Western Grebe (aechmophorus occidentalis)

Western Grebe

[order] PODICIPEDIFORMES | [family] Podicipedidae | [latin] aechmophorus occidentalis | [UK] Western Grebe | [FR] Grebe elegant | [DE] Renntaucher | [ES] Achichilique Occidental | [NL] Zwanehalsfuut

Subspecies

Genus Species subspecies Breeding Range Breeding Range 2 Non Breeding Range
Aechmophorus occidentalis NA, MA w
Aechmophorus occidentalis ephemeralis w Mexico
Aechmophorus occidentalis occidentalis se Alaska and w Canada to nc USA Pacific coast to n Mexico

Physical charateristics

A large, slate and white grebe with a long, swanlike neck. Bill very long and thin, greenish yellow with a dark ridge. Downy young gray, without stripes.

Listen to the sound of Western Grebe

[audio:http://www.aviflevoland.nl/sounddb/W/Western Grebe.mp3]

Copyright remark: Most sounds derived from xeno-canto

wingspan min.: 79 cm wingspan max.: 86 cm
size min.: 55 cm size max.: 75 cm
incubation min.: 23 days incubation max.: 25 days
fledging min.: 63 days fledging max.: 75 days
broods: 1   eggs min.: 2  
      eggs max.: 5  

Range

North America, Middle America : West

Habitat

Rushy lakes, sloughs; in winter, bays, ocean. Summer: Mainly on freshwater lakes with large areas of both open water and marsh vegetation; rarely on tidal marshes. Winter:
Mainly on sheltered bays or estuaries on coast, also on large freshwater lakes, rarely on rivers.

Reproduction

Breeds in colonies. Courtship displays elaborate and complex. Include 2 (or more) birds rushing across surface of water in upright posture with loud pattering of feet, diving underwater at end of rush; “dancing” on water with bits of weed held in bill.

Nest: Site in shallow marsh. Nest (built by both sexes) a floating heap of plant material, anchored to standing vegetation.
Eggs: 2-4, rarely 1-6. Pale bluish white, becoming nest-stained brown. Incubation by both sexes, about 24 days. Hatching not synchronized; last egg may be abandoned in nest.
Young:
Climb onto back of parent within minutes after hatching, soon leave nest; are fed by both parents. Patch of yellow skin on head of young turns scarlet when young beg for food or are separated from parents. Age at first flight about 10 weeks. 1 brood per
year.

Feeding habits

Mostly fish. Apparently feeds mainly on fish at all seasons and in all habitats. Also known to eat crustaceans, insects, polychaete worms, salamanders. Like other grebes, also eats feathers.
Behavior: Forages by diving from surface and swimming underwater, propelled mainly by feet. Western an
d Clark’s are only grebes having structure in neck allowing rapid spearlike thrusting of bill; may be useful in spearing fish, but use of this behavior not well known.

Conservation

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Western North America. Winters to Mexico.
Western Grebe status Least Concern

Migration

Migrates at night, probably in flocks. Most birds from northern part of range migrate west to Pacific Coast. Some southwestern and Mexican populations probably permanent residents.

Distribution map

Western Grebe distribution range map

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