• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Western Grebe - BirdForum Opus

Revision as of 19:38, 27 April 2023 by KeithDickinson-10828 (talk | contribs) (→‎External Links: updated VSearch and GSearch)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Aechmophorus occidentalis
Photo by mrcolin2u
San Elijio,San Diego, USA, November 2006

Identification

A large and slender, long-necked North American grebe
Adult Breeding

  • Blackish-brown above
  • Mottled flanks and white below
    • Looks black and white from a distance
Juvenile
Photo by Leslie
Lake Cachuma, California, October 2005
  • Hindneck and crown blackish-brown
  • Dark of crown reaches below eye level
  • Red iris
  • Bill dark with yellow-green sides
  • Yellowish-grey legs

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.

Similar Species

Only likely to be confused with the closely related Clark's Grebe.

Extent of black on face and bill colour are the best features distinguishing this species from Clark's Grebe.

Distribution

Map-Western Grebe.png
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.
Legend

 A. o. occidentalis; year-round
 A. o. occidentalis; breeding
 A. o. occidentalis; migrating
 A. o. occidentalis; wintering
 A. o. ephemeralis; year-round
Maps/Texts consulted1,2,3,4

Vagrancy

Vagrants recorded in the Aleutians and on the Atlantic coast of the USA.

Taxonomy

Subspecies

There are 2 subspecies5:

  • A. o. occidentalis:
  • A. o. ephemeralis:
  • Western Mexico; not always recognized

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

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.

Vocalisation

Loud and harsh two-note kreek-kreek

References

  1. Sibley, David A. 2000. The Sibley Guide to Birds. New York: Alfred A. Knopf. ISBN 9780679451228
  2. Storer, R. W. and G. L. Nuechterlein. 1992. Western Grebe (Aechmophorus occidentalis). The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/026a.
  3. Brinkley, Edward S. 2007. Field Guide to Birds of North America. New York: Sterling Publishing Co., Inc. ISBN 9781402738746
  4. Howell, Steve N.G. and Sophie Webb. 1995. A Guide to the Birds of Mexico and Northern Central America. New York: Oxford University Press. ISBN 9780198540120
  5. Clements, J. F., T. S. Schulenberg, M. J. Iliff, B.L. Sullivan, C. L. Wood, and D. Roberson. 2012. The eBird/Clements Checklist of Birds of the World. 6th ed., with updates to October 2012. Ithaca: Cornell Univ. Press. ISBN 978-0801445019. Spreadsheet available at http://www.birds.cornell.edu/clementschecklist/downloadable-clements-checklist

Recommended Citation

External Links


GSearch checked for 2020 platform.1

Back
Top