Recent climate change is altering the phenology of spring green-up and the onset of winter, and can act as an additional strain on threatened populations, especially during energetically demanding periods such as winter. By using regional weather data, and data on the availability of foods within home ranges of individuals, we clarified the links between environmental conditions and denning behaviour of grizzly bears. In part because of its simplicity, our approach is an attractive option to investigate the links among environmental conditions and phenology, and the timing of hibernation or other behaviours for large mammals. Our results suggest that for grizzly bears, den entry is more driven by food availability while den exit is more linked to weather. These results have implications for the long-term conservation of grizzly bear populations because extended growing seasons and mild meteorological conditions expected under future climate conditions will likely result in shorter denning periods. While our approach remains applicable to a wide range of species utilizing dens, we provide the necessary first steps to understand the potential impacts of climate change on the denning behaviour of grizzly bears. This study offers the first quantitative evidence of a relationship between autumn food availability and denning behaviour for grizzly bears, and encourages future investigations on the importance of food resources for denning species in an increasingly warming world.
Pigeon KE, GB Stenhouse, SD Côté (2016) Drivers of hibernation: Linking food and weather to denning behaviour of grizzly bears. Behav Ecol Sociobiol. 70: 1745 – 1754