| 摘 要： | 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 shortsummer 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 for regions containing pikas. Mild winter temperatures at these pika locations show that long-winter temperatures and snow accumulation associated with typical habitat may not be 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 change on 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.
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