Individuals breeding elsewhere in California apparently nonmigratory, or at least the species is present year-round. Usually monogamous, but sometimes female changes mates during a single nesting cycle, and a tendency toward promiscuity in high density nesting. Often nests solitarily, but a tendency toward colonial breeding, especially on islands. Precocial young usually tended by hen only, but a drake may accompany for a few days. First fly at about 48-52 days, and become independent at that time, or earlier.
Agricultural practices destroy many nests, and heavy grazing destroys nesting cover.
Ducks, geese, and swans of North America. Stackpole Books, Harrisburg, PA. 544pp. Cogswell, H. L. 1977. Water birds of California. California Press, Berkeley.