Other OccupantsPicture of the Week: Cowbird Egg in Eastern Bluebird Nest

Picture of the Week: Cowbird Egg in Eastern Bluebird Nest

Cowbird egg in eastern bluebird nest
Photo by Bet Zimmerman Smith

I found this Brown-headed Cowbird egg in an Eastern Bluebird nest. (See full resolution version.) The nest was in a Gilwood box. I rarely see cowbird eggs in my boxes. I make sure the entrance holes are not enlarged, which may deter them somewhat.

Cowbirds are parasitic nesters. They find an active nest, and before incubation begins they remove one of the host’s eggs and replace it with their own, leaving the host bird to raise their young (unless the eggs are detected and removed by the host.) Read more about these fascinating creatures.

Also see photo of a Cowbird egg in a sparrow nest.

References and More Information:

Previous Pictures of the Week: © Original photographs are copyrighted, and may not be used without the permission of the photographer. Please honor their copyright protection. If you would like to use a photo for educational purposes, you can contact me.

You cannot begin to preserve any species of animal unless you preserve the habitat in which it dwells. Disturb or destroy that habitat and you will exterminate the species as surely as if you had shot it. So conservation means that you have to preserve forest and grassland, river and lake, even the sea itself. This is vital not only for the preservation of animal life generally, but for the future existence of man himself—a point that seems to escape many people.
-Gerald Durrell, The Nature Conservancy


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