to identify the criteria that best predict which tortoises are most suitable for release to the wild. 

Recently, Angie explains, we conducted our first hands-on health assessment training for biologists working on solar development sites in the Mojave Desert. Feeding the tortoises in the early morning sunshine, I notice that Marisa, one of the Research Associates caring for the tortoises, has pink shoe laces on. She says that the tortoises are attracted to pink flowers in the wild and as she walks among them parsing out tortoise chow, they follow her pink footsteps.

Last year we repatriated over 500 tortoises into protected areas. Accompanying Jennifer Germano, postdoctoral researcher, into the wilds of Nevada, I hope to find out how some of the translocated animals are faring. Dusty, sunburned, and thirsty after two hours of hiking and radiotracking our targets, I wonder aloud how far can a tortoise possibly travel? Jen recounts the story of Hillary, no ordinary tortoise. Hillary ran off the moment she was translocated and, living up to her name, took 10 days to climb to the top of a mountain. After 10 days of climbing after her, to Jen’s surprise Hillary came back down in just one day!

By evening, I have my own love story to tell. Locating one male snuggled up in a burrow with two females (one with a radio tag and one without) seems a clear indication that our translocated animals are faring well and successfully striking up relationships with the locals.

Looking around the Center one last time before I hit the road to San Diego, I’m struck by all the possibilities and answers this place holds. As a facility for the refinement of reintroduction techniques, we can assist in augmenting areas with low population densities and bolster tortoise recovery. It is also a place where public and private biologists are trained in the safe and proper handling of tortoises, ensuring standard data collection practices and guaranteeing a new generation of tortoise experts. By expanding our outreach capacity, we can educate many more visitors, students, and teachers about what they can do to help. 

Our vision is to transform the DTCC into a world-class facility to support research and education not only for the desert tortoise, but also for the Mojave Desert as a whole.  For now, I am assured that slowly but steadily, we are assisting recovery of this iconic species and keeping the desert ecosystem functioning. It is good to know that there is still much more we can contribute.

Allyson Walsh, Ph.D., Associate Director, Applied Animal Ecology