Birds
In birds with webbed feet, retia mirabilia in the legs and feet transfer heat from the outgoing (hot) blood in the arteries to the incoming (cold) blood in the veins. The effect of this biological heat exchanger is that the internal temperature of the feet is much closer to the ambient temperature, thus reducing heat loss. Penguins have them also in the flippers and nasal passages.
Read more about this topic: Rete Mirabile
Famous quotes containing the word birds:
“The sea was wet as wet could be,
The sands were dry as dry.
You could not see a cloud, because
No cloud was in the sky:
No birds were flying overhead—
There were no birds to fly.”
—Lewis Carroll [Charles Lutwidge Dodgson] (1832–1898)
“While he hears in every spring
How the birds do chirp and sing:
Or before the hounds in cry
See the hare go stealing by:
Or along the shallow brook,
Angling with a baited hook,
See the fishes leap and play
In a blessed sunny day:”
—Nicholas Breton (1542–1626)
“soon the birds and ancients
Will be starting to arrive, bereaving points
South.”
—Louise Glick (b. 1943)