The Brown-Headed Cowbird doesn’t look like much…until the light hits it just right. Then the male radiates a color and sheen that is stunning. Females, like many bird species are more drab, which is normally nature’s way of protecting them during nesting. Funny thing about Cowbirds though…they don’t really make a nest…in fact, they don’t even raise their young.
OK, as weird as that sounds, it’s true. Cowbirds are “parasitic” nesters. The female will lay an egg in some other birds nest…maybe it’s a cardinal, or robin for example. The host will incubate, hatch, and raise this Cowbird as one of its own. Cowbird chicks tend to grow very fast, faster than most other birds, which is another way it ensures a higher degree of survival.
Ornithologists think this parasitic behavior was a way to help Cowbirds survive in a transient life on the prairies and for the most part it seems to have worked. This bird, despite its nesting tactics, is not an invasive species, but an American original…in fact it’s as old as the Buffalo herds it typically followed on the plains. With the great beasts once numbering in the millions you can bet there were plenty of Cowbirds around too.
Today, they don’t pose too many problems for other bird populations…in a few instances they have been managed due to negative impacts on already endangered warblers or vireos…which have mostly suffered from habitat loss as an initial cause of decline.
As for me, I’m fine with having one pair around every year. As long as things are balanced and healthy in the backyard, there’s no reason to fret about things…the birds will figure it all out just fine on their own.
Here’s more fascinating information on the Brown Headed Cowbird.