Biology Reference
In-Depth Information
Q I heard a tremendous racket from birds up in a tree last spring. When I got up
close, I could see that they were fluttering around an owl. Why do they make so
much noise? Shouldn't they try to keep quiet and stay away from the owl?
A
The birds you heard were uttering alarm calls after they noticed the owl. Many song-
birds recognize alarm calls not just of their own species, but of many other birds. They
may join a mob of birds making harsh scolding sounds while dive-bombing an owl,
snake, cat, or other predator. Together, they may drive the predator away, or at least dis-
tractorharassitsothatitwon'tdiscovertheirnestsoryoungnearby,orwheretheythem-
selves go to roost at night.
