Chickadee’s cheep is life-or-death warning

WASHINGTON – The chirp of the chickadee is charming to humans. To other chickadees, it can convey a lot of vital information.

When the little black-capped songbird whistles “chick-a-dee-dee” it can warn flock mates to watch out: A predator is near.

Christopher N. Templeton and colleagues recorded the chickadee songs, analyzed them by situation, studied the calls on acoustic instruments, and watched the birds react when the songs were played back. The researchers’ findings are reported in today’s issue of the journal Science.

“These birds are passing on way more information than anyone ever dreamed possible, and only by carefully looking at these calls can we really appreciate how sophisticated these animals are,” Templeton said in a telephone interview.

“They change a bunch of different features about the call, subtle acoustic features, the spacing between the notes, things we can’t hear,” he said.

One thing humans can hear, Templeton said, is the number of “dee” notes at the end of the call.

“The more they add, the more dangerous the predator,” he said.

The familiar “chick-a-dee” can indicate a stationary predator.

Variations can convey how dangerous it is, whether it flies or is a snake or a mammal such as a ferret, and where it is, he said.

“We had no idea that any animal was able to distinguish between predators that seem similar,” Templeton said. “It’s life or death for them. It’s just a fun bird-watching tool for us.”