Frogs that are increasingly rare in the Sierra Nevada will not be listed for protection under the Endangered Species Act, despite a federal study that indicates its population is dwindling fast.
The U.S. Fish and Wildlife Service said the amphibian warrants protection, but will not be put on the list of threatened and endangered species because other species take a higher priority than the mountain yellow-legged frog.
The Center for Biological Diversity and the Pacific Rivers Council filed a petition with USFWS in 2000 that led to a 12-month study of the species. The study determined the population has been decreased by 50 to 80 percent of its historical numbers throughout the Sierra.
The agency attributes the decline to the stocking of nonnative fish, disease, air pollution and the effects of ill-managed livestock.
Earthjustice, a nonprofit law firm, announced it intends to sue USFWS to fight its decision not to list the frog. Earthjustice said it will file the suit on behalf of the Center for Biological Diversity and Pacific Rivers Council.
"This maneuver is indicative of the Bush administration's disregard for imperiled wildlife and contempt for the Endangered Species Act," said Jeff Miller, spokesman for the center. "The administration hasn't tried to cover up the fact that it is hostile to the act."
USFWS made a similar ruling on the Yosemite toad in December. The frog and toad could become extinct while waiting to be listed. Miller said 25 amphibian species are on the "warranted-but-precluded list," and on average it takes about 17 years to reach the top.
The mountain yellow-legged frog is considered by the state of California to be a species of special concern, but is not listed as threatened or endangered and therefore not protected under the state's Endangered Species Act.
Mark Jennings, a research associate at the California Academy of Sciences, collected data in the late 1980s and early '90s that state officials used to determine the status of frogs, fish and amphibians. He said yellow-legged frogs are disappearing even from protected habitats.
"Beside tree frogs ... frogs are in decline around the state," he said. "They are disappearing over wide areas, and we just don't know why."
Populations of the mountain yellow-legged frog in Southern California, distinct from members of the species that live in the Sierra, were listed as endangered by USFWS last year.
"It's clear this amphibian continues to disappear, despite it being listed," Jennings said.
The mountain yellow-legged frog is native to California and typically found in the Sierra and its foothills from 4,500 to 12,000 feet. They favor glacial lakes and can be found west of Lake Tahoe in areas, such as on Tahoe National Forest.
The frog is 2 to 3 inches long, with a belly and legs that are often orange or yellow and backs that are yellowish or reddish brown with black or brown spots.