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The surf scoter (''Melanitta perspicillata'') is a large sea duck, which breeds in Canada and Alaska. It is placed in the subgenus ''Melanitta'', along with the velvet and white-winged scoters, distinct from the subgenus ''Oidemia'', black and common scoters. It winters farther south in temperate zones, on the coasts of the northern United States. Small numbers regularly winter in western Europe as far south as the British Isles. Some birds may over-winter on the Great Lakes. It forms large flocks on suitable coastal waters. These are tightly packed, and the birds tend to take off together. The lined nest is built on the ground close to the sea, lakes or rivers, in woodland or tundra. 5–9 eggs are laid. An egg may range from and average in breadth and in length. Occasional (and likely accidental) brood mixing between different females occurs in areas with high densities of nests. Growth is relatively rapid and the incubation period is about 28 to 30 days. The offspring will fledge independently at about 55 days. The adult female averages about and in length, while the adult male is on average and in length, making this the smallest species of scoter on average. It is characterised by its bulky shape and large bill. The male is all black, except for white patches on the nape and forehead. It has a bulbous red, yellow and white bill. The females are brown birds with pale head patches. The wedge-shaped head and lack of white in the wings helps to distinguish female surf scoters from female velvet scoters. Adult scoters of this species dive for crustaceans and molluscs, while the ducklings live off any variety of freshwater invertebrates. In November, 2007, an oil spill in San Francisco harbour oiled and killed thousands of birds including many surf scoters. About 40% of the birds affected were from this species. Scientists said that while the species is not endangered it has declined 50 to 70% over the past 40 years and this spill could decrease populations since most of the affected birds are healthy adults.〔San Fran oil spill hurts Canadian sea duck population. CBC News. November 23, 2007. ()〕 ==References== ==External links== *(Photo of Surf Scoters wintering on the Salish Sea (British Columbia, Canada) ) * (Surf Scoter Species Account ) - Cornell Lab of Ornithology * (Surf Scoter - ''Melanitta perspicillata'' ) - USGS Patuxent Bird Identification InfoCenter * * 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「surf scoter」の詳細全文を読む スポンサード リンク
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