Heterothermy
| Thermoregulation in animals |
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Heterothermy or heterothermia (from
Definition
Heterothermic animals are those that can switch between
Larger mammals (e.g. ground squirrels) and bats show multi-day torpor bouts during hibernation (up to several weeks) in winter.[1] During these multi-day torpor bouts, body temperature drops to ~1 °C above ambient temperature and metabolism may drop to about 1% of the normal endothermic metabolic rate. Even in these deep hibernators, the long periods of torpor is interrupted by bouts of endothermic metabolism, called arousals (typically lasting between 4–20 hours). These metabolic arousals cause body temperature to return to euthermic levels 35-37 °C.[1] Most of the energy spent during hibernation is spent in arousals (70-80%), but their function remains unresolved.
Shallow hibernation patterns without arousals have been described in large mammals (like the black bear,[2]) or under special environmental circumstances.[3]
Regional heterothermy
Regional heterothermy describes organisms that are able to maintain different temperature "zones" in different regions of the body. This usually occurs in the limbs, and is made possible through the use of counter-current heat exchangers, such as the