Conserving reptiles — and training troops – in the Mojave Desert

BY JODI PETERSON

The arid Mojave desert sprawls across roughly 50,000 square miles, mostly in southeast California and southern Nevada. A scrubby landscape of creosote bush and saltbush, it’s dotted with dry lake beds and Joshua trees. Several rare species of wildlife live here, including the western pond turtle and the Mojave desert tortoise. These reptiles thrive in habitat free from development and human intrusion — and they find it on the Mojave’s vast military bases.

Edwards Air Force Base, in southern California on the desert’s western edge, holds a surprising oasis: a 5,000-acre complex of wetlands, marshes, and ponds known as Piute Ponds. A group of western pond turtles lives here, a relic of wetter times; ongoing drought has wiped out other populations in the area. The species has existed basically unchanged for at least 12 million years.

The Piute Pond population was first discovered in 2014 and has been studied ever since by Colorado State University’s CEMML and the Edwards AFB natural resource program, working with the U.S. Geological Survey. “Edwards is very proactive about managing natural resources,” said Alison Haigh, a CEMML wildlife biologist who studies western pond turtles. “They like to have baseline data on sensitive resources so they can be prepared for future changes.”

From 2019 to 2024, CEMML conducted a 5-year study of Piute Ponds turtles using traps and radio telemetry. Elusive and shy, western pond turtles are difficult to study. “We captured a lot of turtles in traps the first two years,” said Haigh. “But they got trap-smart very quickly.” The study revealed that the turtles at Piute Ponds are actively reproducing. More work is needed to understand where they nest and how they use upland habitat, Haigh noted, so those sites can be protected. The team also did eDNA testing, analyzing water from ponds in turtle habitat to learn more about the population’s genetic origin.

The study results provide a baseline for pond turtle management at Edwards AFB; they also may help the U.S. Fish and Wildlife Service assess the status of pond turtles in the Mojave Desert, since they have been proposed for listing under the Endangered Species Act.

The Mojave’s other chelonian species, the desert tortoise, is protected as threatened by the states of California and Nevada; it’s also listed federally under the Endangered Species Act. In June 2025, California upped the tortoise’s status to endangered.

These iconic reptiles, with their domed, patterned shells, have inhabited the Mojave’s harsh landscape for 15 million years. But since 1984, populations have plummeted by 90%, due to development, roads, invasive species, wildfire, drought, and predation by ravens and coyotes.

The tortoise is a keystone species whose presence indicates ecosystem health; when it disappears, other desert species are suffering as well. One of the many benefits that tortoises provide is ecosystem engineering. They excavate about a dozen burrows each year, and their abandoned tunnels shelter snakes, birds, and small mammals. Their earth-digging also helps redistribute seeds, nutrients, and biomass.

On the Nevada Test and Training Range and Nellis Air Force Base in southern Nevada, CEMML and the Nellis natural resources program are working on a new long-term monitoring effort to gather more complete data about desert tortoises. Previously, tortoise abundance was estimated through transect surveys, which involved walking a line and documenting all tortoises found.   However, the animals are notoriously hard to spot, since they spend most of their time in underground burrows to escape heat and predators.

Now, CEMML biologist Drew White-Jacobson is leading the use of a new method — demographic plots, in which several observers walk every inch of a large square plot for 3 days in a row. The unique ID number of each tortoise spotted is recorded, if the animal already has a tag; if not, one is affixed. The tortoise’s sex and condition are also noted, vital information not captured with a transect survey. The intensive effort of a plot survey makes it likely that every tortoise in the plot will be recorded, even the young ones. “On a transect survey, you have a very low probability of finding juvenile tortoises,” said White-Jacobson. “They’re the size of a hamburger, they look like a rock, and they don’t move much.”

The most recent plot survey, in October 2025, did not locate any tortoises on NTTR, but found 5 adult tortoises on the Nellis Small Arms Range. Several CEMML employees participated (no federal employees could join them due to a government shutdown). “It’s thrilling to bring together a large community of people who are passionate about tortoise conservation and to see the incredible amount of interest, grit, and dedication they have,” White-Jacobson said.

The conservation of western pond turtles and desert tortoises aids Edwards and Nellis in successfully carrying out their military missions. “The Mojave is a great analog to military combat terrain in the Middle East,” said White-Jacobson. “When we maintain healthy habitat for the desert tortoise in the Mojave, we are also supporting the use of that terrain for training exercises.” Improving western pond turtle habitat also provides erosion control, water storage, and beneficial conditions for other sensitive species. These turtles occupy ponds, streams, and wetlands that are already protected from training impacts under various military requirements.

“Coexisting with endangered species is an inherent part of the military mission,” added White-Jacobson. “The more information the military has about the status of desert tortoises and western pond turtles on their lands, the better they can make good decisions for both training activities and the environment.”