Heterothermic Heterothermic Fazil Kucuk Category="Physiology"Heterothermic (from Greek: hetero = "other" thermy = "heat.") is a physiological term referring to creatures who vary between homeothermy and poikilothermy throughout the day, or year. More often than not, it is usually used as a way to dissociate the fluctuating metabolic rates seen in some small mammals & birds (e.g. bats & hummingbirds), from those of traditional cold blooded animals. In many Bat species, body temperature and metabolic rate, are elevated only during activity. When at rest, these animals reduce their metabolisms drastically, which results in their body temperature dropping to that of the surrounding environment. This makes them homeothermic when active, and poikilothermic when at rest.

Note: Strictly speaking, heterothermy is just a variant of poikilothermy, as the internal body temperature still varies.

Regional heterothermy

This is a far more specific type of heterothermy. It is also a more common one seen in animals today. It describes creatures that are able to separate the temperature in different regions of the body. This usually occurs in the limbs, and is made possible through the use of counter current heat exchangers. These exchangers keep warm blood from entering into the extremities. Penguins and many arctic birds use these exchangers to keep their feet at roughly the same temperature as the surrounding ice. This keeps the birds from getting stuck on an ice sheet. Other animals, like the Leatherback Sea Turtle, use the heat exchangers to gather, and retain heat generated by their muscular flippers.

References

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External links

Thermobiology of bats