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Groups Applaud Finding for Rapidly Declining Desert Icon
PHOENIX - The U.S. Fish and Wildlife Service (Service) gave the green light today on a petition submitted by WildEarth Guardians and Western Watersheds Project requesting protection (listing) for the Sonoran desert tortoise under the Endangered Species Act. The finding means that the Service will now conduct a full review to determine if the tortoise warrants being placed on the list of threatened and endangered species.
The Sonoran desert tortoise occurs in southwest Arizona and northern Mexico. The Service found that Sonoran desert tortoises qualify as a distinct population, different from other tortoises found in the Mojave Desert west of the Colorado River that were federally listed in 1990. The Service will also address a small desert tortoise population named in the groups’ petition that lives in the Black Mountains in northern Arizona in the status review.
“We are delighted with the Service’s initial response. Their findings are a strong indication that they are committed to using the best science available as they review the status of the Sonoran and Black Mountains desert tortoise populations. These populations have languished and declined since they were excluded from the 1990 listing. We expect that the Service’s detailed scientific review will show that listing is required to conserve these icons of the desert southwest,” stated Dr. Michael Connor of Western Watersheds Project and a twenty year advocate for desert tortoise protection.
The Service determined that the Sonoran desert tortoises may be threatened by all five factors the agency uses in deciding whether a species qualifies for Endangered Species Act protection: 1) habitat loss and destruction; 2) overutilization; 3) disease or predation; 4) inadequate legal protections; and 5) other factors. Under the Act, the tortoises needed to qualify under a minimum of just one of these factors. The full list of threats noted in today’s finding is long, including: habitat loss from livestock grazing, urbanization, border activities, off-road vehicles, roads, and mining; harm to individual tortoises from shooting, collection for pets or food, handling, and harassment; diseases such as upper respiratory tract disease, shell disease, and other pathogens; increased predation by ravens, coyotes, and feral dogs due to urban encroachment; inadequate legal protections, including on federal and state public lands; altered fire patterns due to exotic weeds; crushing and killing of tortoises by off-road vehicle users; and prolonged drought, exacerbated by the climate crisis.
“We applaud the Service for recognizing the broad suite of assaults facing the Sonoran desert tortoise. We will press the Service to take the next step and propose this rapidly declining desert dweller for Endangered Species Act protection,” stated Dr. Nicole Rosmarino of WildEarth Guardians.
The petition shows that monitored Sonoran desert tortoise populations have declined by 51 percent since 1987, or about 3.5 percent annually. This was based on an analysis of population trends in monitored areas throughout the animal’s range in Arizona conducted by independent scientists that was commissioned by WildEarth Guardians.
Because the initial finding on the petition is positive, the Service must now undertake a review of the status of the species and make a decision based on that review. If the tortoises are listed under the Endangered Species Act, they would be protected from “take” (including killing and harassment) of individual tortoises, and the agency would have to develop a recovery plan to map out the steps that must be taken to reverse the population declines. The Service must also identify habitat critical to the conservation and recovery of the species. With today’s finding, the Service announced the beginning of a 60-day public comment period during which additional information can be submitted by agencies and the public. The comment period ends on October 27.
Livestock grazing is a significant threat to the Sonoran desert tortoise. More than half of the tortoise’s estimated range in Arizona is on federal public land (8,406,692 acres) and more than half of that public land is permitted for livestock grazing (on more than 200 grazing allotments). Grazing is even permitted on important desert tortoise habitat in designated wilderness and in the Ironwood Forest and Sonoran Desert national monuments-areas purportedly established for conservation purposes.
The Sonoran desert tortoise has a number of characteristics that make it vulnerable to extinction. Tortoises do not reach sexual maturity until they are approximately 10-20 years old, and females produce only produce one clutch of eggs per year. Tortoise hatchlings have very soft shells, making them susceptible to predators and harsh weather. Tortoises depend on sufficient forage in a region that is heavily grazed by livestock and that is experiencing prolonged drought and effects of climate change. In today’s finding, the Service recognized the tortoises’ fragile existence, noting that the simple act of a human picking up a tortoise could cause the tortoise to urinate, which could jeopardize its life due to the resulting loss of water. Sonoran desert tortoises share their habitat with many other imperiled species, such as the lesser long-nosed bat and the cactus ferruginous pygmy owl, which would also enjoy benefits if this tortoise was listed under federal law.
WildEarth Guardians and Western Watersheds Project are conservation organizations with offices throughout the western United States, including Arizona.
View the Service's finding: http://edocket.access.gpo.gov/2009/pdf/E9-20835.pdf.