How Do Finches Shell Sunflower Seeds so Quickly?

Transcript: ​

This is BirdNote.

Birds like finches and cardinals love sunflower seeds, which they take into their stout, triangular beaks one after the other. In the blink of an eye, they extract the nutritious contents, and they do it so fast, it looks like a magician’s sleight of hand. But if we magnify the process and slow it down, we can see how it works. 

First, if we look inside a finch’s beak, we see a groove that runs the length of the beak on the cutting edge of the upper half. The lower half of the beak slides into it perfectly.  

When a finch plucks a sunflower seed from the feeder, its uses its tongue to maneuver the seed lengthwise into that groove. As it closes its beak, a slight back and forth action slices open the hull, and a small sideways movement husks the seed, while the tongue may help extract the kernel. Now it’s quickly on to the next seed: maneuver, slice, husk and extract, swallow.

Chickadees lack the heavy duty, seed-slicing beak of a finch. But they still partake of countless sunflower seeds. A chickadee takes one sunflower seed at a time from the feeder, flies to a nearby perch where it can hold the seed atop a branch, then hammers and chips the hull open with the tip of the bill to extract the goods.

For BirdNote, I'm Michael Stein.