It's funny how you can observe something for hours and not realize what you are seeing until someone explicitly points it out to you.

In one passage of "The Nature of Oaks" Tallamy points out that bird behavior at a bird feeder differs from species to species. Finches will stay and stack on seeds, eating as many as they can. Chickadees will grab a seed and then disappear to hide it (perhaps in a nearby tree).

Son-of-a-gun, it's true! As I sit in our library, staring at our own bird feeder, I see exactly this behavior. But until I had read a book, I'd never really noticed what was happening.