This is Birdnode.

Have you ever watched Crows dive bombing a hawk or an eagle?

Several crows will gang up a tester a larger bird into departing their breeding territory.

Perhaps you've seen starlings or blackbirds do the same to crows.

When smaller birds join forces to ward off larger birds, it's called mobbing.

Its behavior, like calling family members for help, is used by many bird species.

The best time to observe mobbing is spring and early summer when breeding birds are trying

to protect their nests and young.

Barn swallows, which nest near humans, are a good example.

If a pair of swallows perceives a threat to their nesting territory, they sound the alarm.

Half a dozen neighboring swallows will arrive almost immediately to help scare away the intruder,

be it a house cat slinking into the garden or you venturing too close.

If you hear a ruckus and spot several crows circling and swooping toward a tall conifer,

it's a good bet that there's a raptor tucked in the tree, a hawk perhaps or an owl.

These birds know that there's strength in numbers and they've learned to join forces

to protect themselves.

For a link to a video of crows mobbing a bald eagle, visit our website, birdnow.org.

I'm Michael Stone.