Common scoter (Melanitta nigra)
|Also known as:||black scoter|
|Synonyms:||Anas nigra, Melanitta nigra nigra|
|Size||Length: 44 - 54 cm (2) (3)|
Male weight: 964 - 1,339 g (2)
Female weight: 973 - 1,233 g (2)
- The common scoter is a dark-coloured sea duck, often seen in large flocks at sea.
- The scientific name of the common scoter, nigra, means ‘black’, and refers to the male’s glossy black plumage.
- Until recently there were thought to be two subspecies of common scoter, but these are now classified as separate species.
- The common scoter feeds mainly on invertebrates such as mussels, which it dives underwater for and swallows whole.
The common scoter is classified as Least Concern (LC) on the IUCN Red List (1).
The common scoter (Melanitta nigra) is a medium-sized, rather stocky sea duck with a relatively long, pointed tail (3) (4) which is often held up when the bird is sitting on water (3). Until recently, this species was thought to include two subspecies, the common scoter (Melanitta nigra nigra) and the black or American scoter (Melanitta nigra americana) (2) (3) (5). However, the black scoter is now classified as a separate species (5) (6).
The scientific name of the common scoter, nigra, comes from the Latin for ‘black’, and refers to the entirely glossy black plumage of the male. The beak of the male common scoter is also black, with a swollen black knob at the base and a conspicuous patch of yellow on the top (2) (3) (4). In flight, the slightly paler undersides of the flight feathers contrast with the otherwise dark wings (3). In summer, the male common scoter becomes slightly duller and more mottled in appearance (2) (3) (4).
In contrast to the male, the female common scoter is dark brown, with a darker crown which contrasts with the pale sides of the head and neck (2) (3) (4). The female common scoter has a dark brownish to black beak and is also slightly smaller than the male (3). Juvenile common scoters are similar in appearance to the adult female (4), but are slightly browner and have some whitish bars on the belly (3).
The legs and feet of the common scoter are blackish- or olive-grey in the male, with black webbing, and a slightly lighter olive-brown to black or grey in the female. The eyes of this species are brown (2) (3).
The common scoter is generally a quiet bird, but during courtship the male may give a high, piping whistle (2) (3), described as a short ‘pju’ or ‘pjut’ (7). Female common scoters occasionally give a harsh, rasping call (2) (3).
Although the common scoter is similar in appearance to the black scoter (Melanitta americana), the male black scoter can be distinguished by its largely orange-yellow beak (2) (3), and by differences in its courtship call (7).
The common scoter breeds across northern Europe and northern Russia, including Iceland, Greenland, Scandinavia and the northern United Kingdom (2) (3) (5), and as far east as the Olenek River in Siberia (2) (3).
Outside of the breeding season, the common scoter moves south to spend the winter along inshore coastal waters of western Europe and western North Africa (3) (4), from Norway south to Mauretania (2) (3) (5). A large proportion of the common scoter population overwinters in the Baltic Sea (5) (6) (8).
This species occasionally occurs in central Europe and the Black and Caspian Seas on its migration, and vagrant common scoters have also been recorded in the Azores, the Canary Islands, Libya and the eastern Mediterranean (3) (5). A few common scoters spend the winter in ice-free waters near their breeding grounds (4), and some non-breeding individuals remain in the wintering grounds over summer (3) (4) (5).
The common scoter breeds around freshwater lakes, pools, rivers and streams in tundra and in open habitats in sub-Arctic areas (2) (3) (5). This species has a preference for breeding areas with suitable nesting cover (2) (5), but tends to avoid wetlands that are enclosed by forest (5).
Although it may sometimes use inland, freshwater lakes during its migration, the common scoter mainly overwinters at sea, where it is typically found in shallow, inshore waters and in bays and estuary mouths (3) (5).
The diet of the common scoter consists mainly of molluscs, particularly mussels. However, this species will also eat other invertebrates, such as shrimps, worms and insects, as well as small fish, fish eggs, and some plant matter (4) (5) (9). The common scoter usually catches its prey by diving underwater for it (3) (4) (9), and it swallows mussels whole, crushing their shells in its gizzard (9). This sea duck species typically dives with a short forward jump, with its wings closed tightly to its body (2) (3).
The common scoter is a highly sociable species and is often seen in large flocks, particularly during the winter. After breeding, male common scoters may travel some distance to gather in large flocks in coastal waters and moult, during which time they are flightless (2) (3) (4) (5).
Common scoters arrive on their breeding grounds in April and May, and breed from late May onwards (3) (5). The nest is built in a scrape on the ground, usually near to water and hidden in vegetation (3) (4) (5), and is lined with grass, moss and down (4). The female common scoter alone incubates the clutch of 6 to 8 eggs, which hatch after about 30 days (4).
The common scoter ducklings are dark brown with paler grey cheeks (2), and are able to swim and to feed themselves soon after hatching, although they are not able to fly until they are about 45 days old (4). The female and juvenile common scoters leave the breeding grounds to migrate to wintering areas in September, the males having already left to undergo their moult (3) (5).
Although the common scoter is widespread and not currently considered to be threatened with extinction (5), worrying declines in its populations have been recorded in recent years. For example, the number of common scoters overwintering in the most important wintering ground, the Baltic Sea, has fallen by around 47 percent in recent decades. This may have significant implications for the common scoter’s global population, although it is not yet known whether the decline is due to lower breeding success or to the birds shifting their winter distribution in response to climate change (6) (8) (10).
The breeding population in the United Kingdom has also declined (4) (11), and the common scoter is now a ‘Red List’ species there, meaning it is one which needs urgent conservation action (11) (12).
Although the exact reasons for these declines are unclear, the common scoter is thought to be under threat from oil spills, offshore wind farms, disturbance by boat traffic, hunting, and the commercial exploitation of its prey (2) (4) (5). Climate change, pollution and development could also potentially alter the ecosystems on which the common scoter depends (5) (8) (9). The common scoter may sometimes be caught accidentally in fishing nets (8), and might also potentially be under threat from introduced predators such as American mink (Mustela vison) (9), or from competition with introduced species such as trout (12).
The common scoter is listed as a ‘UK Priority Species’ for conservation, and is also protected under a range of national and international legislation (13). Conservation measures to protect its inshore marine habitats are not believed to be sufficient at present (2), and more needs to be done to reduce bycatch in fisheries, to re-route boat traffic, and to regulate hunting of this and other sea ducks (9).
Fortunately, a number of organisations are working to identify the causes of the common scoter’s decline and to look for solutions. Surveys are also underway to get a better understanding of where common scoters spend the winter months (12).
More research is needed into the potential effects of climate change on this species and its prey (9), and more detailed population information will be required to allow a proper assessment of the common scoter’s global conservation status (6). If the decline noted in the Baltic Sea is reflected in other common scoter populations, it is likely that this species will need to be re-classified as Vulnerable (VU) on the IUCN Red List (5) (8).
Find out more about the common scoter and its conservation:
BirdLife International - Common scoter:
RSPB - Common scoter:
Wildfowl & Wetlands Trust (WWT) - Common scoter:
More information on the conservation of sea ducks:
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- Bycatch: in the fishing industry, the part of the catch made up of non-target species.
- Flight feathers: the feathers at the end of the wing, involved in flight.
- Gizzard: in birds, a thick-walled muscular chamber in which tough food is ground up, sometimes with the aid of ingested pebbles or grit.
- Incubate: to keep eggs warm so that development is possible.
- Invertebrates: animals with no backbone, such as insects, crustaceans, worms, molluscs, spiders, cnidarians (jellyfish, corals, sea anemones) and echinoderms.
- Molluscs: a diverse group of invertebrates, mainly marine, that have one or all of the following; a horny, toothed ribbon in the mouth (the radula), a shell covering the upper surface of the body, and a mantle or mantle cavity with a type of gill. Includes snails, slugs, shellfish, octopuses and squid.
- Moult: periodic shedding of (usually) the outermost body covering (such as feathers, fur or skin) during growth and development, or at specific times of the year.
- Subspecies: a population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.
- Tundra: treeless, grassy plains characteristic of arctic and sub-arctic regions. They are very cold and have little rainfall.
- Vagrant: an individual found outside the normal range of the species.
IUCN Red List (May, 2013)
- Kear, J. (2005) Ducks, Geese and Swans. Volume 2: Species Accounts (Cairina to Mergus). Oxford University Press, Oxford.
- Madge, S. and Burn, H. (2010) Wildfowl. Christopher Helm Publishers, London.
- Holden, P. and Cleeves, T. (2010) RSPB Handbook of British Birds. Third Edition. Christopher Helm Publishers, London.
BirdLife International - Common scoter (May, 2013)
BirdLife International (2011) Taxonomic changes in the genus Melanitta, part 1: suggestion to list M. nigra as Vulnerable and request for information on M. americana. BirdLife International Globally Threatened Bird Forums, 29 November. Available at:
- Sangster, G. (2009) Acoustic differences between the scoters Melanitta nigra nigra and M. n. americana. The Wilson Journal of Ornithology, 121(4): 696-702.
BirdLife Europe (2011) Baltic seaduck take a dive. BirdLife Community, 1 December. Available at:
Bellebaum, J., Larsson, K. and Kube, J. (2012) Research on Sea Ducks in the Baltic Sea. Gotland University, Visby, Sweden. Available at:
Skov, H. et al. (2011) Waterbird Populations and Pressures in the Baltic Sea. Nordic Council of Ministers, Copenhagen. Available at:
RSPB - Common scoter (May, 2013)
Wildfowl & Wetlands Trust (WWT) - Common scoter (May, 2013)
JNCC: UK Priority Species - Melanitta nigra (May, 2013)