Desert Tortoise Care at the Ivanpah Solar Project
On March 4th, the Los Angeles Times published an article by Julie Cart titled, “Saving desert tortoises is a costly hurdle for solar projects.” The story does a good job of highlighting the historic challenges faced by the desert tortoise over the millennia. However, there were several inaccuracies that need correction and instances where additional information would have provided important context for the reader, such as the extensive desert tortoise care program in place at the Ivanpah project. This is important to understand because desert tortoise mortality rates in the natural environment are as high as 98 percent. Tortoise care programs for hatchling and juvenile tortoise provide a critical path for improving survival rates by providing support and protection from ravens, kit foxes, and coyotes and other factors such as drought and disease during approximately the first five years of life.
The Ivanpah project owners – NRG, Google and BrightSource Energy – are going to great lengths to ensure minimal impact to the desert tortoise population at and near our project site. In fact, one of our project/company goals is to help the repopulation of the desert tortoise. We currently care for 170 juvenile desert tortoise (including 53 newborn hatchlings). These juveniles are cared for and will be reintroduced into the wild once they are large enough to resist predation. Our desert tortoise care program is actively supporting efforts to repopulate the desert tortoise in the Ivanpah Valley. We are working extensively with government agencies California Energy Commission, Bureau of Land Management, California Department of Fish and Game, U.S. Fish and Wildlife Service, Mojave National Preserve and the environmental community to develop a thoughtful and responsible tortoise mitigation strategy.
On behalf of the Ivanpah SEGS project, we are proud of the significant efforts we have put forth to care for and protect the desert tortoise as we work to bring clean, solar power to California homes.
The information below corrects inaccuracies found in the article and describes the many ways we’re working with biologists to protect this critical species.
Corrections to the LA Times Story
1) The LA Times incorrectly refers to the desert tortoise as an endangered species. The desert tortoise is federally-listed as a threatened species – not an endangered species. Endangered is a more serious designation within the Endangered Species Act, meaning that the species is currently on the brink of extinction. Threatened species do not currently face the same risk, although they are protected to help prevent their becoming endangered.
2) Contrary to the LA Times story, the developers of the Ivanpah SEGS site were not aware of the heavy tortoise populations prior to selecting the project location. The BLM has designated the land on which Ivanpah SEGS is located as the “least important” category (Category 3) of habitat for the desert tortoise. This land is not within any defined critical habitat or under any special protection. In fact, the nearby area has significant human disturbances, including an adjacent 36-hole golf course, numerous transmission lines and casinos and outlet shopping stores approximately five miles from the site. The area is also a popular location for off-road vehicle enthusiasts and land-sailors.
Initial desert tortoise surveys conducted by biologists found 17 desert tortoise on site, a very low density of tortoise relative to the average for this area, and particularly relative to areas designated for special protection, which have as much as 10 times the density of desert tortoise. We have since come to understand that these numbers were not representative, as the surveys were undertaken during relatively dry years when tortoise remain underground. The numbers detected during the construction phase were far higher. Still, the number of desert tortoise found on site is only slightly above the average range for the tortoise in the nearly five million acres of habitat within the Northeastern Mojave Recovery Unit, one of multi-million acre recovery units that have been designated.
3) The LA Times wrongly states that “the tortoise brought construction to a standstill for three months.” The Bureau of Land Management issued a stop-work order that affected only the portion of the site that had not yet been screened for tortoise. Construction continued as planned elsewhere and the overall construction schedule was not affected. The project remains on-schedule and we expect the plants to begin delivering power to our customers in 2013. For more information, please see the blog post here.
Important Information about the Ivanpah SEGS Tortoise Care Program
- Financial Investment: The project owners have to date spent approximately 22 million dollars caring for the desert tortoises found on or near the site. This figure includes biologist salaries, materials for constructing the tortoise pens, establishing our head-start program, installing tortoise fencing around the project site and along I-15 and other general tortoise biology work. In addition, we will spend up to $34 million to meet the project’s federal and state mitigation obligations, which include tortoise habitat restoration, the installation of an additional 50 miles of protective tortoise fencing and the minimum purchase of 7,164 acres of conservation habitat. This is the equivalent of 2 acres for every 1 acre of development.
- Biologists: The desert tortoise biologists at Ivanpah operate under strict protocols set forth by the Bureau of Land Management. At any given time, there are dozens of trained biologists on site to make sure that every tortoise on site is accounted for and given the highest levels of care. At certain periods of the construction process, there have been up to 100 biologists actively working on the project. The biologists walk 15-30 feet apart closely examining the landscape, looking in and excavating every animal hole, under every rock and every bush to make sure that all tortoise onsite were accounted for. Additionally, they accompany construction workers and equipment in the field and are fully authorized to halt construction if there are any concerns.
- Nurseries: For tortoise found on site, biologists are following a careful procedure to give them new homes within a mile of the project site. The tortoise are first moved to a nursery where biologists recreate their burrows, using sand and scat from their original homes and ensuring even the orientation of the new burrows matches their original homes. The tortoises are kept there until the biologists can conduct the appropriate medical tests and ensure that the animals are free of a respiratory disease common in the species. Then they will be placed in new areas within a one mile perimeter outside of the power plant construction zone.
- Hatchery “Head Start” Program: In an effort to help facilitate the rebuilding of the desert tortoise population in the Ivanpah Valley area, we have partnered with the Mojave National Preserve to create a hatchery “head-start” program on site. Head-start programs have been found to provide a critical avenue for enhancing repopulation of the desert tortoise by providing support and protection for hatchling and juvenile tortoise during approximately the first five years of life, or until they are large enough to resist predation from ravens, kit foxes, and coyotes and other factors such as drought and disease. Hatchling and juvenile desert tortoise mortality rates in the natural environment are as high as 98 percent in some estimates. All juvenile desert tortoise found on the Ivanpah site and tortoise born in captivity will be cared for in the head-start program before being released into their natural environment. To date, the program has successfully cared for 117 juvenile tortoises and birthed 53 total hatchlings. Many more tortoises will be returned to the wild than would have survived in the wild if Ivanpah had not been built. The Ivanpah SEGS head-start facility is a highly secure, specialized juvenile tortoise pens to care for and protect the hatchlings. The pens will be carefully protected from predators – which include ravens, raptors, ground squirrels, foxes and coyotes – by special mesh security fencing. The fencing will be buried about a foot below ground to prevent predators from burrowing into the pens. Juvenile tortoises also require special habitat considerations because they may not be able to dig through rocky terrain. With just a few head-start programs in existence, the Ivanpah program will provide desert tortoise biologists with important information about head-starting and its effectiveness in repopulating the desert tortoise.
- Translocation: The desert tortoise currently being cared for in the tortoise nurseries and hatchery will ultimately be moved to adjacent land. Biologists follow stringent tortoise translocation protocols outlined by the Bureau of Land Management, US Fish and Wildlife Service and the California Department of Fish and Game. The majority of the tortoise will remain within their original “home range” (unlike tortoises translocated long distances to unfamiliar habitat) and will have comparable plant diversity and richness as the Ivanpah SEGS site. Keeping the tortoise close to their original homes greatly increases the rate of success for translocation. The tortoises will be monitored for a number of years following the translocation to ensure the safety of the tortoise.
- Long Term Monitoring: Biologists will be tracking the tortoises that are translocated from the project site as well as the tortoises outside the project site within the “receiving” area for five years. The biologists will use tracking information from nearly 400 tortoise (translocated and recipient populations) to ensure the safe integration of the two populations and gather additional insights on successful relocation procedures. Biologists will also study toxicity levels for one year and noise and vibration along the interstate for three years. This information will provide a wealth of data for future scientific studies of the desert tortoise species.
- Ivanpah SEGS Project Site’s Suitability as Desert Tortoise Habitat: In an effort to rehabilitate the desert tortoise population in the Mojave Desert, habitat is divided into six large areas, called “recovery units,” spanning tens of millions of acres across Arizona, California, Nevada and Utah. Within each recovery unit, the Bureau of Land Management categorizes the quality of the tortoise habitat, ranging from Category 1 (most important) to Category 3 (least important). In total, over 6.4 million acres have been identified as critical habitat for the tortoise across the six recovery units, including 4.75 million acres in California. In California specifically, the Mojave Desert spans over 20 million acres, covering about one-fifth of the state. The Ivanpah SEGS is located within the Northeastern Mojave recovery unit, which covers approximately nine million acres. The project’s land comprises approximately four-hundredths of one percent (0.04%) of the single recovery unit’s total acreage. In the broader Ivanpah Valley, over 630,000 acres have been designated as Critical Habitat for desert tortoise. The Ivanpah SEGS project is not located within any defined Critical Habitat, and has been designated by the BLM as the “least important” category (Category 3) of habitat for the desert tortoise. By comparison, the Ivanpah Desert Wildlife Management Area (DWMA) approximately five miles south of the Ivanpah SEGS has Category 1 habitat.