Thursday, June 11, 2009

Pika: Mountain Critter at Risk


An endearing little furball, the American pika is well-known to hikers who hear these hamster-sized mammals whistling from rockpiles and talus slopes.
Their range includes Canada and the Mountain West, occurring at cool northern latitudes and high altitudes. Until recently, they were not considered especially threatened.
But a 2003 study in the Journal of Mammalogy reported that 7 out of 25 historic Great Basin populations had disappeared, and 2 more Great Basin population extinctions were discovered after publication.
Global Warming Threats
Some may like it hot but not the pika. Even brief exposures (as little as a few hours) at temperatures above 78 degrees F can be fatal. Plus they rely on snowpack for insulation in the winter.
In the southern portions of its range, some populations already occupy the highest altitudes, with no place to move upward to escape the heat.
The US Fish and Wildlife Service is currently considering the pika for listing under the Endangered Species Act, which would make it the first mammal in the lower 48 to be listed due to global warming.
Wider Implications
Pikas have frequently been described as the ‘canaries in the coal mine’ of alpine and montane ecosystems in the western U.S. – their disappearance is an alarming signal of sweeping climate disruptions.
And, like prairie dogs, pikas are pruners and help maintain the diversity and abundance of alpine meadow plant species.
Other Western Species at Risk
The American West is in global warming's crosshairs. Warmer winters will lead to less snowpack in the mountains, which will exacerbate already worsening droughts in the region. There has already been a four-fold increase in the number of major wildfires in western forests.
According to the National Wildlife Federation, western sagebrush habitats could decline by 59 percent before the end of this century, devastating sage grouse, mule deer, pronghorn and other species.
Higher stream temperatures and less water flow could threaten trout and other western cold-water fish.
Sources
http://www.bioone.org/doi/abs/10.3398/1527-0904%282008%2968%5B8%3AAPOPIN%5D2.0.CO%3B2?journalCode=wnan
http://faculty.washington.edu/grayson/grayson-pikas.pdf
http://www.fws.gov/mountain-prairie/pressrel/09-34.html

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