The federal government has agreed to consider whether the Sonoran desert tortoise, a Southwest icon whose population has declined by half in the past 20 years, warrants protection under the Endangered Species Act.
Two environmental groups petitioned the U.S. Fish and Wildlife Service to list the tortoise, found in southwest Arizona and northern Mexico, as a distinct population. The agency said Friday it would review the status of the tortoise and any threats to its habitat.
“We expect that the service’s detailed scientific review will show that listing is required to conserve these icons of the desert Southwest,” said Michael Connor of the Western Watersheds Project, which along with WildEarth Guardians filed the petition.
The tortoise is among 13 species and plants that environmentalists sought protection for with a series of petitions filed last fall as part of their “Western Ark” project.
Lawsuits followed in many of the cases for the species, whose ranges span more than a dozen states and stretch into Mexico and Canada. The latest was filed in Texas this week over six freshwater mussels found in the U.S. southeast.
Nicole Rosmarino of WildEarth Guardians said the group has received a number of positive findings as a result of the petitions and subsequent lawsuits. Those include federal wildlife officials’ decision to study the Jemez Mountain salamander, an elusive white-sided jackrabbit and the tortoise.
“With today’s finding, the tortoise has drawn even with the hare in the race to avoid extinction,” she said.
Since taking office, President Barack Obama has distanced himself from several Bush administration policies on the environment and vowed to help restore science at the Interior Department on issues including endangered species.
“We appreciate that, and we think that the Fish and Wildlife Service is doing a very good job of looking at the science, in really examining a whole suite of assaults that are facing this dwindling tortoise,” Rosmarino said.
Environmentalists estimate the tortoise’s population has fallen by 3.5 percent each year — a total of 51 percent — since 1987, but their exact number is unknown. The estimate is based on a sampling of tortoises in Arizona.
Wildlife officials said the environmentalists’ petition presented substantial information that might warrant listing the species as threatened or endangered. Threats include urban sprawl, off-road vehicle use and livestock grazing. The tortoises’ range includes 8.4 million acres of federal public land in Arizona. Livestock grazing is permitted on more than half that land.
The tortoise also is a popular pet, although Arizona Fish and Wildlife prohibits taking them from the desert or returning them because of concerns over the spread of disease or how it could affect genetics. Jeff Humphrey, a spokesman for the Arizona Fish and Wildlife Service, noted that during the 1950s and 60s, some gasoline stations gave away a desert tortoise with every fill-up. He said tens of thousands of desert tortoises call someone’s backyard home.
The Sonoran population lives mostly on rocky hillsides and take cover for much of the year. They are different from their flatland Mojave cousins found west of the Colorado River, which have been federally protected since 1989, Humphrey said.
Environmentalists, believing some of the Mojave population crossed the river at some point, petitioned the federal government to protect those found in the Black Mountains of northern Arizona as well.
A decision on the listing will follow a 12-month review. Since half of the range of the Sonoran tortoise is in Mexico, where the desert tortoise is listed as threatened, Humphrey said “we’re especially keen” to receiving information on their status there.