Comments: Marshes, lakes, and bays; in migration and winter also sheltered seacoasts, less frequently along rivers (Subtropical and Temperate zones) (AOU 1983). Nests on large inland bodies of water. Breeding ponds/lakes in North Dakota usually have 20 ha or more of open water. Nests usually in or very close to water deep enough to allow bird to swim submerged. Nests typically is anchored to, or build up over, living vegetation (Ehrlich et al. 1992).