Brown headed cowbirds (Molothrus ater) are called brood parasites, birds that lay eggs in other birds’ nests. It’s said that up to 150 different species in North America are parasitized by cowbirds and the host parents then raise the young. Needless to say, cowbirds are generally looked upon with loathing. Whenever I see this species near our bluebird house, I am out the door clapping and shooing the scourges away.
That is until a fledgling cowbird nearly landed in my lap a few days ago. It had been reared by a tiny chipping sparrow and now it seemed abandoned. I watched as it chased every chipping sparrow it saw, more than a dozen around the feeder at a given time. All flew away or scurried to hide when this big baby ran at them, mouth open, flapping wings, and warbling like a baby chipping sparrow.
After watching it beg for a day with no food, I broke down and fed it a few mealworms.
And now the fledgling flies to me several times a day! That makes me wonder how the heck it can learn to be a cowbird. It is still excited to see a chipping sparrow but absolutely thrilled when it sees me open the door. Hey, you are a cowbird, little guy!
I’ve seen cowbirds walking in the grass nearby but our fella doesn’t seem at all interested. With a Google search, I found Matthew Louder, an ecologist, who states in Animal Behavior journal that the juvenile cowbirds leave the host’s territory at sunset, perhaps encountering adult cowbirds in wooded areas, returning to their hosts in the morning, thus fostering independence.
But it doesn’t explain how juveniles locate and recognize their own kind. Does our little fledgling fly to the woods when the sun sets to meet up with other cowbirds? We don’t know. But, each day it is standing at the door when we rise at 6 a.m.
Fly away soon, little cowbird. Fly far, far, far, far away and never come back to lay an egg in our bluebird box!