As bears extend their range further south in Michigan, the DNR study gathers scientific data for effective management. One radio-collared bear conveniently wintered her family in a cedar swamp less than fifteen minutes from the Au Sable campus. Rendezvousing in the early morning light, the students and wildlife workers located the nearest road access to the cedar swamp. Picking our way over fallen logs and around balsam fir and red cedar, the Au Sable contingent walked a short ways into the swamp, then waited while DNR officials went ahead to locate the den and tranquilize the bears. The popular perception of ursine hibernation imagines a winter-long, deep sleep.
Bears actually spend the majority of wintertime awake, albeit in a metabolically-slowed state.
In this instance, the mother bear was conscious, but sufficiently lethargic that she allowed herself to be tranquilized along with her cubs. On signal that all was ready, the students then moved ahead and were able to glimpse the three bears huddled in their den beneath a fallen cedar tree. The DNR biologists then removed the bears from the den, placing them on mats prior to taking measurements. The two yearlings weighed 60-65 lbs., and the mother 170 lbs. The DNR was uncertain how many bears they would find wintering in the den.