Threatened lawsuits, bad publicity and new policies have prompted the U.S. Fish and Wildlife Service to reconsider whether it should list as endangered a rare Rim Country snake that hunts fish in Tonto Creek and the Verde River.
The Fish and Wildlife Service will accept comments from experts and the general public on the status of the Mexican garter snake, which can dive to the bottom of ponds chasing fish, break off its tail and play dead with its head buried in its striped coils, while its tail goes wriggling off to decoy a predator.
The Fish and Wildlife Service had previously decided not to consider listing the snake although it survives in only a handful of streams in Arizona and is listed as endangered in Mexico. But the agency said since it didn't have any good information about the snake's status in Mexico, it couldn't tell if it was endangered.
But the agency recently changed its mind and agreed to consider a listing.
Environmentalists applauded the decision. "We're relieved the Mexican garter snake is once again on track to receive the protection it desperately needs to survive," said Center for Biological Diversity Science Director Noah Greenwald. "We're relieved the Mexican garter snake is once again on track to receive the protection it desperately needs to survive."
Jeff Humphrey, a spokesman for the Fish and Wildlife Service, said the agency decided to reconsider after lawsuits prompted a shift in policy.
Previously, the Fish and Wildlife Service had generally refused to list faltering regional subpopulations if the species was doing well elsewhere. Several court cases have prompted the agency to consider listing a species that has been wiped out in a "significant portion" of the species historical range.
"We had just never gotten our arms around the phrase ‘significant portion of the range' of an endangered species," said Humphrey.
The agency's Sept. 26, 2006 report on the water-loving garter snake concluded the frog, insect and fish-hunting snakes have vanished from thousands of miles of streams. Moreover, the snake has suffered from competition and predation by introduced species like bullfrogs and crayfish.
The long report documents the shrinkage of the snake's range from about half of Arizona to a handful of streams and ponds, including Tonto Creek and portions of the Verde. River. But after detailing the snake's rapid decline, the report concludes with a straight face that the lack of information from Mexico makes it impossible to consider the snake endangered.
Greenwald says agency memos show that administrators overruled the findings of field biologists.
Humphrey said the reconsideration mostly stemmed from evolving federal policies about how to interpret certain portions of the Endangered Species Act.
The same shift in policy could affect the decision as to whether to list desert bald eagles as endangered. As it happens, the riparian habitat crucial to the desert bald eagles will also mostly qualify as critical habitat for the Mexican garter snake.
Wildlife advocates say an endangered species listing gives them a legal tool to protect the habitat on which the species depends. But that's also why many development interests fight listings for fear the federal government will restrict other uses of crucial habitat. In the case of the Mexican garter snake, the critical habitat includes many of the state's most endangered, but heavily contested, riparian areas.
Behind those battle lines of science and politics wriggles a remarkable snake once found in virtually every Arizona stream and river.
The snakes can grow to five feet long, but first must survive for several years as a bite-size wiggle in ponds, streams and stock tanks crowded with bass, crayfish, bullfrogs and other introduced predators.
Intensive efforts to find the snakes throughout their once wide historical range have resulted in dramatic, documented declines in recent years.
Biologists have concluded that cattle grazing has a dramatic impact on the snakes by altering riparian areas. Cattle tend to hang around streams in desert and semi-desert areas unless kept away with fences. Streams along which cattle graze have about one-sixth as much vegetation, warmer shallower water and more silt -- all factors that strongly affect riparian species like the garter snakes, concluded the report.
Similar problems face the snake in Mexico, where key streams have "experienced a staggering amount of degradation" in the 20th Century, with only an estimated 15 percent of the streams still able to support "sensitive species" like the Mexican garter snake.
Humphrey said that the federal government will gather information on the status of the snake for the next year including any sightings by the general public.
He recommended that anyone in Rim Country who finds a snake swimming in the water try to get a picture of the head before reporting the finding, since the Mexican gartner snake closely resembles several other nonendangered garter snakes.
Anyone who does have information to report can do so through a public comment Web site at www.regulations.gov.