First tortoise translocation at Ivanpah
On Wednesday, we reached an important milestone at the Ivanpah SEGS: the first translocation of a desert tortoise found on the project site. This healthy female tortoise was relocated from her temporary home in the tortoise pens to adjacent habitat about 1,300 feet from the project site by trained desert tortoise biologists with oversight from Dr. Larry LaPre, a Bureau of Land Management biologist.
Desert tortoise emerges from her new burrow.
Prior to the move, these biologists had devoted hundreds of hours of monitoring and research in preparation for the tortoise’s eventual move back into the wild. This particular tortoise was found on the edge of Ivanpah’s Unit 3 in early spring prior to construction. Trained and authorized biologists attached a small transmitter to her shell that was used to help monitor her whereabouts and habits. Thanks to the biologist’s familiarity with her original routines, they were able to identify ideal habitat near her original home that contained an unoccupied burrow of comparable size, similar vegetation and familiar terrain.
In late spring, it was determined that the tortoise was carrying eggs, or “gravid.” The biologists moved her into a carefully designed nursery pen that protects against predators. About 90 days after laying two eggs, her hatchlings emerged and are now being monitored daily and will be relocated to the head-start pens in the coming weeks. (Read more about our head-start facility here.)
After confirming the tortoise had passed all medical tests, the Solar Partners biology team convened with the Bureau of Land Management and the US Fish and Wildlife Services. All parties agreed that she would be a strong candidate for returning her to the wild once the conditions were safe.
Wednesday morning, the biologists watched the thermometer closely, waiting for the day to reach to 65 degree Fahrenheit, the minimum temperature needed for relocation. Once the day warmed, the biologists gave the tortoise a brief inspection, weighed her, and placed her in a large plastic tub. After a 4.5-mile drive around the perimeter of the project to the relocation site, the biologists walked by foot the final 400 meters outside of the ISEGS fence line. Known as an “over-the-fence” translocation, the tortoise will remain well within its home range in a habitat with familiar soil composition, food sources, weather and terrain. The biologists located the preselected abandoned burrow and placed her at the mouth of the entrance. She immediately walked into the burrow until she could hardly be seen, stayed for a few minutes then walked out to find some nearby grass to eat.
Biologists wait for the temperatures to rise above 65 degrees Fahrenheit before relocating the desert tortoise.
Biologists carefully place the desert tortoise at the mouth of her new off-site burrow.
A biologist will stay with her for the next few days to ensure that she safely assimilates into her new surroundings. After a period of time, the monitoring will be reduced to once a week for up to 10 years. In the spring, many of the remaining tortoises at ISEGS will also be translocated to safe areas outside the project site. Our dedicated team of biologists is very hopeful and confident that this tortoise and the ones that follow will have a safe transition back into their natural habitat.
All of the desert tortoises found on the Ivanpah SEGS site are being carefully looked after by trained and authorized desert tortoise biologists. These biologists follow a very rigorous set of handling and care guidelines established by the Bureau of Land Management and the US Department of Fish and Wildlife Services to ensure the safety of the tortoise. For example, for each translocation, there are a very specific set of best practices followed to ensure a successful translocation:
- Each and every tortoise has its own individual “disposition” plan, which tracks the tortoise’s health, activity, habits. These factors are taken into consideration before they are introduced into a new area.
- Each tortoise undergoes a comprehensive medical assessment to verify that the animal is healthy and does not carry a potentially-fatal respiratory disease that is prevalent and contagious among the desert tortoise population.
- The receiving area where the tortoise will be relocated is surveyed numerous times in advance to determine if the “recipient population,” or existing tortoise residents are healthy and can safely accommodate additional tortoises.
- The animal can only be translocated during very specific periods in the spring and the fall.
- The animal can only be translocated when the temperatures are between 65 and 95 degrees F.
Biologists regularly track the habits and medical history of each tortoise in the nursery pens.
The desert tortoise peeks out from within the manmade burrow built for her by the biologists in the nursery pen.
Biologists gently lift the desert tortoise out of the nursery pen and into a plastic tub for relocation.