Fifty-year population trajectory in a marginal American Pika (Ochotona princeps) population

Abstract

Abstract The American Pika (Ochotona princeps) has been considered a species at risk due to warming temperatures associated with climate change. Many life-history attributes of pikas contribute to the sensitivity of pikas to warming temperatures. Repeated censuses of a marginal (warm, low-elevation) population of pikas at Bodie State Historic Park, California, conducted from 1972 to 2022, are presented to track the population trajectory of pikas for a time period predating recent awareness of global warming to the present day, thus giving a comprehensive portrayal of how American pikas may be responding to climate change. The northern constellation of anthropogenic habitat patches (mine ore dumps) showed no decline in percent of patches occupied or in total number of pika territories over time, suggesting that pikas in that area have not been at risk of extirpation resulting from climate change. In contrast, the pika population in the southern constellation of patches showed significant declines in percent of patches occupied and number of pika territories occupied. That area was unoccupied for about a decade beginning in 2006, but was recently recolonized from the northern constellation of patches. The most likely cause of the initial decline and transient extirpation in the south appears to result from fragmentation and stochastic population dynamics, independent of climatic factors that we investigated. Assessments of climatic impacts on American pikas should take into account the dynamics documented in the Bodie pika population and its resilience over time.