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Written by Bob Sundstrom

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.

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.

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.

The soundscape featured in today’s show was recorded by Gordon Hempton and provided courtesy of .  We’d like to thank the Bobolink Foundation for making the show possible.

Song of the American Dipper and Riparian Zone Nature SFXs #119 and #17 recorded by Gordon Hempton of ; some stream ambient recorded by C. Peterson; Producer: John Kessler; Executive Producer: Chris Peterson