Black scoter

Black scoter
Adult male
Conservation status
Near Threatened(IUCN 3.1)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Anseriformes
Family:	Anatidae
Genus:	Melanitta
Subgenus:	Oidemia
Species:	M. americana
Binomial name
Melanitta americana (Swainson,1832)
Synonyms
Melanitta nigra americana

Theblack scoterorAmerican scoter(Melanitta americana) is a largesea duck,43 to 49 cm (17 to 19 in) in length. The genus name is derived fromAncient Greekmelas"black" andnetta"duck". The species name is from theLatinfor "American".

Together with thecommon scoterM. nigra,it forms the subgenusOidemia;the two are sometimes consideredconspecific,the black scoter then being referred to asM. nigra americana.Its French name, used in parts of itsCanadianrange, ismacreuse noire(also meaning "black scoter" ).The species is listed as Near Threatened by the IUCN.

Description

This large sea duck is characterised by its bulky shape and large bill. The adult male is all black with a very bulbous bill which is mostly yellow. The female is a brown bird with pale cheeks, very similar to female common scoter. The adult female averages about 980 g (2.16 lb) and 45 cm (18 in) in length, while the adult male is on average 1,100 g (2.4 lb) and 49 cm (19 in) in length.

This species can be distinguished from other scoters, apart from common scoter, by the lack of white anywhere on the drake, and the more extensive pale areas on the female.

Standard Measurements
length	430–550 mm (17–21.5 in)
weight	950 g (2.09 lb)
wingspan	710 mm (28 in)
wing	213–233 mm (8.4–9.2 in)
tail	83–97 mm (3.3–3.8 in)
culmen	42–45.5 mm (1.65–1.79 in)
tarsus	45–48.5 mm (1.77–1.91 in)

Vocalisations

The black scoter and common scoter have diagnosably distinct vocalisations.

Distribution and habitat

The black scoter breeds in the far north ofNorth AmericainLabradorandNewfoundlandto the southeast and northwest ofHudson Bay.It also occurs on theSiberianside of theBering Straitseast of theYana River.Itwintersfarther south intemperatezones, on the coasts of the northernUSAandCanada,on thePacificcoast south to theSan Francisco Bayregion and on theAtlanticandGulf of Mexicocoasts, and inAsiaas far south asChina.

Some birds may over-winter on theGreat Lakes.This species is a very rare vagrant to westernEurope;only drakes are safely identifiable out of range, so females are likely to be undetected.

Ecology

Female Black Scoter photographed inOttawa,Ontario

This species dives forcrustaceansandmolluscswhile migrating or wintering on the sea-coasts, and feeds oninsectsand their larvae, especiallycaddisflies,fisheggs and, more rarely, vegetation such asduck weedwhile nesting on freshwater. It forms large flocks on suitablecoastalwaters in winter quarters. These are tightly packed, and the birds tend to take off together; in the breeding season they are less social. It has been suggested that in coastal waters this species prefers sheltered embayments, and possibly waters that include some mixed depths.

Black scoters nest later than most other ducks in North America. Pairs form in late winter or spring. The lined nest is built on the ground close to the sea, lakes or rivers, in woodland ortundra.5–7eggsare laid. Each eggs weighs from 60–74 g (2.1–2.6 oz), or 8% of the females body weight. The incubation period may range from 27 to 31 days. Females brood their young extensively for about 3 weeks, after which the still flightless young must fend for themselves.

The male performs a diagnostic downward head movement when stretching his wings.

External links

• Black Scoter Species Account and Photo Gallery– Sea Duck Joint Venture
• "Black scoter media".Internet Bird Collection.
• Black scoter photo galleryat VIREO (Drexel University)
• Black Scoter Species Account– Cornell Lab of Ornithology
• Interactive range map ofMelanitta americanaatIUCN Red List maps