Common Eiders Favor Close Relatives

BirdNote^®

Common Eiders Favor Close Relatives

Written by Gordon Orians

This is BirdNote. 

[Common Eider Nosey Gossip Sounds…]

Can birds tell who their relatives are? Recently, researchers at the University of Gothenburg in Sweden tried to find out. But first - a bit of background. 

Female birds of some species try to save energy by tricking others of the same species into incubating their eggs. They're known as brood parasites. If a bird incubates the eggs of unrelated females, she has more babies to care for, but gains no genetic benefits. If the eggs are laid by a close relative, though, the host may gain by favoring the spread of genes they share. [Common Eider Nosey Gossip Sounds…]

To try to discern whether birds can tell the difference, researchers filmed interactions at 65 nests of the Common Eider duck. They recorded whether there were fights when a female other than the owner of a nest tried to lay an egg there. And it turns out that close relatives caused no aggression. But, an unrelated female often did cause conflict if she tried to lay an egg there. 

So - female Eiders appear to act differently toward close relatives. 

Exactly how they recognize them, though, remains unknown. [Common Eider Nosey Gossip Sounds…]

For BirdNote I'm Mary McCann. 

Support for BirdNote comes from the Cornell Lab of Ornithology, presenting its new "Bird Photography” online course, featuring Melissa Groo. Learn more at academy.allaboutbirds.org

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Common Eider sounds [180423] recorded by Stein Nilson at Longyearbyen, Spitsbergen, Svalbard, sourced from Xeno-Canto : http://www.xeno-canto.org/180423.
BirdNote’s theme music was composed and played by Nancy Rumbel and John Kessler.
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© 2015 Tune In to Nature.org    May 2015/2020   Narrator: Mary McCann

ID#            COEI-01-2015-05-18COEI-01