Why Do Birds Rest on One Leg?

Their feet get cold, too!

This audio story is brought to you by BirdNote, a partner of the National Audubon Society, and is a special excerpt from the recently released anthology BirdNote: Chirps, Quirks, and Stories of 100 Birds from the Popular Public Radio Show. We'll be sharing selections from the book all April. And remember, you can catch BirdNote episodes daily on public radio stations nationwide.


Picture a duck—say, a Mallard—standing on just one leg. It’s a wonder it doesn’t tip over. 

Long-legged herons—as well as short-legged ducks, geese, hawks, and gulls—often roost in a peg-legged stance while keeping the other leg tucked up into their body feathers for warmth.

On the beach, look for shorebirds balanced on one leg. On rare occasions, you may see sandpipers travel short distances, hopping crazily. Birds have adaptations to manage heat loss. The arteries that transport blood into the legs lie in contact with the veins that return blood to the bird’s heart. The warm arteries heat the cooler veins. Because the veins also cool the arteries, the bird’s feet are closer to environmental temperature and thus don’t lose as much heat as they would if they were at body temperature.

And as for standing on one leg, do the math: a bird with its foot tucked up reduces by half the amount of heat lost through its unfeathered limbs.

During winter’s cold, look for sparrows and juncos fluffing out their feathers to cover both legs. And for extra warmth, they tuck their beaks under their shoulder feathers, but not under their wings, as people often say.



Bird sounds provided by The Macaulay Library at the Cornell Lab of Ornithology, Ithaca, New York. Mallards recorded by A.A. Allen [3420], Glaucous-winged Gull [3350] recorded by A.A. Allen, and chipping of Dark-eyed Juncos [130987] recorded by W.L. Hershberger.

Producer:  John Kessler

Written by: Frances Wood 

Narrator: Michael Stein

© 2017 Tune in to Nature.org    

BirdNote: Chirps, Quirks, and Stories of 100 Birds from the Popular Radio Show, edited by Ellen Blackstone, illustrations by Emily Poole, Sasquatch Books, 205 pages, $22.95. Buy it online at Powells.