My life as a field biologist finally seems to have slowed down as of late. With the cold weather settling in here in the Mojave Desert and the desert tortoises all hiding deep in their burrows, I finally have a chance to reflect back on my first year here working as a researcher for the San Diego Zoo’s Desert Tortoise Conservation Center in Las Vegas, Nevada. I’ve spent the past 12 years of my life studying amphibians and reptiles both around the country and throughout the world. But I must admit, chasing turtles and lizards in tropical rain forests or frogs on tiny islands in the South Pacific did not quite prepare me for working with these iconic desert creatures.
At first I thought, “Desert tortoises: how hard can it be?” After years of searching for silent frogs the size of an Oreo cookie in a dark forest at night, finding a tortoise the size of a dinner plate in a wide-open desert should be a piece of cake, right? And really, how fast can a tortoise possibly move? We’ve all grown up with the story of the tortoise and the hare…and yet even as a trained herpetologist, I was about to be amazed.
Jennifer radio-tracks translocated desert tortoises in southern Nevada.
Desert tortoises have adapted remarkably well to their arid environment. Despite, and perhaps because of, their size, they blend in with all the other rocks and rubble on the desert floor. Even with a radio transmitter glued to their shells, I’ve walked by more than a few, only to turn around to see their little faces peering at me from under their shell, hoping that I would keep on walking and mistake them for a another rock in the sunlight.
And as far as running? Well, tortoises may not be as fast as a hare, but they can definitely move. Currently, as human development takes over more and more of our pristine desert habitat, animals like the desert tortoise are often translocated or moved out of harm’s way. Unfortunately though, when you move a tortoise and drop it Bear Grylls-style into unknown territory (well, maybe not quite Man Vs. Wild style, as we do place our animals carefully in new sites and don’t make them jump out of airplanes and boats), the tortoise runs. Maybe not as fast as a cheetah or a Boston marathoner, but in true tortoise fashion they get their little legs going and race off.
This has been one of the focuses of my research: to figure out what affects an animal’s drive to move and how they behave following a translocation. After all, when we move animals out of harm’s way and to a safe place, we don’t want them to run home or leave the safety of our release site after translocation. Besides that, running takes an awful lot of energy, and if you are a creature adapted to the unforgiving desert environment, you want to conserve as much energy and food resources as possible.
Hillary, one of our translocated tortoises, comes down from the mountain (behind her) that took 10 days for her to climb.
Over this past year, I have spent countless hours trekking through the desert chasing after our tortoises to see where they went. One of them, Hillary (named after Sir Edmund of Mt. Everest fame), ran off right after the translocation and, living up to her name, took 10 days to climb all the way to the top of a mountain, stopping only at the base of a sheer cliff. After 10 days of climbing the mountain after her, to my great relief Hillary came back down and returned to the desert floor, settling in a wash only a few hundred yards/meters away from where we released her. Kenya, another of our amazing desert tortoises, spent the first few weeks after the translocation making daily movements of nearly a half mile (kilometer) or more. This is no small feat for a tortoise! With their tiny little legs, this would be like us walking over 10 miles (15 kilometers) a day!
Besides these amazing feats, surviving in the desert in a completely unknown area following a translocation is an accomplishment in itself. Most of our tortoises have stood up to the challenge and have made it through their first eight months at the new translocation site. While my team and I returned to our trucks at the end of each day, often sunburned and parched after hours of radio tracking, our desert tortoises have soldiered on. With hardly any rain and temperatures that soar to over 110 degrees Fahrenheit (43.33 degrees Celsius), these tough little critters survive and thrive in an environment that would put most of the staunchest humans to shame. It’s not an easy task, but I hope the knowledge we gain from our research will help to make future translocations at least a little bit easier on these resilient critters. It’s a tough life out there in the desert, and they deserve all the help they can get.
Jennifer Germano is a postdoctoral researcher at the San Diego Zoo Desert Tortoise Conservation Center.