Breeding. Buffleheads are monogamous, and the females may return to the same nest site, year after year. ... There was one recorded instance of a female Barrow's goldeneye killing a bufflehead adult female and her brood. Smaller cavities are preferred because of less competition with the larger goldeneyes.

Where do buffleheads sleep?

Nest Placement

They usually choose cavities in poplar or aspen trees, except in California where they often use pine trees.

Are buffleheads monogamous?

Unlike most ducks, buffleheads are monogamous and stay with the same mate for several years. Females lay an average of nine eggs per clutch, primarily using nests constructed by other species. These nests are typically hollowed out cavities in trees and are close to a body of water.