Climate change is altering the physiology and phenology of an arctic hibernator

Climate warming is rapid in the Arctic, yet impacts to biological systems are unclear because few long-term studies linking biophysiological processes with environmental conditions exist for this data-poor region. In our study spanning 25 years in the Alaskan Arctic, we demonstrate that climate change is affecting the timing of freeze-thaw cycles in the active layer of permafrost soils and altering the physiology of arctic ground squirrels (Urocitellus parryii). Soil freeze has been delayed and, in response, arctic ground squirrels have delayed when they up-regulate heat production during torpor to prevent freezing. Further, the termination of hibernation in spring has advanced 4 days per decade in females but not males. Continued warming and phenological shifts will alter hibernation energetics, change the seasonal availability of this important prey species, and potentially disrupt intraspecific interactions.

Automated summary

In our 25-year study in the Alaskan Arctic, we found that climate change is affecting freeze-thaw cycles in permafrost soils and altering the physiology of arctic ground squirrels. Soil freeze has been delayed, causing the squirrels to delay heat production during torpor. The termination of hibernation in females has also advanced 4 days per decade. These changes can have significant impacts on energetics, prey availability, and intraspecific interactions.