Crow Faces (Image from NPR)

NPR has a great web feature about crows recognizing individual human faces. There is a video, a podcast, and a fun game testing if you can recognize individual crow faces.

The basic story:
A crow researcher asked students to catch and tag crows while wearing a caveman mask. Then he asked different students, of a variety of shapes and sizes (who never caught or tagged a crow), to wear the mask among the same crows. No matter who wore the mask, the crows reacted to it by cawing danger warnings to other crows demonstrating they were recognizing the facial features of the mask.