Considerable research is aimed at developing predictions of ecosystem responses to climate change, focusing on the spatial scale, such as range shifts and contractions, as well as activity restrictions to shaded microhabitats. On the other hand, the ability of species to shift their activity times at the diel scale and consequently to alter the environment in which their activity takes place is largely ignored. We developed a framework that explores how shifts in activity patterns may buffer impacts of climate change. To demonstrate our framework, we simulated diurnal and nocturnal rodents across North America, and calculated the predicted activity costs during concurrent and future climates.
Results/Conclusions
We found that future summers may decrease the energetic demands of nocturnal mammals while increasing water demands of diurnal mammals. Climatic projections suggest that vegetation cover and water availability will decrease under future climate, particularly when water demands are expected to increase the most, limiting the ability of diurnal animals to restrict activity to shaded microhabitats and to keep a positive water balance. Our analysis shows that by shifting to nocturnality, diurnal mammals may eliminate the high water costs of future summers. Future research should explore the role of the diel time axis as an ecological resource when predicting the impacts of climate change.