Cowbird vs Chipping Sparrow

We received an email from Larry & Angie in Innisfail a while ago, asking for help identifying a bird in their yard. They were confused because this bird was acting like a baby sparrow, being fed by an adult sparrow but appeared to be bigger than the adult. Their photogenic picture does a wonderful job of showing a juvenile Brown-headed Cowbird in action, and the difference in size between the two species.

As Matthew mentioned in his July Cowbird Catastrophe post on this blog, Cowbirds do not look after their own eggs, but lay them in the nests of other species. This poor Chipping Sparrow has already been outsized by this demanding youngster, and continues to burn up energy finding enough food for it. As Cowbird eggs hatch sooner than those of other birds and fledglings are known to eject the nest occupants, it’s likely this Chipping Sparrow did not raise any of his own young this year.

Posted by Pat Bumstead

2 thoughts on “Cowbird vs Chipping Sparrow

  1. I’m always struck by the beauty of a male brown-headed cowbird. Far from being a catastrophe, I think it is interesting to see how this species has found a way to have its young raised by other birds.

    • I agree – it has to be one of the most successful adaptations in the bird world. It really intrigues me how the young recognize their own species. If there weren’t so many other (human-caused) threats to songbirds, more people would probably admire cowbirds too.

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