Leader of the Flock

Every time I see a large flock of birds flying about and erratically changing directions, I wonder if there's one bird that decides which direction the flock should go. Can you answer this?

—Betty Brockett, South Haven, Michigan

George: In some bird species, one bird does lead a flock; geese are a good example. But with smaller birds, like red-winged blackbirds, the flock takes cues from different birds as they fly. While there's much we still don't know about flock movement, research into this subject indicates the birds watch each other and change direction accordingly, sort of like people doing "the wave" at a sporting event. A flock may change directions for a variety of reasons, including shifting winds, the appearance of a predator or the discovery of food or protective habitat.