Susan Kirby

Brown-headed cowbirds (Molothrus ater) are opportunistic blackbirds who lay up to three dozen eggs each summer — in other birds’ nests. The foster parents will raise the cowbird young, often at the expense of their own offspring. It is an efficient system, if you’re a cowbird. There will be a video at some point. For now, a photo taken at the feeders in Central Park’s Ramble.