Why Is This Bird Feeding Goldfish?

A few years ago, a birdwatcher in rural Illinois noticed a cardinal behaving strangely in her garden. It seemed to be feeding her goldfish. As many as six times in a single day, the bird would return to the pond where the fish would greet it with open mouths.

The bird would apparently feed them seeds and other food, as if they were chicks in a nest. In fact, the fishes' mouths may have looked just enough like those of baby birds that a parental instinct kicked in.