Air Date: Week of October 4, 2013

American Dipper adult and fledgling. (© Tom Grey)

The American Dipper is a favorite bird of the west, but exactly why dippers dip is a bit of a mystery. Michael Stein reports.

Transcript

CURWOOD: We have a much more soothing kind of story now - the mystery of exactly why a familiar bird of the American west does what it does. Michael Stein has our BirdNote®.

[WATER RUSHING, SOUND OF CHIRPING]

STEIN: An American Dipper calls across a rushing mountain stream. Its rotund, stone-gray body bobs rhythmically up and down, its feet firmly planted. The bird’s white-feathered eyelids flash like a semaphore.

[CHIRPING AMERICAN DIPPER]

American Dipper swimming with food. (© Tome Grey)

So why do dippers dip?  Let’s consider three theories: One suggests the dipper’s repetitive bobbing against a background of turbulent water helps conceal the bird’s image from predators. A second asserts that dipping helps it sight prey beneath the surface of the water. A third theory holds the most promise. Dipping, as well as the rhythmic flicking of those flashy white eyelids, may be a mode of visual communication among American Dippers in their very noisy environment. That dippers make exaggerated dipping movements during courtship and also to threaten aggressors lends support to this theory.

[WATER RUSHING IN MOUNTAIN STREAM]

So if one day, as you muse alongside a mountain stream and an American Dipper bobs and winks in your direction, don’t take it personally. It’s probably beckoning to another dipper upstream.

I'm Michael Stein.

American Dipper (© Tom Grey)

CURWOOD: There are photos of dipping dippers at our website, LOE.org.

[birdnote.org/show/why-dippers-dip
Written by Bob Sundstrom
Song of the American Dipper and Riparian Zone Nature SFXs #119 and # 17 recorded by Gordon Hempton of QuietPlanet.com
Some stream ambient recorded by C. Peterson
Producer: John Kessler
Executive Producer: Chris Peterson
© 2013 Tune In to Nature.org September 2013 Narrator: Michael Stein]

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