CURWOOD: It's Living on Earth, I'm Steve Curwood.
[MUX - BIRDNOTE THEME]
CURWOOD: Even where winter still holds its grip longer days and the first day of spring in less than two weeks promise that warmer days and the growing season will finally arrive. And then theres the promise we can find in flocks of wild birds. Heres Mary McCann with todays Birdnote.
Flocking and Foraging
[Winter flock of chickadees and kinglets]
MCCANN: Take a walk in a temperate woodland this month, and you might hear this chorus.
[Winter flock of chickadees and kinglets and Downy Woodpecker]
A closer look and listen reveals that this foraging flock includes several species of birds: chickadees, kinglets, and even a Downy Woodpecker.
Many bird species eat alone, so you might wonder why these birds have chosen to dine together.
Different species flocking together to find food, called commensal feeding, mutually enhances success. One species assists the foraging of others.
Black-capped Chickadee (Photo: Les Howard)
For example, in chickadee and woodpecker flocks, the woodpecker pecks off bark and moss, exposing grubs for its own consumption. But the pecking also stirs up flying insects that the chickadees swoop in to snatch.
The relationship also helps the woodpecker, because the extra eyes of the chickadees are on the lookout for predators. The watchdog chickadees alert the close-focused woodpecker when theres danger.
[Chickadee sounding the notes of danger]
Because these birds, foraging together, dont seek the same foods, the result is cooperativeor commensalrather than competitive feeding.
[More flock with Downy Woodpecker]
Im Mary McCann
A male Downy Woodpecker (Photo: Vitalii Khustochka)
Written by Frances Wood
Birdcalls provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Black-capped chickadee recorded by R.S. Little; Golden-crowned Kinglets by G.A. Keller, Downy Woodpecker call, by W.W.H. Gunn; and mixed flock by J. Storm.
Black-capped Chickadee 5 dee call recorded by C. Templeton
Photos: Black-capped Chickadee - Les Howard flickr.com/photos/leshoward/; Downy Woodpecker - Vitalii Khustochka flickr.com/photos/phenolog/; Golden-crowned Kinglet - Eugene Beckes flickr.com/photos/61210501@N04
Producer: John Kessler
Executive Producer: Chris Peterson
2015 Tune In to Nature.org Feb. 2015 Narrator: Mary McCann
CURWOOD: To find photos and more...flock on over to our website. Its LOE.org.
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