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:
“And as he sowed, some seed fell on the path, and the birds came and ate it up.”
—Bible: New Testament, Mark 4:4.
“Spring, the sweet spring, is the year’s pleasant king;
Then blooms each thing, then maids dance in a ring,
Cold doth not sting, the pretty birds do sing,
“Cuckoo, jug-jug, pu-we, to-witta-woo!””
—Thomas Nashe (1567–1601)
“The kiss of the sun for pardon,
The song of the birds for mirth,—
One is nearer God’s heart in a garden
Than anywhere else on earth.”
—Dorothy Frances Gurney (1858–1932)