Superb Fairy-wrens teach their embryonic chicks a secret code. This "incubation call" contains a special note that will later serve as a password. When the chicks have hatched, this password enables the adult birds to identify their babies in the darkness of their domed nest. A species of Australian cuckoo lays its eggs in the wren’s nest, hoping to pawn off the task of parenting. But wren chicks learn their mother’s song and incorporate the password note into their begging calls.
Fairy-wrens Sing Secret Passwords to Their Unborn Chicks
Written by Todd Peterson
This is BirdNote.
[Song and alarm calls of Superb Fairy-wren]
It turns out some birds sing to their unhatched chicks. And for a good reason, too. By singing, Superb Fairy-wrens in Australia teach their embryonic chicks a secret code. “This ‘incubation call’ contains a special note that acts like a familial password.” 1/ Later, in the darkness of their domed nest, this password enables the adult birds to tell who is and who is not their baby.
Like cowbirds, a kind of Australian cuckoo lays its eggs in the wren’s nest, hoping to pawn off the task of parenting. But wren chicks learn their mother’s song, and incorporate the password note into their begging calls. If the call is right, the chick gets food. But if the cuckoo hatches first and pushes the wren eggs out, the parents may abandon the nest, “flying off to start a new family somewhere else.” 2/
[Song of Superb Fairy-wren]
The password note varies among different fairy-wren broods. It’s like a last name, “a signature of identity that unites a family. The females even teach these calls to their partners,” and use them “in their own begging calls when the males return to the nest with food.” 3/
Like Superb Fairy-wrens, does your family have a secret language?
[Song of the Superb Fairy-wren]
Linda Macaulay recorded this pair of Superb Fairy-wrens in New South Wales, Australia. For BirdNote, I’m Mary McCann.
Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Songs and alarm calls of Superb Fairy-wren  recorded by L. Macaulay.
BirdNote’s theme music was composed and played by Nancy Rumbel and John Kessler.
Producer: John Kessler
Executive Producer: Chris Peterson
© 2013 Tune In to Nature.org July 2018/2019 / June 2022 Narrator: Mary McCann
ID# SUFAWR-01-2013-07-17 SUFAWR-01
1, 2 & 3. “Fairy Wrens Teach Secret Passwords to their Unborn Chicks to Tell Them Apart from Cuckoo Impostors” by Ed Yong. Discover Magazine. Not Exactly Rocket Science. November 8, 2012. https://www.discovermagazine.com/planet-earth/fairy-wrens-teach-secret-…