Quirks and Quarks

Songbird parents manipulate their chicks out of the nest before they're ready to go

Parents will lure their fledglings out of the nest with food or by calling them

Parents will lure their fledglings out of the nest with food or by calling them

Radio-tagged fledgling Common Yellowthroat (Todd Jones)

There comes a time in most songbird parents' lives when their chicks have grown up — a bit — and though they aren't yet old enough to make it on their own, their parents give them the boot out of the nest anyway.

Mike Ward, an associate professor of avian ecology at the University of Illinois at Urbana-Champaign, said the first couple of days out of the nest is the most dangerous time for young songbirds.

He said more fledglings die outside of the nest than in it, which led him to wonder why the chicks would even leave in the first place.

In a study of 18 songbird species across the United States, Ward and his colleagues — as well as many volunteers — monitored nests and radio tagged the fledglings to figure out what's happening.

It turns out the parents were manipulating the young fledglings out of the nest by either calling to them or luring them out with food, to separate the chicks on nearby branches, trees and grass where the songbird parents might help them for a couple of weeks.

When the researchers tallied their results, they discovered that by separating the chicks, songbird parents increase their chances of at least one offspring surviving to the next generation. 

Even though there's a greater chance each chick may die outside of the nest, this is a classic example of songbirds not wanting to put all of their eggs in a single basket to risk a predator eating them all.

Produced and written by Sonya Buyting