ABSTRACT
Careful measurements of body temperatures in undisturbed animals over the entire hibernation season are fundamental to investigating the regulation of hibernation, its relationship to environmental variables, and sex differences in the timing and strategies of hibernation. The need for measurements of hibernation patterns in animals living under natural or semi-natural conditions is illustrated by the frequent citations of the classic study of Wang; however, in completely natural situations, variables such as temperature and food cannot easily be manipulated. This chapter introduces a useful compromise: outdoor enclosures built for collecting hibernation patterns using telemetry. The later immergence of males compared to females is unusual among hibernating Sciurids and may relate to the importance of food caches in arctic ground squirrel males, who end heterothermy in late March and early April when their environment is completely covered with snow which lingers until late May.
