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American Pikas and Global Warming
Millar, C.I. and Westfall, R.D. 2010. Distribution and climatic relationships of the American Pika (Ochotona princeps) in the Sierra Nevada and Western Great Basin, U.S.A.; periglacial landforms as refugia in warming climates. Arctic, Antarctic, and Alpine Research 42: 76-88.

American pikas are small generalist herbivores that are relatives of rabbits and hares. They tend to inhabit patchily-distributed rocky slopes of western North American mountains and are good at tolerating cold. However, they are widely believed to have a physiological sensitivity to warming, which when "coupled with the geometry of decreasing area at increasing elevation on mountain peaks," in the words of the authors, "has raised concern for the future persistence of pikas in the face of climate change," so much so, in fact, that "the species has been petitioned under California [USA] state and federal laws for endangered species listing."

What was done
Millar and Westfall developed a rapid assessment method for determining pika occurrence and used it "to assess geomorphic affinities of pika habitat, analyze climatic relationships of sites, and evaluate refugium environments for pikas under warming climates," while working over the course of two field seasons in the Sierra Nevada Mountains of California, the southwestern Great Basin of California and Nevada, and the central Great Basin of Nevada, as well as a small area in the central Oregon Cascades.

What was learned
The two U.S. Forest Service researchers report that "whereas concern exists for diminishing range of pikas relative to early surveys, the distribution and extent in our study, pertinent to four subspecies and the Pacific southwest lineage of pikas, resemble the diversity range conditions described in early 20th-century pika records (e.g., Grinnell and Storer, 1924)." In fact, they say that the lowest site at which they detected the current presence of pikas at an elevation of 1827 meters "is below the historic lowest elevation of 2350 m recorded for the subspecies by Grinnell and Storer (1924) in Yosemite National Park; below the low elevation range limit for the White Mountains populations given by Howell (1924) at 2440 m; and below the lowest elevation described for the southern Sierra Nevada populations of 2134 m (Sumner and Dixon, 1953)." In addition, they report that "a similar situation occurred for another lagomorph of concern, pygmy rabbit (Brachylagus idahoensis), where a rapid assessment method revealed much wider distribution than had been implied from historic population databases or resurvey efforts (Himes and Drohan, 2007)."

What it means
Millar and Westfall say their results suggest that "pika populations in the Sierra Nevada and southwestern Great Basin are thriving, persist in a wide range of thermal environments, and show little evidence of extirpation or decline," over a period of time, we might add, when the world's climate alarmists claim the planet warmed at a rate and to a level of warmth that was unprecedented over the past one to two millennia, which suggests to us that current concerns about the future of American pikas in a warming world may be wildly misplaced. Moreover, the documentation of a similar phenomenon operating among pygmy rabbits suggests that still other animals may also be better able to cope with various aspects of climate change than we have been led to believe possible.

Grinnell, J. and Storer, T.I. 1924. Animal Life in the Yosemite. University of California Press, Berkeley, California, USA.

Himes, J.G. and Drohan, P.J. 2007. Distribution and habitat selection of the pygmy rabbit, Brachylagus idahoensis, in Nevada (USA). Journal of Arid Environments 68: 371-382.

Howell, A.H. 1924. Revision of the American Pikas. North American Fauna No. 47. USDA Bureau of Biological Survey, Washington, DC, USA.

Sumner, L. and Dixon, J.S. 1953. Birds and Mammals of the Sierra Nevada. University of California Press, Berkeley, California, USA.

Reviewed 16 June 2010