The Fine Art of Dabbling

BirdNote^®

The Fine Art of Dabbling

Written by Bob Sundstrom

This is BirdNote.

[Gadwall calls, http://macaulaylibrary.org/audio/48809]

Picture a duck swimming slowly across a pond, skimming the water’s surface with its broad, spatulate bill slightly ajar. Dabbling, it’s called. [Gadwall calls, http://macaulaylibrary.org/audio/48809]

Along with the pond water, multitudes of tiny particles pass through the duck’s bill. Somehow it sorts out and swallows the tiny edible seeds and invertebrates, while rejecting the tiny, inedible bits of grit and mud and debris. To see how a duck pulls this off, we need to pry its bill open and look carefully inside. 

At the tip, and along the edges of the bill’s inner surfaces, lie many thousands of minute sensory receptors, of two kinds in particular. Receptors sensitive to touch, called Herbst corpuscles. And receptors sensitive to movement, called Grandry corpuscles. Both named for the European scientists who discovered them in the 19th Century.

Inside the bill, in just one square millimeter, there may be several hundred of these receptors. Not to mention lots of taste buds. So even though a duck doesn’t see what is passing through its bill as it dabbles, it can read what it's taking in, and eat or reject it with supreme acuity.

So. Dabbling is much more than simply straining the water. It’s truly a fine art. [Gadwall calls, http://macaulaylibrary.org/audio/48809, 0.04-.07].

Today's show brought to you by the Bobolink Foundation. For BirdNote, I'm Mary McCann.

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Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Gadwall calls [48809] recorded by Kevin J Colver.
BirdNote’s theme music was composed and played by Nancy Rumbel and John Kessler.
Producer: John Kessler
Executive Producer: Dominic Black
© 2015 Tune In to Nature.org    May 2018 / September 2022  Narrator: Mary McCann

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