The Brown-Headed Cowbird

By Terri Estes

I often find brown-headed cowbirds at my feeders. The males are easily recognizable. They have a glossy black plumage on their stocky body and wings and a rich brown head that can appear reddish in bright sunshine. The female is much less distinct looking as they are plain brown birds, with some streaking of darker brown on their bellies with their heads sometimes having a lighter color. Cowbirds are named for their tendency to follow herds of cattle and bison, which stir up insects on the ground as they graze. This makes meals easy to find for the birds. The name “cowbird” was first recorded in 1839. Before that, they were known as “bison birds” because they were often seen following bison herds across the Great Plains.

The cowbird can be found all across North America. They are short-distance migrators and will travel to the southern United States and Mexico for the winter. They have proven to be a very adaptable bird. As their preferred landscape of forests and fields have been reduced, they have become quite comfortable in urban and suburban areas.

Many people consider the brown headed cowbird to be a nuisance. Why would such a cute little bird be a nuisance? Well, this is a very clever bird. Cowbirds don’t make their own nests, and don’t raise their own young. Instead, the female cowbird watches other species prepare nests to raise their families. She sits and waits, and when the other birds have laid their eggs, she will go and deposit a single egg in that nest when it is briefly left unattended. They usually choose a nest of a bird smaller in size, so their egg will be larger than the host’s eggs. Cowbird eggs incubate in 11 to 12 days while most other breeds need 12 to 14 days of incubation time. This gives the cowbird baby a one- or two-day head start and allows them to monopolize food from their younger foster siblings. This often leads to starvation of at least one and sometimes all of the other babies. Some birds recognize the cowbird intruder egg and toss it out or puncture it, but most unsuspecting hosts don’t realize the difference and raise the cowbird baby as its own.

So, after reading about the parasitic behavior of the cowbird, I’ve definitely soured a little bit on my backyard visitor. I will say that it is genius, pure genius, to have no responsibility whatsoever for providing for your offspring and letting complete unsuspecting strangers carry the burden.