National Geographic : 1946 Jul
Donald R. Griffin Close as Bananas in a Bunch Huddle Hibernating Bats With claws clamped in crevices in the rock of the cave, six bats cling snugly together to retain some of their heat. Bats must oxidize their fat slowly in winter to keep alive, since cold weather cuts off their one source of food-insects. In the five or six months' hibernation they lose a third of their body weight. Protruding from this mass of brown fur are the sleepers' ears and folded wings. Awakened, a Hibernating Bat Tries toSleep onaPencil Hind feet are adapted solely forhanging, head down, from rocks ortrees. Once the strongly curved claws arewell fixed inminute cracks, thebatcan relapse into a profound torporwithout danger offalling. Even ifitiskilled by freezing, tje claws remain attached. This onehad been hibernating ina Harvard laboratory. The whole foot canrotate 180°, likeaman's hand.