I went out to fill the "dinosaur feeders" in our front yard today. The late season snow cover is keeping the birds close to the easy sources of food. Under one of the shrubs was a white skull. I don't know if it died by flying into our window, or if it was a casualty of the annoying neighbor cats (keep your felines indoors, folks!)
What's cool is that you can see two key adaptations of a seed-eater. One is the thick beak - at least in comparison to the size of the bird. Cracking the hulls requires quite a bit of strength - the thicker beak helps crack those shells open. The other is the flexible "hinge" connecting the beak to the rest of the skull. This "kinetic skull" (specifically a process called prokinesis) allows the bird to pick up and manipulate irregularly-shaped seeds.
Here's a short slow-motion movie (shot with a Casio Exilim camera at 240fps).
Feeding Finch from Matt Kuchta on Vimeo.
Finch demonstrating its talent at cracking open seeds.
Based on the size of the skull and shape of the beak, I suspect it's a House Finch - and in deference to the Migratory Bird Act - I put the skull back under the bush.
I like the idea of having "dinosaur feeders" in my yard though. I think I'll have to keep that name.
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