What about this bird's diet helps protect its offspring?


Many birds are parasitized by Cowbirds, who lay their eggs in other bird's nests. The young Cowbirds eat most of the food, and often wind up killing the bird's actual offspring.

The American Goldfinch feeds almost entirely on seeds and plant material. While this diet is great for baby Goldfinches, baby Cowbirds need a diet with insects to survive. If a Goldfinch nest is parasitized by Cowbirds, the young Cowbirds starve on a diet of only seeds, letting the baby Goldfinches survive.