Despite documented threats posed to the American pika (Ochotona princeps) by global warming, the rapidly disappearing mammalian species will not be protected under the Endangered Species Act, the U.S. Fish and Wildlife Service (FWS) ruled last week.

Almost exactly one year ago, the FWS agreed to assess the health of the pika—a tiny cousin of the rabbit—in response to a lawsuit from the Center for Biological Diversity (CBD) and Earthjustice. At the time, the pika was the first non-Alaskan species to be considered for Endangered Species Act protection due to threats resulting from global warming.

"After review of all available scientific and commercial information, we find that listing the American not warranted at this time," read the FWS report of its 12-month review of the species. The report is due for publication February 8 in the Federal Register.

The American pika lives on cold mountain peaks in the U.S., where the 36 pika subspecies have adapted for a very specific environment and temperature range. According to the CBD, in Tucson, Ariz., the pika can overheat and die when exposed to temperatures as low as 25.5 degrees Celsius for just a few hours. Pika have disappeared from more than a third of their previously known habitats in Nevada and Oregon, and other populations have moved nearly 300 meters upslope from where they used to be found.

But the FWS disagrees with the assertion that the pika will not survive warmer temperatures, or that it will run out of suitable habitat if it keeps climbing upward for colder habitat. "Although the American pika is potentially vulnerable to the impacts of climate change in portions of its range, the best available scientific information indicates that pikas will be able to survive despite higher temperatures," a FWS press release stated. According to the FWS, the pika can tolerate temperatures up to 40 degrees C.

Going into more specifics, FWS field supervisor Larry Crist told the Los Angeles Times, "We believe that in some low elevations pikas are likely to decline, but we see no danger of extinction through 2050."

(The FWS also disagrees as to the number of pika subspecies, saying its review identified just five subspecies.)

Environmental groups, obviously, aren't happy with this decision. "We've already lost almost half of the pikas that once inhabited the Great Basin, and scientists tell us that pikas will be gone from 80 percent of their entire range in the United States by the end of century," Earthjustice attorney Greg Loarie said in a prepared statement. "To conclude that this species is not threatened by climate change is an impossible gamble that we can't afford."

A recent article in last month's issue of the journal BioScience conflicts with the FWS's science. "The high-energy mammals can overheat and die at temperatures as mild as 25 degrees Celsius if they can't regulate their body temperature by moving into the cooler microclimate under the talus," author Wendee Holtcamp wrote. "And since they already live near the tops of mountains, when a particular talus field's microclimate becomes inhospitable, they simply have nowhere to go."

Shaye Wolf, a CBD biologist, called the FWS's move "a political decision that ignores science and the law," in a prepared statement. "Scientific studies clearly show that the pika is disappearing from the American West due to climate change and needs the immediate protections of the Endangered Species Act to help prevent its extinction."

The FWS hasn't closed the doors on the pika—although that door isn't exactly wide open either. The Federal Register report says, "We ask the public to submit to us any new information that becomes available concerning the threats to the American pika, the five subspecies, or its habitat at any time."

Let's hope that "new information" comes quickly enough.

Image: American pika, via Wikimedia Commons