AMERICAN PIKAS INHABIT LOW-ELEVATION SITES OUTSIDE THE SPECIES' PREVIOUSLY DESCRIBED BIOCLIMATIC ENVELOPE

It has been suggested that Nearctic pikas (Ochotona spp.) are good biogeographic indicators of regions containing rocky, mesic, and cool habitat characterized by long winters and short summers. I examined whether populations of pikas inhabiting distinct low-elevation locales (121-255 m) are faithfully restricted to long-winter and short-summer conditions by monitoring the climate associated with American pikas (Ochotona princeps) in the southern part of the Columbia River Gorge, Oregon. Ambient air temperatures and weather conditions in the vicinity of 4 pika-occupied rockslides were monitored with remote temperature loggers and weather stations from June 2000 to June 2001. Temperatures were compared to long-term averages recorded within the area. I detected pikas inhabiting locales where some temperatures lie outside of the limiting climatic Values previously calculated fur regions containing pikas. Mild winter temperatures at these pika locations show that long-winter temperatures and snow accumulation associated with typical habitat may not lie requirements for pikas in some low-elevation habitat. When using climatic conditions experienced by extant pikas to estimate local paleoenvironments surrounding fossil sites and to anticipate effects of climate charge 011 future pika distributions, I determined that pika sites in the Columbia River Gorge indicate that the association of pikas with long-winter habitat Should be considered uncertain. These results highlight the need for further investigation into how local temperatures affect the distribution, behavior, and persistence of low-elevation pikas.