I haven't read the book, but I believe it's been known for a while that crows can *use* tools (pick up a twig to get at food), but only discovered in the past few years that they can actually *fashion* them (bend the wire to a shape that is better at getting the food).
Alex, I thought of that connection right after I posted this. Such a good joke setup! Then I figured I could rely on you (or maybe some other astute commenter) to bring it up. I think what they really see is a stone in a face.
Doo dooo be-doo-doo
--Moe Shadypalms