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''Aechmophorus''〔Etymology: ''Aechmophorus'', "spear-bearer", from Ancient Greek ''aichme'' (a spear) + ''phoros'' (one who bears something around), in reference to its bill.〕 is a genus of birds in the grebe family. It has two living representatives breeding in western North America. *Western grebe, ''Aechmophorus occidentalis'' *Clark's grebe, ''Aechmophorus clarkii'' One prehistoric species has been described from fossil remains: *''Aechmophorus elasson'' (Late Pliocene of W USA) Although the two living species look very similar, bill shape and coloration, as well as feathering around the scarlet eye of the bird can be used to determine the precise species. ==Distinguishing features== The western grebe has a straight bill with a dull green-yellow color as opposed to the Clark’s grebe, which has a slightly upturned, bright orange-yellow bill. In both species the male has a longer and deeper bill than that of the female, making it a distinguishing feature.〔 All species of grebes display the pattern of lobed feet. A tough skin surrounds each toe separately, providing more surface area for effective swimming. This form increases the power of propulsion per stroke and reduces drag when the bird is recovering.〔 Skeletal measurements taken from both species, when averaged together, revealed that for the most part the western grebe is larger than the Clark’s grebe.〔 The two species also differ in their advertising calls. The western grebe gives a call that includes two distinct “cree-cree” notes, while the Clark’s grebe consists of a single “creeet” note, more drawn out.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Aechmophorus」の詳細全文を読む スポンサード リンク
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