What Is THAT Bird?!

As I've mentioned before, we are enthusiastic backyard birders around here and have been for years. Last week, however, we were stumped when this bird showed up at our tray feeder. At first, it sat on the feeder's edge, cheeping. A few minutes later, we spied a much smaller white-throated sparrow (tan form) feeding it. The plot thickens! What was this young bird? Obviously not a white-throated sparrow -- the colorings and marking were different, and the baby was already larger than the parent! And why was the sparrow feeding it?




Dh suggested the baby bird's mother had laid her eggs in another bird's nest. That sounded plausible. I flipped through my handy Stokes Beginner's Guide to Birds: Eastern Region and found that the mystery bird resembled the female brown-headed cowbird. I also learned that female cowbirds lay their eggs in the nests of other species instead of building their own nests. Success!


I checked the brown-headed cowbird entry at Cornell University's All About Birds website. It turns out that brown-headed cowbirds are small blackbirds. They are also our continent's most common brood parasite, meaning females lay their eggs in other species' nests, and these "foster parents" then raise their young. Talk about hands-off parenting!


The little one now comes to our feeder several times a day. She's learned to eat on her own, and I no longer see her with the sparrow foster parent. I wonder if the sparrow ever noticed that her "baby" was bigger than she!