Aechmophorus clarkii

Clark's grebe (Aechmophorus clarkii) is a North American waterbird species in the grebe family. Until the 1980s, it was thought to be a pale morph of the western grebe, which it resembles in size, range, and behavior. Intermediates between the two species are known. This species nests on large inland lakes in western North America and migrates to the Pacific coast over the winter. It maintains local populations year-round in California, Nevada, and Arizona (the Lower Colorado River Valley), as well as in central Mexico. It feeds by diving for insects, polychaete worms, crustaceans, and salamanders. It performs the same elaborate courtship display as the western grebe. The 'Clark' of its common name—and its specific epithet clarkii—honors John Henry Clark, a 19th-century American surveyor who was also a naturalist and collector. The genus name Aechmophorus comes from the Ancient Greek words αἰχμά (transliterated 'aichme'), meaning 'point of a spear', and φόρος ('phoros'), meaning 'bearing'; together translating as 'spear point bearer' and referring to the bird's long, dagger-like beak. In Mexico it is called achichilique pico naranja (the western grebe is called the achichilique pico amarillo). A common name advocated in Spain for this bird is the calque achichilique de Clark. Clark's grebe closely resembles the western grebe and occurs in the same colonies together with it. Storer and Nuechterlein in 1992, following earlier morphological studies by Storer and others, define the species as being distinguished from the western grebe by an overall paler plumage on its back, as well as a larger portion of its face covered in white, as it extends above the eyes, rather than just below them. A distinguishing feature is its bill, which is bright yellow in the US, whereas the Western Grebe's bill is greenish-yellow in the US, which had been noted by others. Storer and Nuechterlein in 1992 claim that the bill is slightly upturned in this species whereas the western grebe has a straight bill, this was not noted in earlier studies. The grebe has a long, slender neck and the species ranges in size from 22–29 inches (56–74 cm), with a wingspan of 24 inches (61 cm). There are few changes between the sexes, the most notable feature that distinguishes males from females is the presence of a slight crest on the heads of males. In juveniles, the plumage is again similar to the Western Grebe, however it is also paler compared to the greyer Western species.