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Rapidly Declining Desert Icon Still in Legal Limbo
Arizona-Feb. 2. WildEarth Guardians and Western Watersheds Project today filed suit against the U.S. Fish and Wildlife Service (Service) over the agency’s failure to decide whether the Sonoran desert tortoise deserves protection under the Endangered Species Act. The conservation groups submitted a scientific petition in 2008 requesting federal protection for the tortoise. Although the Service issued a positive preliminary decision on that petition in August 2009, its final decision on whether to protect (list) this tortoise under the Act was due over three months ago. The petition demonstrated that monitored populations of the tortoise have declined by more than 51% since the government originally refused it protection two decades ago.
“We are seeking prompt federal protection for the tortoise because it simply cannot afford another minute of delay. This iconic desert dweller has already suffered disastrous declines due to the government turning a blind eye to its imperilment,” stated Dr. Nicole Rosmarino of WildEarth Guardians.
The Sonoran desert tortoise occurs in southwest Arizona and northern Mexico. In its August finding, 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 must also address a small desert tortoise population named in the groups’ petition that lives in the Black Mountains in northern Arizona. Federal protections for other tortoises, such as the Mohave Desert Tortoise, have led to the protection of millions of acres from livestock grazing, off-road vehicle use, and other harmful activities.
“The science shows that Arizona’s Sonoran and Black Mountains desert tortoises are in serious trouble. We expect that the Service’s status review will confirm that listing under the Endangered Species Act is necessary to protect these tortoises from becoming extinct in a significant portion of their range,” stated Dr. Michael Connor of Western Watersheds Project and a twenty year advocate for desert tortoise protection.
In its August decision, 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 need to qualify under a minimum of just one of these factors. The list of threats the tortoise faces is long, including: habitat loss from livestock grazing, urbanization, border activities, off-road vehicles, roads, and mining; 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.
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.
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.
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 its August 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 that 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 in Arizona.