Until recently, hibernation was thought to occur solely among animals in the Northern Hemisphere. Only over the past ten years has the process been documented and studied in animals of the south.
One of the subjects of that study is the eight-inch-long mountain pygmy possum. Some 2,000 of them remain in the wild--living in boulder- strewn fields one mile high in the Australian Alps. Zoologist Fritz Geiser of the University of New England in Australia has been monitoring these animals since last year, when he discovered that, come winter, they curl up into tight balls, cool down, and hibernate. Geiser fitted ten pygmy possums with temperature-sensitive radio transmitters and recorded their temperature for five months. When they hibernate, he found, their body temperature drops from 96 to 35 degrees and their metabolic rate falls to 1 percent of its normal level. The body temperature of bears, in comparison, typically drops ...
