14th Annual Smithsonian.com Photo Contest
Crested Serpent Eagle One Leg Standing
Birds' legs have an adaptation to minimize heat loss. The arteries that transport warm blood into the legs lie in contact with the veins that return colder blood to the bird's heart. The arteries warm the veins. And by standing on one leg, a bird reduces by half the amount of heat lost through its unfeathered limbs.
© Devarajan Karunanithi.
All rights reserved.
||May 11, 2016, 4:17 a.m.
||Canon EOS 1100D