This is the first time I have seen a Brown-headed Cowbird at my feeders, therefore I wanted to learn more about them.
The Brown-headed Cowbird has a fascinating approach to raising its young. Females forgo building nests and instead put all their energy into producing eggs, sometimes more than three dozen a summer. These they lay in the nests of other birds, abandoning their young to foster parents, usually at the expense of at least some of the host’s own chicks. Once a Cowbird locates the nest, she usually waits until the host has laid two or more eggs, but before incubation begins. She generally removes one egg or more the day she lays her egg in the nest, or sometimes before. She only lays one egg in a nest. Cowbirds have been known to lay eggs in the nests of some 220 other species. About 20% of these nests are of Eastern Phoebe, 25% of Carolina Wren, and 40% of Song Sparrow nests. Since they raised by other species, they do not learn how to behave like a Cowbird from their forest parents. It appears this information is genetic. Therefore, a Cowbird knows its own song and calls, and recognizes and mates with its own species, despite having never encountered another of its own kind before.
Although I am totally fascinated by these birds, I hope I don’t see them at my feeders again.
Today is Outdoor Wednesday. Please check out these other great blogs at A Southern Daydreamer.
