The family Podicipedidae includes 7 species found in North America.
Grebes are small to medium-sized (23-76 cm in length; 150-1500 gms weight) foot-propelled divers with thick, soft, waterproof plumage. Small, narrow wings and legs set far back. Food is mainly aquatic animals usually captured by diving, searching and pursuing prey underwater. Fish-eating species have elongate bodies and long necks and bills. Species that eat mainly invertebrates tend to be rotund and to have short necks and bills. Fish-eaters swallow their own feathers and also feed them to their young, possibly to entangle fish bones in the stomach. Pellets composed of bones and feathers are regurgitated. Pellet formation and regurgitation also occur in grebes that eat insects and crustacea.
Nests are shallow heaps of aquatic plant stems and leaves usually concealed in aquatic vegetation, floating, anchored to plants or on a platform built up from the bottom. Nests are rarely on land near water. Most species are territorial and some breed in colonies. Clutch 2-7 elongate eggs, white or cream-colored when laid, soon stained brown. Incubation is 20-28 days beginning with the first or second egg, by both sexes. When the incubating adult is disturbed or is leaving the nest it covers the eggs with nest material. Young are precocial but depend on both parents for food, warmth and protection. They often ride on backs of parents when small.
Grebes - Patuxent Bird ID Center