I have viewed and admired the Brown-headed Cowbird for years. I recently was able to capture this male cowbird in a photo as he foraged on the ground in back of my house. On the ground is where you will find the cowbird feeding, looking for weed/grass seeds along with insects, especially grasshoppers and beetles. A member of the blackbird family, the brown-headed cowbird is relatively small at 7 ½ inches long, with the males having a glossy metallic green-black body and a dark brown head. Females are a dull gray-brown overall. Note also the short, conical bill (along with the pointed wings) which helps to distinguish the cowbird from larger blackbirds.
After some study on this bird, I came to realize some interesting facts and habits that characterize the cowbird. For example, Male cowbirds court females with a variety of songs, bows, and sky-pointing displays. When the female is ready to lay an egg, she finds a nest that often already contains the eggs of the nest’s “owner.” This habit of laying its eggs in the nests of other birds makes the Brown-headed Cowbird a nest parasite. Cowbirds learned this behavior over centuries of following roaming herds of buffalo. The buffalo stirred up insects, the cowbird’s main food. But all the movement made it impossible to stop, build a nest, and wait for the young to grow. So the cowbirds did the most convenient thing, laid their eggs in any nest they could find along the way.
The “host” nest is most frequently that of a smaller songbird – yellow warblers, song sparrows, red-eyed vireos, and chipping sparrows seem to be frequent victims. The female cowbird may even remove one of the host’s eggs before depositing her own. Hatchling cowbirds are almost always larger than their nest mates and are able to out-compete them for food, which enhances the cowbirds chances of survival. Another interesting factoid is that some of the “host nest” bird species have evolved to recognize cowbird eggs and will build a new nest on top of the old one or will remove the cowbird egg.
Normally, I would add some tips on how to attract the particular bird I am writing about. However, in the case of the Brown-headed Cowbird I must mention a tip to limit their impact on our beloved songbirds. One way to discourage cowbirds is to stop offering mixed seed and cracked corn during spring when they show up at bird feeders before many migratory songbirds return. It’s a double-edged sword with regards to feeders….so make sure to be mindful of the timing of when you put out your seed in springtime…and be on the lookout for the Brown-headed Cowbird – Nest Parasite. Another Tip: Placement of your feeder can be helpful. Use your favorite internet search engine to look for ‘window bird feeders with strong suction cups’. They provide hours of entertainment, especially when positioned at an upper story window with inside access.