The Fish and Wildlife Service has rejected a bid to extend endangered species protection to a rabbit-like creature that environmentalists say could be pushed to extinction by rising temperatures.

The warming of the American pika's mountain habitat in California's Sierra Nevada and in parts of nine other Western states has shrunk the tiny mammal's population and could eliminate part of its range, but federal biologists say new studies suggest the pika will adjust to warmer homes or migrate to cooler areas upslope.

"American pika can tolerate a wider range of temperatures and precipitation than previously thought," the biologists wrote in a finding scheduled for publication next week in the Federal Register. "We have determined that climate change is not a threat at the species- or the subspecies-level now or in the foreseeable future."

The thick coats that help pika survive winter can roast them if temperatures rise above 77 degrees Fahrenheit for as little as six hours.

Western temperatures could increase by up to 5.4 degrees Fahrenheit by midcentury and by 10 degrees Fahrenheit by 2100, according to the National Oceanic and Atmospheric Administration and the U.N. Intergovernmental Panel on Climate Change. The service declined to consider the effects of warming after 2050, saying there was too much variability in climate projections.

Shaye Wolf, a biologist for the nonprofit Center for Biological Diversity, which petitioned in 2007 for the pika's protection under the Endangered Species Act, said the service's decision underestimates perils facing the animal.

Said Greg Loarie, an attorney with Earthjustice: "To conclude the species is not even threatened by climate change is truly irresponsible."

Environmentalists are still weighing their response to the decision, said Loarie, who did not rule out a lawsuit.

The decision is a setback in environmentalists' campaign to link endangered species protection and climate policy.

The Center for Biological Diversity and other groups maintain that the Endangered Species Act compels the government to consider the effects of greenhouse gas emissions on protected species from proposed projects ranging from logging on public land to permitting of new power plants.

President George W. Bush's administration explicitly prohibited consideration of greenhouse gas emissions in federal project reviews when it listed the polar bear under the species law in 2008. And the Obama administration agreed with that approach last May, saying legislation is the appropriate vehicle for addressing climate change.

"Listing the pika would have forced the Obama administration to take a hard look at climate change, and a very important part of that is bringing the Endangered Species Act tool kit to the fight against global warming," Wolf said.

"That was a fight in the Bush administration, and the Obama administration isn't doing much better," she said.

Reprinted from Greenwire with permission from Environment & Energy Publishing, LLC., 202-628-6500