Allen's Rule
Endothermic animals (warm-blooded animals like mammals and birds) living in
colder climates tend to have shorter limbs, ears, and other appendages to
minimize heat loss. In contrast, animals living in warmer climates tend to have
longer limbs, ears, and other appendages to increase heat loss and help regulate
their body temperature. This adaptation helps animals conserve heat in cold
environments and dissipate heat in warm environments, improving their overall
survival and fitness. Examples include:
Arctic foxes having shorter ears and
limbs compared to desert-dwelling foxes. (See Image)
Polar bears having smaller ears and
shorter limbs compared to tropical bears.
