Cowbirds: Engaging in 'Mob' Behavior?

  • Playlist
  • Download
  • Embed
    <iframe src="http://www.npr.org/player/embed/7819826/7819827" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

Cowbirds famously deposit their eggs in the nests of other birds, allowing surrogate parents to raise their young. But why do the other birds put up with it? New research suggests the cowbirds are also intimidating enforcers.

(Soundbite of music from "The Godfather")


Watch out for those cowbirds. They may make you an offer you can't refuse. Scientists writing in this week's online edition of Proceedings of the National Academy of Sciences report what they call Mafia behavior among the species. Cowbirds are notorious for leaving their eggs in the nest of other birds to be raised. And researchers have often wondered why the put upon hosts put up with new mouths to feed. It turns out if the birds don't accept the cowbird's eggs, the cowbirds just might trash their nest.

For four years Jeffrey Hoover and Scott Robinson of the Florida Museum of Natural History watched cowbirds as they dumped their eggs into warblers' nests in southern Illinois. When the researchers removed the cowbird eggs from the warblers' nests they found that more than half the time the cowbirds came back and tossed those nests like a Caesar salad. Say ya, warbler. You got a mighty nice nest here. Geez, I'd hate to see some guy mess it up. Know what I mean?

Copyright © 2007 NPR. All rights reserved. Visit our website terms of use and permissions pages at www.npr.org for further information.

NPR transcripts are created on a rush deadline by a contractor for NPR, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of NPR’s programming is the audio.

Related NPR Stories



Please keep your community civil. All comments must follow the NPR.org Community rules and terms of use, and will be moderated prior to posting. NPR reserves the right to use the comments we receive, in whole or in part, and to use the commenter's name and location, in any medium. See also the Terms of Use, Privacy Policy and Community FAQ.

NPR thanks our sponsors

Become an NPR sponsor

Support comes from