Species: Aechmophorus occidentalis

Western Grebe
Species

    Eggs: in Oregon, mean length was 58.1 mm, mean width was 38.7 mm, and mean mass was 48.4 g (Hill et al. 1995, Condor 97:1062-1064).

    Science Review:

    Articles:

    Effects of season, location, species, and sex on body weight and blood chemistry in free-ranging grebes

    An article published in the Journal of Avian Medicine and Surgery in 2021 describes the results of study comparing the effects of season, location, species, and sex on body weight and blood chemistry for free-ranging western and Clark's grebes.

    Western grebe (Aechmophorus occidentalis). Photo: Ingrid Taylar (CC BY-NC 2.0) https://flic.kr/p/7jmJHZ
    Declines in marine birds trouble scientists

    Why did all the grebes leave? Where did they go? And what does their disappearance say about the health of the Salish Sea? Seasonal declines among some regional bird species could hold important clues to the overall health of the ecosystem.

    Western grebe. Public Pier, Blaine, WA. Photo: Andrew Reding https://www.flickr.com/photos/seaotter/10298390254
    Paper: Citizen science reveals an extensive shift in the winter distribution of migratory Western Grebes

    A June 19, 2013 paper in the journal PLoS ONE hypothesizes that regional declines in Western Grebe populations may be related to decreasing numbers of forage fish. Using citizen science data from 36 years of bird counts, researchers were able to look at population trends up and down the entire West Coast, finding that abundance of grebes decreased in the Salish Sea but increased in southern California. North American population declined by 52% overall.

    Western Grebe; image by mikebaird, courtesy of Encyclopedia of Life
    Western and Clark's Grebes (Aechmophorus occidentalis and A. clarkia)

    This article was originally published by the Washington Department of Fish and Wildlife as part of its annual report Threatened and Endangered Wildlife in Washington.

     

    Clark’s grebe, left, is similar to the western grebe, right, but has white around the eye and a brighter yellow bill (photos by Joe Higbee).
    Marine birds

    More than 70 bird species regularly utilize Puget Sound during some or all stages of their life histories, but only a portion of these are actively being investigated.

    Brandt's cormorant (Phalacrocorax penicillatus). Photo by Finley and Bohlman, courtesy U.S. Fish and Wildlife Service
    Kingdom
    Animalia
    Phylum
    Craniata
    Class

    Aves

    Order

    Podicipediformes

    Family

    Podicipedidae

    Genus

    Aechmophorus

    Classification
    Other Global Common Names
    Achichilique Pico Amarillo - grèbe élégant
    Informal Taxonomy
    <p>Animals, Vertebrates - Birds - Other Birds</p>
    Formal Taxonomy
    Animalia - Craniata - Aves - Podicipediformes - Podicipedidae - Aechmophorus - (Clark's grebe) (AOU 1985, 1998).

    Eggs: in Oregon, mean length was 58.1 mm, mean width was 38.7 mm, and mean mass was 48.4 g (Hill et al. 1995, Condor 97:1062-1064).

    Migration
    <p>false - true - true - Begins departure from southernmost coastal wintering areas late March or April, moves inland by late April-early May. Migration evidently nocturnal over land, partly diurnal along coast. Apparently migrates in flocks.</p>
    Non-migrant
    false
    Locally Migrant
    true
    Food Comments
    Diet mainly fishes; opportunistic as to species eaten. Also eats insects (adults and larvae, especially in spring and summer), mollusks, crabs, marine worms, and salamanders. Ingests feathers and small stones. (Terres 1980, Johnsgard 1987). Obtains food underwater after diving from surface.
    Reproduction Comments
    Reported average clutch size: about 2.5 in Utah, 3.4 in Colorado, 4.2 in North Dakota; dump nesting may result in large clutch in one nest. Incubation, by both adults in turn, lasts 3-4 weeks. Brood size usually is 1-3. Young are tended by both parents. Nests in colony; usually tens or hundreds of nests.
    Ecology Comments
    Gregarious.
    Length
    64
    Weight
    1477
    NatureServe Global Status Rank
    G5
    Global Status Last Reviewed
    1996-11-20
    Global Status Last Changed
    1996-11-20
    Conservation Status Map
    <img src="http://www.natureserve.org/explorer/servlet/GetMapGif?CA.AB=S3&CA.BC=S1&CA.MB=S4&CA.SK=S5&US.AK=__&US.AZ=S3&US.AR=__&US.CA=SNR&US.CO=S4&US.ID=S2&US.IL=__&US.IA=__&US.KS=S1&US.MN=SNR&US.MT=S4&US.NN=S3&US.NE=S3&US.NV=S4&US.NM=S3&US.ND=SNR&US.OK=__&US.OR=S3&US.SD=S4&US.TX=S3&US.UT=S4&US.WA=S3&US.WI=S1&US.WY=S4" alt="Conservation Status Map" style="width: 475px; height: auto;" />
    Global Range
    GH - 200,000 to >2,500,000 square km (about 80,000 to >1,000,000 square miles) - GH - BREEDS: south-central British Columbia, central Alberta, central Saskatchewan, and southwestern Manitoba, south to California, northern Utah, North Dakota, western Nebraska, northwestern Iowa, and western Minnesota; also locally in Mexico from Chihuahua and Durango south to Guerrero, Puebla, and San Luis Potosi. WINTERS: mainly along Pacific Coast from southeastern Alaska and British Columbia south to northwestern Mexico.
    Global Range Code
    GH
    Global Range Description
    200,000 to >2,500,000 square km (about 80,000 to >1,000,000 square miles)
    ELEMENT_GLOBAL.2.106135