Webbed Feet Are an Evolutionary Hit
From geese and gulls to penguins and puffins, these birds have perfectly adapted to life on the water.
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Transcript:
This is BirdNote.
Webbed feet are ideal for birds that swim, on the water鈥檚 surface or under. In fact, they鈥檙e such a nifty adaptation that they evolved, independently, in several bird groups.
Ducks and geese have them, as do gulls, cormorants, loons, pelicans, penguins, puffins and boobies.
Experiments suggest that a triangular webbed foot is beautifully designed to propel a bird, or other creature, through the water.
The toes and webs spread out as the bird pushes its foot backward. Then as the bird pulls its foot forward, the toes fold together, to minimize resistance. And many birds have mastered a stroke that any human swimmer might envy. A bird may lift its foot away from its body on the forward stroke, actually giving itself a little extra lift and speed.
Four hundred different species of birds have webbed feet. And a parallel adaptation shows up in other creatures that spend time in the water鈥攍ike otters, frogs and salamanders.
It鈥檚 clear that webbed feet have been a big evolutionary hit. Regardless of who鈥檚 wearing them.
For BirdNote, I鈥檓 Michael Stein.
Today鈥檚 show brought to you by the Bobolink Foundation.
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Credits:
Written by Bob Sundstrom
Producer: John Kessler
Executive Producer: Sallie Bodie
Editor: Ashley Ahearn
Associate Producer: Ellen Blackstone
Assistant Producer: Mark Bramhill
Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Gadwalls, Canada Geese, and Mallard recorded by T. Johnson.
BirdNote鈥檚 theme was composed and played by Nancy Rumbel and John Kessler.
漏 2020 BirdNote March 2020 Narrator: Michael Stein
ID# feet-02-2020-03-30 feet-02