The twittering of birds can fill any spring or summer day with music: All you have to do is open your window to hear crows “caw,” killdears call “kill-deah! kill-deah!” and chickadees sing “chickadee-dee-dee.”
But come back an hour later, and you’ll still hear them singing the same song, repeatedly. That’s because they’re hard at work. These avian singers tend to be male, and are crooning their hearts out to guard their territory and attract a mate, said Gail Buhl, education program manager at the Raptor Center at the University of Minnesota.
On the territorial front, the melody says, “This is my area and I’m letting everyone else, especially every other male in the area, know that this is my space,” Buhl told Live Science.
Dispatches From The Front 