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desert tortoise conservation

1

Tortoises: Into the Wild

Each released desert tortoise had a radio transmitter fixed to its carapace with epoxy.

Each released desert tortoise had a radio transmitter fixed to its carapace with epoxy.

It began early in the morning, before the sun peeked over the mountains. The Desert Tortoise Conservation Center (DTCC) in Las Vegas was abuzz with activity as we prepared 32 desert tortoises for the journey of a lifetime. Little did these animals know that they were about to be brought to a new home. Many of them had been living at the DTCC for several years; some had even begun their lives as pets. Now, these tortoises would be released into the wild to try to help bolster the native populations as well as give them the chance to live their lives as wild tortoises.

When the tortoises were ready, we carried each to a preset location and placed it in a sheltered spot under a shrub.

When the tortoises were ready, we carried each to a preset location and placed it in a sheltered spot under a shrub.

After placing the tortoises in hay-lined totes, we loaded them into trucks and headed to Trout Canyon, a beautiful piece of Mojave Desert habitat over the mountains to the west of Las Vegas. Once on site, the tortoises were administered fluids to help them stay hydrated in the first weeks in their new home. We double-checked the frequencies of each tortoise’s radio transmitter to ensure we would be able to track them in the field over the coming weeks and months.

We watched the tortoises for several minutes after releasing them to see how they reacted to their new environments. As you might expect, many of them were reluctant to move for a little while, but some took to walking and started exploring their new home right away!

In the four weeks that have passed since the translocation, we’ve tracked the movements of all 32 tortoises we released, as well as 20 tortoises that were already living there. Some tortoises have stayed relatively near their release sites, exploring only about one or two football fields’ worth of the new neighborhood.

Caliche caves can act as rock burrows for tortoises, protecting them from predators and the elements.

Caliche caves can act as rock burrows for tortoises, protecting them from predators and the elements.

Shelter is a prime concern for tortoises, as they need to protect themselves from extremes of temperatures (both hot and cold) and from would-be predators like coyotes or ravens. Many of the tortoises we released have found temporary shelter under shrubs like creosote or white bursage and continue to move around in a relatively small range.

A few tortoises are taking up residence in existing burrows near their release site. The burrows may be abandoned or are occupied by accommodating neighbors. When suitable unoccupied burrows are unavailable, a few industrious tortoises have begun to dig their own.

Other tortoises have taken up shelter in caliche caves. One of the tortoises found the nearest cave to its release site and stayed there for over two weeks. Then, one day, he decided to start moving and has been walking for the past few days about a third of a mile (half a kilometer) a day.

We have tracked other tortoises traversing the landscape walking miles away from their release sites. They have covered rough terrain from windy creosote flats to rocky washes and steep mountain ridges. The end of the spring growth has provided some forage for the tortoises, and they need to take advantage and gather resources now before the heat of summer dries up the best nutrient sources.

We found a desert tortoise egg just outside a burrow.

We found a desert tortoise egg just outside a burrow.

Although the race is still on for who has traveled the farthest, one tortoise in particular has certainly moved with a purpose. She scaled steep rocky ridges and deep washes only reach the top and decide to cross the next ridge to the north. After weeks of walking, she finally took a few days off to rest. Apparently she had a mission in mind, as today we found her nesting under a blackbrush on a steep mountain ridge. She had already laid one egg; we could see it just outside the burrow!

The next few weeks will be important for the tortoises as the females continue to nest and they all settle in for the heat of summer, when they will only be active in the coolest parts of the day. Finding or building burrows in the soil or rocks is very important, as is foraging. A good rain or two would help bolster their water supply for the season, but we can only wait and see what the weather brings!

Ben Jurand is a research associate at the San Diego Zoo’s Desert Tortoise Conservation Center. Read his previous post, Time for Tortoise Training.

4

Time for Tortoise Training

Ben prepares to take a blood sample from a desert tortoise.

Ben prepares to take a blood sample from a desert tortoise.

The Desert Tortoise Conservation Center (DTCC) in Las Vegas, Nevada, is gearing up for the spring translocation of a number of desert tortoises. We will be moving tortoises from the DTCC to a field location in the desert, where we will release them to help augment struggling wild populations.

Translocation is stressful on tortoises, because they need to adapt quickly to new surroundings, find shelter, and keep a lookout for both resources and predators. To give translocated tortoises the best chance of surviving in the wild, we need to make sure the animals are healthy and strong enough to be released. We also need to try to prevent them from spreading diseases to other tortoises in the wild.

As a new research associate at the DTCC, my first week included a lot of training. We were lucky to have several desert tortoise researchers and veterinarians visit from the U.S. Fish and Wildlife Service and San Diego Zoo Global to provide hands-on instruction on how to visually assess the health and condition of tortoises. We also learned how best to gather data and collect samples, including how to take oral and blood samples from the tortoises to test for diseases. We learned how to measure the size and weight of each tortoise, made notes about how their facial features and shells looked, and checked them for injuries or signs of illness.

DTCC staff take desert tortoise measurements.

DTCC staff take desert tortoise measurements.

Knowing their condition before we move them will help us track their progress over time in their new wild habitat. On some of the tortoises, we will be attaching radio transmitters to the upper part of their shell (called a carapace). After we have translocated the tortoises, we’ll be tracking their movements in the field and will monitor their health conditions in the days, weeks, and months ahead.

It is our hope that by continuing these studies, we will get a better understanding of how translocations affect the desert tortoises we move as well as their new tortoise neighbors.

Ben Jurand is a research associate at the San Diego Zoo’s Desert Tortoise Conservation Center.

1

Tortoises Spotlight Teacher Workshop

Workshop participants find a “tortoise” using radio-tracking equipment.

As we close in on our winter season at the Desert Tortoise Conservation Center, located in Las Vegas, Nevada, it’s a great time to reflect on some of the highlights of our busy summer. One new program we offered to local teachers through the Clark County School District was a desert tortoise education workshop. This past June and July, a total of 32 teachers took part in the workshops. We’re happy to report that the classes were well received, and the response has been very positive!

Although rarely seen in the wild, the desert tortoise is the state reptile of Nevada and an important keystone species of the Mojave Desert ecosystem. Getting kids excited about science and math can be a huge hurdle for many teachers, and this was one of our main motivations for developing the desert tortoise workshop. One of the goals of the workshop was to provide teachers with curriculum that spotlights the cool adaptations of the desert tortoise while focusing on the important roles it plays in the Mojave Desert. With a focus on biology, ecology, and conservation, teacher participants were provided with fun and interactive desert tortoise curriculum, which also fulfills the Nevada classroom standards in life and earth sciences.

Throughout the workshop, teachers became students and were able to participate in hands-on activities and demonstrations to simulate current research projects being conducted by San Diego Zoo scientists. For example, teachers participated in a telemetry demonstration, learning hands-on how researchers use telemetry to study tortoise behavior following a release back into the wild. As a part of the activity, participants used radio tracking-equipment to “track” a model tortoise (made of Styrofoam), which had been affixed with a radio transmitter and hidden under vegetation. It was fun to watch a group of educators weave their way through the desert in unison, following the sound of a radio receiver, which released a “ping” as the Styrofoam tortoise grew closer.

Educators who participated in the workshop earned one credit toward professional development education through the Clark County School District, and were provided with desert tortoise resource materials and activities, which can be adapted to their individual grade levels. After a successful first run, we will be offering the workshop again to local teachers in February 2013. We’re excited to provide educators with the opportunity to study the desert tortoise and return to the classroom with a range of tools to promote continued education of this amazing animal and the Mojave Desert ecosystem.

Lori Scott is a research associate at San Diego Zoo Global’s Desert Tortoise Conservation Center. Read her previous post, Desert Tortoises Pose for Photos.

8

Wandering Males, Jealous Boyfriends

Jeanette removes a transmitter from one of the released desert tortoises.

We’re currently at the tail end of one of our desert tortoise translocation projects. It’s finally time to say goodbye to the desert tortoises we have been tracking for the past year and a half, and over the past month or so we’ve begun the task of removing their transmitters. However, this is easier said than done. This project happened to end during the mating season, a time when males move long distances in search of females. One of our males went missing for five weeks and was found almost three miles from his old burrow!

Before we remove the transmitters, we do a final health assessment. We noticed damage to the underside of the carapace (the top shell) on many males. They are known to fight other males utilizing their gular horns to attempt to flip their opponent onto their back. Some male tortoises are bolder than others, and we came across a very bold resident male searching for a female one sunny morning. As my coworker, Jason Rose, and I approached a burrow that female tortoise #619 was occupying, we heard movement inside the burrow. Assuming it was the female we were tracking, we checked the burrow and saw a male tortoise charging at us! He came straight out of the burrow and blocked its entrance, trying to keep us away from his mate. His chin glands were enlarged, and he looked mad!

Here is tortoise #619′s very ardent and determined suitor.

Jason put some gloves on and moved him 50 meters (165 feet) from the burrow so we could get to the female. While waiting for the female to come out of the burrow, the male snuck up behind us and attempted to re-enter the burrow. This time we moved him 100 meters (328 feet) from the burrow to give us some time with the female. Moments later, the male returned and charged Jason. Knowing the female was not going to exit the burrow with the aggressive male in the area, we packed up and allowed the male to re-enter the burrow. He positioned himself facing toward us, in front of the female. Claiming defeat to the jealous boyfriend, Jason and I left the site.

Jeanette Perry is a research assistant at San Diego Zoo Global’s Desert Tortoise Conservation Center in Las Vegas, Nevada.

1

With a Little Help from Our Friends

Boy Scouts Orlando Arnold, Jr. and Cory Chatterton are hard at work making artificial burrows for our tortoises.

I’ve spent over 10 years working in conservation, and no matter where in the world you end up, whether it’s here in the States, down in South America, or halfway around the world in New Zealand or Australia, one thing is painfully clear: there’s a lot of important conservation work that needs to be done and there never seems to be enough resources to get us to where we want to be. Though the budget shortfalls sometimes make the work a bit more difficult, one area in which I’ve been repeatedly amazed is the great support we often receive from members of the community and enthusiastic folks who come out and donate their time and a bit of sweat helping us get our work done. Conservation and the science behind it is not a solitary endeavor. Many people go into making every project succeed, and I just wanted to take this opportunity to remind all of you who may have helped with a conservation project (with San Diego Zoo Global or otherwise) or are thinking about volunteering that your time and enthusiasm really do make a huge difference!

Volunteer Simon Madill works on some fence repair for our on-site tortoise research.

Here at the Desert Tortoise Conservation Center in Las Vegas, spring is standing on our doorstep, and we’re all preparing for the start of a new field season. Our research team is getting ready to embark on some new projects here on site, one of which required us to fix up some old tortoise pens that had fallen into disrepair over the past 10 to 15 years. This was a HUGE undertaking and one that would have taken me months of digging artificial burrows and fencing ditches as well as updating and fixing the fences for over 20 100-foot-long pens. A couple of months ago I was beginning to wonder how I was ever going to get it all done and if we’d have anywhere to put our tortoises in the spring. But the world works in mysterious ways, and just in the last month we’ve had some amazing volunteers lend a hand.

Members of the Nevada Conservation Corps after two days of fixing fences in our experimental tortoise pens.

Troop 336 with the Boy Scouts of America, Las Vegas Area Council, led by Cory Chatterton, some members of the Nevada Conservation Corps, and one of our long-term volunteers, Simon Madill, came to my rescue. Nearly 40 people came out over several days, and after some long hours of swinging shovels and pick axes in the desert sun and hours of cutting and tying up fencing, we have finally finished 20 tortoise pens!

All the enthusiasm and hard work of our volunteers mean that this spring we are able to start our tortoise behavior study. I am hopeful that the things we learn will help to improve our future reintroductions of animals back into the wild.

Jennifer Germano is a postdoctoral researcher at the San Diego Zoo Desert Tortoise Conservation Center. Read her previous post, Tortoises and Their Amazing Feats.

2

Bacteria, Viruses, and Disease, Oh My!

One of the many perks of working for San Diego Zoo Global is the opportunity for professional development. I recently got back from one such occasion and thought a change of pace might be nice, especially for you virology types!

I spent the past month in Escondido, California, at our Beckman Center in the Wildlife Disease Labs (WDL) under the instruction of my co-manager, Josephine Braun, D.V.M., a pathologist, veterinarian, and protector of the universe. She periodically sends for me to assist in collecting molecular diagnostic data to check for the occurrence of diseases in certain desert tortoise populations, such as those at our Desert Tortoise Conservation Center (DTCC) in Las Vegas or those in the wild. This past visit, I was testing many different types of tissues for the presence of bacteria such as Mycoplasma agassizii, M. testudineum, and viruses such as tortoise herpesvirus-2. It’s always very interesting for me to go to the WDL, because I get to see the process of determining a tortoise’s health status on the molecular level from start to finish.

It all starts with the collection of a broad range of tissues including each major organ system, tissues with gross lesions, and nasal flushes during necropsy using sterile technique. These tissues are then snap-frozen in liquid nitrogen and placed into a -80 degrees Fahrenheit (-62 degrees Celsius) freezer where they eagerly wait for someone to extract their DNA and discover the secrets they hold about the health status of a particular tortoise. Next, it is decided what pathogens to test for based on pre-mortem clinical signs and/or gross and histologic findings during necropsy and based on previous or current health issues within the population.

To do this, DNA is extracted with the help of a kit that contains all the buffers and tubes necessary to free DNA from its bounds within the cell. Once the DNA is extracted and cleaned, the quality and quantity of DNA is evaluated, and the freshly made DNA can be used for testing. This testing is usually a Real-time Polymerase Chain Reaction (qPCR) assay or test. The assays are specific for the pathogens in question and will detect minute amounts of pathogen DNA within the extracted pool. With this test, we are able to screen for pathogens that are suspected of infecting and making sick the desert tortoises exhibiting signs of illness on site.

If it weren’t for the capabilities the San Diego Zoo provides, these tortoises would not get the top-notch, round-the-clock care they receive based on the quick turnaround of test results. These quick results can then be utilized to lessen the effects of what could be a large-scale outbreak occurring in a particular population, in this case the tortoises at the DTCC. It is very important that we stay on top of the health status of potentially releasable tortoises, because the last thing we want to do during a translocation is cause the exposure of a previously unknown disease to wild tortoises whose very population we are trying to augment.

Larisa Gokool is a research associate at the San Diego Zoo Desert Tortoise Conservation Center. Read her previous post, Desert Tortoise CSI.

2

Tortoises and Their Amazing Feats

A translocated desert tortoise carries the radio transmitter and GPS unit we use to monitor its movements.

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.

1

Rabbits, Rodents, and Tortoises

A new perimeter fence for the DTCC.

Hello again to all desert tortoise enthusiasts! It’s about that time of year for desert tortoises to begin their winter hibernation. For anyone who is new to the desert tortoise Gopherus aggaszzi, this is the time of the year when temperatures start to drop and food becomes scarce. With this seasonal change, desert tortoises begin to slow their metabolism and physical performance and search for a dark, comfortable burrow to “sleep in” through the winter until temperatures warm and food becomes more available.

Finding a secure, empty burrow in the Mojave Desert can be more difficult than just finding a hole in the ground. Desert tortoises search or create their own shelters: they may dig burrows, take another animal’s burrow, or find a small cave that protects them from the cool winters of the Mojave Desert. There are many other animals here that also are looking to hibernate or find shelter from the cold; they may cohabit a burrow with the desert tortoise through the winter season. Animals that have been known to share burrows with desert tortoises are black-tailed jackrabbits and desert cottontail rabbits as well as predators like kit foxes, coyotes, and even badgers.

Recently at the San Diego Zoo Desert Tortoise Conservation Center (DTCC), a new, reinforced fence was built to help control the movement of predacious animals onto the property. Prior to the new fence, coyotes, kit foxes, and even badgers would dig below the fence line to enter the property. This situation became a problem due to attacks on the desert tortoises and the destruction of the grounds at the DTCC. Once the new fence was built, there were no more issues with predacious animals entering, killing, or harming the tortoises.

Unfortunately, the DTCC now has a much larger problem with the local fauna. Since larger, predacious animals are not entering the property, nothing is controlling the population of smaller mammals such as rabbits and antelope ground squirrels. These animals do not directly harm the tortoises at the DTCC but harm them indirectly by scavenging the tortoises’ chow, grasses, and water we put out for the tortoises. It only shows that changing an animal’s ecosystem is not always the best answer to conserving that ecosystem.

Daniel Essary is a research associate at the San Diego Zoo’s Desert Tortoise Conservation Center. Read his previous post, Desert Tortoise: Hot, Hot, Hot.

4

Saving Tortoises, One Urolith at a Time

An x ray shows an adult desert tortoise with a large urolith on the left.

The tortoises have begun their fall slow-down and are preparing for their winter brumation (reptilian hibernation) here at the San Diego Zoo Desert Tortoise Conservation Center in Las Vegas. This means that the priorities in the medical center will shift a bit. We will have a few tortoises staying awake for the winter because they are either too sick or injured to brumate. However, we will also have a number of residents staying in the medical center waiting to have surgery at the state-of-the-art Harter Veterinary Medical Center, located at the San Diego Zoo Safari Park. All of these tortoises have dangerous uroliths that have developed in their bladder (uroliths are analogous to kidney and bladder stones in people).

A large stone removed from an adult tortoise carcass

Uroliths develop for various reasons, the most common being improper nutrition or prolonged dehydration. One of the adaptations that tortoises have that allows them to thrive in the arid desert environment is the ability to store large amounts of water in their bladder and to reabsorb it as the body needs it. As they reabsorb the water in their bladder, the solid particles in the bladder become more concentrated and can stick together. As time goes on more solids are deposited in the bladder and combine with those already present, forming a stone. Therefore, stones are more likely to form if a tortoise goes long periods of time without consuming fresh water to flush and replace the stored water.

Small stones that form can pass out of the bladder when the animal eliminates. However, once the stone becomes a certain size, it can be too big to pass and remains in the bladder where it can continue to get larger. If the stone is there long enough, it can adhere to the walls of the bladder, making it very difficult to surgically remove it without damaging the bladder. Eventually the stone can get large enough to take up most of the bladder space, thereby taking up very important water storage space. This compounds the problem by increasing dehydration in the tortoise. Eventually the stone can block the urethra, preventing the tortoise from eliminating at all and causing a build up of toxins in the tortoise. The long-term presence of uroliths can result in a prolonged, painful death.

A desert tortoise recovers from surgery to remove a stone.

We palpate every tortoise during its health assessment to see if we can feel a coelomic mass. Sand or gravel in the bowels or eggs can feel similar to uroliths during palpation, so we x-ray every tortoise in which we feel a mass to determine what the mass is. Once we have x-ray confirmation that it’s a urolith, we send the tortoise to the hospital, where veterinarian Nadine Lamberski has developed a less invasive technique to remove the stone. Traditionally, the most common stone removal technique used by veterinarians was to remove part of the plastron (the bottom part of the shell) to get to the stone. This procedure is very invasive and can take a very long time to heal since the bone of the plastron has to be removed. The veterinarians at the Safari Park use a technique in which they make an incision in the skin of the prefemoral area (just in front of the hindlimb) so they can access the stone and break it down and remove it without having to remove part of the shell. This surgery can take up to 6 hours to perform, but the recovery time for the tortoise is much quicker for this procedure. I am very excited to say that the veterinarians have performed a number of these surgeries successfully, and our tortoises have been able to return to us with a much better future in store for them.

We have a number of tortoises ready for surgery this winter. Once they recover, they will be able to be released to the wild Mojave Desert in the healthiest condition possible next year to live out their long lives in a natural environment.

Rachel Foster is a research associate at the San Diego Zoo Desert Tortoise Conservation Center. Read her previous post, Desert Tortoise Hibernation: Not for All.

2

Tortoise Tales: Tracking Desert Tortoises

Lindsey poses with a desert tortoise in the Mojave Desert.

We translocated a group of desert tortoises from the San Diego Zoo’s Desert Tortoise Conservation Center (DTCC) into the wild Mojave Desert and followed them to study their movements post-release (see Spring Desert Tortoise Translocation).  My days started at 5 a.m. at the release site out in the desert. There are six separate sites that our tortoises reside in, and it was my job to locate every one of these tortoises every week. While working on this project, I saw some interesting things in the desert!

Immediately after translocation, the tortoises began to move around looking for their new homes. A small group took an especially long journey to the corner of the site, all at least a kilometer (0.6 miles) away from each other and from any other study tortoise. One resident tortoise living in this area joined our study, so we were able compare her movements as a normal wild tortoise to those of the tortoises we translocated. I nicknamed her Mrs. Rogers, because she was the only resident tortoise in a whole neighborhood of translocated tortoise friends. This site from then on was known as Mrs. Rogers’ neighborhood. In the future, we hope a male tortoise will take on the role of Mr. Rogers to help increase the population!

Lindsey uses tracking equipment to help find translocated desert tortoises.

I ran into a bit of luck one day while tracking a resident tortoise in another area. When I finally located her, I saw that she was flipped on her back, unable to right herself.  Was this due to a scuffle with another tortoise or a run-in with a predator? Because of the unique anatomy of a tortoise, death can occur if a tortoise remains on its back for an extended period of time because it is vulnerable to dehydrating and overheating if unable to seek shelter during the hottest parts of the day. I immediately righted the tortoise, wondering if I was too late. Fortunately, she walked away, seemingly unharmed.  A month after that incident, that resident tortoise is still doing great!

Sometimes, tracking tortoises can be a tricky job. Change in elevation, tortoise movement, and other obstacles make it difficult to get a good signal on our equipment. Sometimes, though, the tortoises make it easy. As I drove down the desert road, I was listening for one tortoise when I saw another study tortoise walking across my path. At first I was pretty excited, because this was one less animal I had to search for, but then I noticed he was missing his GPS unit, which we attached to him before he was released. The GPS units are only programmed to emit a signal for a certain period of time, and at that moment I only had about five minutes to locate it before the signal stopped. I quickly entered the GPS frequency and began searching for the unit. I finally found the missing unit in the mouth of a nearby burrow only a moment after the beeping stopped. The unit was recharged and reprogrammed and put back on the tortoise shortly after.

One afternoon I was tracking a group of tortoises in a wash, and I found something none of us had yet come across. There were several broken eggs in the dirt surrounding the caliche cave where one of my tortoises was living. Unfortunately, a predator attacked this clutch before hatching, but under good environmental conditions a tortoise may produce two clutches per year, so maybe next time we will see some hatchlings!

This badger was found in a desert tortoise burrow.

It is not unusual to come across a tortoise digging a soil burrow while tracking our study animals. One morning I was approaching a burrow in a wash, and I saw dirt flying out of it. As I got closer I came face to face with an American badger staring at me from the entrance of the burrow. I was getting an extremely strong signal from the burrow, indicating the tortoise that I was looking for was inside!  Badgers are carnivorous and are known to prey on tortoises, so I was concerned for the well-being of our study tortoise. I sat down several meters away to fill out my data sheet, which took several minutes.  I got up to leave and walked over to the burrow to take one last look. Our tortoise was looking right back at me! I guess the badger and tortoise are just two friends sharing a burrow.

My summer as a telemetry technician was filled with ups and downs: hiking, pulling cactus spines out of my legs, amazing wildlife, and awkward tan lines. Now, at the end of the summer, I can say the tortoises are all doing well and have somewhat settled down into homes throughout the site. They are interesting little creatures, and I hope the work we did and the data we documented will help make future projects a success!

Lindsey Perry was a seasonal research assistant at the San Diego Zoo’s Desert Tortoise Conservation Center. Thank you, Lindsey!