Mobbing: When Smaller Birds Join Forces to Fend Off Larger Birds

There’s strength in numbers, and many species have learned to work together to protect themselves.

This audio story is brought to you by BirdNote, a partner of the National Audubon Society. BirdNote episodes air daily on public radio stations nationwide.


This is Birdnote.

Have you ever watched crows dive-bombing a hawk or an eagle? Several crows will gang up and pester 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.” This 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 housecat 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,, I’m Michael Stein.



Bird sounds provided by The Macaulay Library at the Cornell Lab of Ornithology, Ithaca, New York. American Crow mobbing sounds [36942] recorded by A.B. Vandeburg. Barn Swallow call [106593] recorded by R.S. Little.

BirdNote’s theme music was composed and played by Nancy Rumbel and John Kessler.

Producer: John Kessler

Executive Producer: Chris Peterson

Narrator: Michael Stein

Written by Frances Wood

© 2015 Tune In to     July 2018