The Social Lives of Birds'If I were to read any book on what birds are all about, I could not recommend one more than this one' Bernd Heinrich, author of Mind of the Raven In The Social Lives of Birds, evolutionary biologist Joan Strassmann examines what it means for birds of a feather to flock together. Some birds sleep together. Some join the foraging groups of other species. Some are only social during the breeding season, forming nesting colonies in trees, cliffs, and