Lucas Moyer-Horner wrote: > Anita, Below are two excellent case studies that are near > and dear to my heart. As far as i know, this is the first > evidence of a small-medium sized mammal being extirpated > by rising temperatures.
> Beever, E.A., Brussard, P.F. and Berger, J. 2003. Patterns of > apparent extirpation among isolated populations of pikas > (Ochotona princeps) in the Great Basin. Journal of Mammalogy > 84(1):37-54 > Grayson, D.K. 2005. A brief history of Great Basin Pikas. > Journal of biogeography 32:2103-2111. Lucas, according to this article: http://www.hcn.org/servlets/hcn.Article?article_id=15849 "In the early 1990s, E.A Beever revisited 25 Great Basin pika populations recorded by Eugene Raymond Hall and others about half a century earlier and found six of the 25 populations had completely disappeared." The 25 pika populations that were monitored were located primarily within Nevada: http://i85.photobucket.com/albums/k75/4af/pikaa.jpg Now lets look at how much temperatures rose in Nevada between 1920 and 1993 using National Climate Center Data http://www.ncdc.noaa.gov/oa/climate/research/cag3/cag3.html Here is the winter (Dec-Feb) temperature graph for Nevada the period 1920-1993: http://i85.photobucket.com/albums/k75/4af/pikab.jpg A very slight warming trend is apparent Here is the summer (June-August) temperature graph for Nevada for the period 1920-1993: http://i85.photobucket.com/albums/k75/4af/pikad.jpg A slight cooling trend is apparent. Here is the overall annual temperature graph for Nevada for the period 1920-1993: http://i85.photobucket.com/albums/k75/4af/pikac.jpg A very slight cooling trend is apparent. Lucas, I am now wondering why you and other scientists think the Great Basin pika "is the first evidence of a small-medium sized mammal being extirpated by rising temperatures". Paul Cherubini El Dorado, Calif.
