Common Scoter

When at sea the common scoter feeds mainly on small fish and invertebrates. In the freshwater breeding habitat it also takes insect larvae, fish eggs and the seeds of water plants (6). They dive to obtain their food, (6) and whilst submerged the wings are partially opened in order to stabilise themselves as they search for food on the bottom (4). Scoters start to pair up in winter. The nest is built on the ground amongst dense vegetation from grass, moss lichens and down (6). Between 6 and 8 buff-coloured eggs are laid between the end of May and late June; shortly after this the male leaves the female and joins other males before going to sea to moult. Soon after hatching the young are able to swim but do not fledge for another 45-50 days (2).

More than half of the British breeding population of common scoters occurs within protected areas. Other sites are proposed Sites of Special Scientific Interest (SSSIs). An EU LIFE-Nature funded scheme to restore damaged peatlands, and the SNH Peatland Management Scheme operate in the breeding range of the common scoter; these should assist its conservation (3). Many conservation organisations have been lobbying for tighter restrictions on oil transportation around the coastline. The common scoter is a priority species under the UK biodiversity Action Plan. The Species Action Plan aims to increase the breeding population to 100 pairs by 2008 (3).

The name Melanitta comes derives from the Greek for 'black duck' (4). Males have glossy black plumage with a patch of orange on the black bill and females are dark brown. Both sexes have short tails that point upwards as they swim (2). Common scoters tend to fly close to the sea in long lines or in small groups, when they produce a whistling call. They are usually seen along coasts, sitting on the water, appearing and disappearing from view as they dive under the water (2).

Common scoters breed on freshwater. Nesting occurs around moorland (5) or peatland lochs (6). They over-winter at sea in shallow inshore waters (6).

The common scoter breeds in Fenno-Scandia, northern Russia, Iceland, Scotland and in north-west Ireland. Its wintering grounds are along Atlantic coasts down to north-west Africa and the Pacific coasts of the southern USA and China (5). A 1995 survey discovered that there were 89 breeding pairs in the UK, all of which were in Scotland (6). The UK wintering population is large and mainly found on inshore waters in Wales, eastern Scotland and north-east England; most of these birds breed in Sweden, Finland and Siberia (6). The wintering sites of the British breeding common scoters are not known. In late summer and autumn common scoters also form large moulting flocks in UK waters (3).

Listed on the Red List of Birds of Conservation Concern. Protected under Schedule 1 of the Wildlife and Countryside Act 1981, Annex II/2 of the EC Birds Directive and Appendix III of the Bern Convention (3).

In the last 25 years the UK breeding population of the common scoter has declined by over 50%, and it was completely lost from Northern Ireland by the early 1990s (3). There are thought to be a number of factors contributing to this decline. Wintering scoters are extremely vulnerable to oil spills; a single spill can affect very large numbers (6). Food availability is also an important factor (6), and increased competition for invertebrate food in breeding lakes may arise from increased fish stocking (3). As the breeding population is so low in the UK, predation can take a huge toll on the common scoter. Mink, foxes, otters, crows, magpies and even pike are all potential predators (5).