American Dipper Overview, All About Birds, Cornell Lab of Ornithology

The American Dipper chooses a nest site, invariably along a stream, that provides security from floods and predators. Availability of suitable nest sites appears to limit its populations.

To be able to survive in cold waters during the winter, the American Dipper has a low metabolic rate, extra oxygen-carrying capacity in its blood, and a thick coat of feathers.

Unlike most other songbirds, but similarly to ducks, the American Dipper molts its wing and tail feathers all at once in the late summer. The bird is flightless during this time.