Baby Bird Passwords

June 19, 2014

BOB HIRSHON (host):

A bird’s secret code. I’m Bob Hirshon and this is Science Update.

Superb fairy wrens flickr David Jenkins — Male and female superb fairy wren. (David Jenkins/flickr)

Cuckoos are famous for laying their eggs in other birds’ nests, pawning off all the care and feeding of their offspring to a hapless host parent. But superb fairy wrens have evolved a defense against the freeloaders. According to behavioral ecologist Sonia Kleindorfer of Flinders University in Australia, mother fairy wrens sing to their eggs while they’re in the nest – like this:

(Mother incubation song)

After the babies hatch, they have to sing a special call note that matches key elements of that song in order to get fed. For instance:

(baby bird call notes)

KLEINDORFER:

Whether you learn the password correctly will determine whether or not you will live or die.

HIRSHON:

She and her colleagues discovered that each nest has a different password call.

Baby cuckoos often don’t get the password quite right, and are often rejected by the host parents.

HIRSHON:

I’m Bob Hirshon, for AAAS, the science society.