Weather determines daily activity pattern of an endemic chipmunk with predictions for climate change

Abstract

Environmental changes can affect an animal's activity pattern and influence fitness. Our goal was to understand the influence of weather on daily activity pattern and assess potential impacts of climate change on activity. We used the Organ Mountains Colorado chipmunk (Neotamias quadrivittatus australis) as a case study. To record activity, we deployed 19 remote cameras at locations occupied by the chipmunk for one year. First, we estimated seasonal variation in daily activity pattern using circular kernel density. Second, we tested if weather influenced activity in each season using Poisson regression in a model selection framework. Third, we predicted the impacts of future climate (RCP8.5 high-emissions scenario) on activity using the best weather model for each season. We found that times and modality of peak activity varied seasonally. Temperature influenced intensity of daily activity in late spring, early summer, monsoon, late fall, and winter, while precipitation influenced intensity of daily activity in early spring and early fall and relative humidity influenced intensity of daily activity in early and late fall. Intensity of daily activity was predicted to increase by 89% in winter and decrease by 51% in early summer under future (2050) climate. The predicted future increase in daily activity in winter may negatively affect fitness because small mammals have higher survival while hibernating. The predicted future decrease in daily activity in early summer may negatively affect fitness due to reduced reproductive output. Losing or gaining time for activity because of shifting climatic conditions could have severe consequences to fitness.