Carbon Dioxide and Earth's Future Pursuing the ... - Magazooms

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pikas 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 two scientists, “has raised concern for the future persistence of pikas in the face of
climate change.” Therefore, they write that the species “has been petitioned under California
[USA] state and federal laws for endangered species listing.” And in a study designed to
investigate the validity of the basis for that classification, 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.
In reporting their findings, the two U.S. Forest Service researchers state 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 say 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).”
Millar and Westfall thus conclude 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,” 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.
In providing some background for their study of montane rainforest lizards, Bell et al. (2010)
write that tropical species have long been considered to be “especially sensitive to climatic
fluctuations because their narrow thermal tolerances and elevational ranges can restrict their
ability to persist in, or disperse across, alternate habitats,” a concept that NASA’s James Hansen
expressed much more bluntly by declaring on 21 November 2006 -- when accepting the World
Wildlife Fund’s Duke of Edinburgh Conservation Medal at St. James Palace in London -- that
“species living on the biologically diverse slopes leading to mountains will be pushed off the
planet” as the planet warms, opining -- as we have already noted he also did before the U.S.
House of Representatives -- that there will simply be no place else for them to go.
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