Bird of the Month: Eared Grebe
By Andrew McCormick
Scientific Name: Podiceps nigricollis
Length 13 in
Wingspan 16 in
Weight 11 oz
AOU Band code EAGR
The Eared Grebe is the most abundant member of its family in both North America and the world. Gregarious by nature it breeds in large colonies in southwestern Canada and central and western United States. After breeding, grebes congregate at the highly saline Great Salt Lake and Mono Lake and feed on brine shrimp (Cullen, et al). In general it prefers invertebrates and small crustaceans to fish and most of the time it forages by deep dives lasting around 20-30 seconds.
The Eared Grebe shares the Podiceps genus with the Horned Grebe (P. auritus) and the larger Red-necked Grebe (P. grisigena). Podiceps is from the Latin podex, the anal orifice, and pes, foot, referring to the fact that when swimming its feet appear to be coming out of its rump. Nigricollis, black-necked, is from the Latin niger, black, and collum, neck (Holloway). The bird was once called the Black-necked Grebe (Pough). Grebe is the French name for this type of bird. Eared refers to the wispy golden plumes of the breeding plumage near where ears would be.
As an uncommon visitor to Washington marine waters in winter, the Eared Grebe can be missed because of its similarity to the Horned Grebe which is close in size, shape and coloration. In basic (nonbreeding) plumage the Eared Grebe has a grayer front of the neck and face, while the Horned Grebe has a white neck and face with the black crown sharply separated along a line extending straight back from the bill (Cullen, et al). The Eared Grebe has a steeper slope to its forehead with its head peaked above the eye.
In alternative (breeding) plumage the Eared Grebe has a black head and neck and yellow-orange fan-like feathers behind the eyes. Its eyes are red in all plumages except juveniles which have a yellowish eye. The bill is black and the neck and sides are chestnut. Like other grebes Eared Grebes have a complex courtship ritual that includes swimming side by side while calling loudly, facing each other and raising up chest to chest, and at the climax of the display rearing up and rushing across the water together (Kaufman).
Eared Grebes nest in large colonies on marshy lakes where both parents contribute to building a nest consisting of a floating platform of weeds. Three to five white eggs are incubated by both sexes for about three weeks. When the young can swim the adults may separate with each taking part of the brood. At times young grebes will ride on the back of an adult and remain there during underwater foraging. Their age at first flight is not well known (Kaufman).
In 1997 the population of Eared Grebes in North America was estimated at 4.1 Million individuals and the species is considered secure. Because they congregate in such large numbers they can be susceptible to large die-offs from food scarcity. The cause of a die-off estimated at 150,000 grebes at the Salton Sea in 1991 has not been explained.