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:
“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)
“Calico Pie,
The little Birds fly
Down to the calico tree,
Their wings were blue,
And they sang “Tilly-loo!”
Till away they flew—
And they never came back to me!”
—Edward Lear (1812–1888)
“soon the birds and ancients
Will be starting to arrive, bereaving points
South.”
—Louise Glick (b. 1943)