Autumn conditions as a driver of spring phenology in a free-living arctic mammal

Abstract

Several studies have shown that birds and mammals are breeding earlier in response to earlier spring conditions. Delay in the onset of winter should also affect reproductive timing and may allow for breeding later instead of earlier in spring, if extended autumns lengthen the season that food is available to offspring. Using 4 years of fine-scale environmental and phenological data of annual timing of hibernation and reproduction in two free-living populations of arctic ground squirrels in Northern Alaska, we show that the onset of winter snow-cover may influence females' spring phenology via its interaction with the timing of hibernation of young-of-the-year (YoY).