- Aechmophorus occidentalis
Description
Identification
A large and slender, long-necked North American grebe only likely to be confused with the closely related Clark's Grebe. Adult breeding: blackish-brown above with mottled flanks and white below, looking strikingly black and white from any distance. Hindneck and crown blackish-brown, dark of crown reaching below level of eye. Iris red, bill dark with yellow-green sides, legs yellowish-grey. Adult non-breeding and juvenile: similar but duller and with less clear-cut contrast between dark and light plumage. Flight: upperwing shows bold white bar but less extensive than that of Clark's. Extent of black on face and bill colour are the best features distinguishing this species from Clark's Grebe. Length 64cm. Wingspan 90cm.
Distribution & Taxonomy
Central Alberta to southern Manitoba and in the northern and western USA from Minnesota and South Dakota westwards and south to California and west Mexico. Only recently separated from Clark�s Grebe A. clarkii and the exact ranges of the two forms have yet to be elucidated. Resident in south-west of range but elsewhere a migrant. Wintering range extends from the southern coast of British Columbia south to west Mexico, in New Mexico and west Texas and on the Gulf Coast of Texas and Louisiana. Vagrants recorded in the Aleutians and on the Atlantic coast of the USA.
Subspecies: None usually recognised although Mexican birds are sometimes separated as ephemeralis.
Habitat :
Breeds colonially on large freshwater lakes, winters on large inland waters and sheltered sea coasts.
Behaviour
Voice: Loud and harsh two-note �kreek-kreek�.
Nesting:Breeding begins mid-May in south of range to early June in north. Breeds in large colonies, nest is a heap of vegetation anchored to emergent plants or on the bottom in shallower water. Eggs: 3-4, whitish with green or buff tinge initially, soon becoming stained (59 x 38mm). Incubated by both sexes for 23 days. Young tended by both sexes and leave nest on hatching.
Diet: Fish and aquatic invertebrates.
