Nature & Environment
Animals at the extremes: hibernation and torpor
...manage on stored energy reserves, mainly of fat, for extended periods by lowering their T b by only 2–6° C. The availability of food is another factor: a number of small birds, for example the American goldfinch (Carduelis tristis*; Figure 2) can survive in winter temperatures down to −60° C, remaining active and maintaining T b with a huge (in excess of 500% over...
