Birds like finches, chickadees and this Northern Cardinal love sunflower seeds, but each species uses a different strategy to extract the meat. When a finch plucks a sunflower seed from the feeder, it uses its tongue to maneuver the seed lengthwise into a groove on its beak. 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. But chickadees lack the heavy duty, seed-slicing beak of a finch. Instead, they hammer and chip the hull open with the tip of the bill to extract the goods.
Beak Meets Sunflower Seed
Chickadees lack the heavy duty, seed-slicing beak of a finch. [Black-capped Chickadee call, http://macaulaylibrary.org/audio/98802, 0.06-.09] 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.