Most people have witnessed it at one time or another. A small bird dives at another, larger bird. Or perhaps a lot of smaller birds vocalize in the same tree in which a larger bird happens to be perched. This behavior is called mobbing; mobbing behavior includes diving, close passes and even physical contact, while being careful not to come into harm’s way.

The behavior is undertaken by birds to protect their territories and any food sources by chasing the target off. Mobbing also takes place during the breeding season to protect nests and young.

Mobbing birds frequently seen in the region include chickadees, titmice, blackbirds and crows. The targets include falcons, hawks, owls and eagles. Some of the mobbers, such as crows, are frequently on the receiving end of a mobbing episode, especially when near a nest; crows are known to raid nests and grab a young bird and fly off with it.

After a couple of decades spent monitoring bald eagle nests in the region, I have seen many species of smaller birds that have close encounters with breeding eagles. Eagle territories frequently overlap with breeding territories of other bird species; since both the eagle and the mobbing birds are breeding, the interactions can be interesting.  In this column, I have included a few images of these interactions, and information on how the eagles cope with mobbing behavior.