Goosander

The goosander (Mergus merganser) is a diving duck of the sawbill family. Sawbills are so named because their long bills have serrated edges that are used for catching and holding on to fish.

Range and habitat

The goosander inhabits northern Europe and Asia, being either resident or migratory. It is closely related to the common merganser of North America, there being only minor differences between the two sub-species. 

In the British Isles the goosander is found in upland areas of Scotland, Wales and northern England, where it nests alongside rivers and lakes surrounded by woodland. In winter goosanders move to open lakes, reservoirs and estuaries, and this is the only time when they can be seen in southern England.

The goosander was first recorded as breeding in Scotland in 1871, and its spread into Wales and England has been relatively recent. It is now a well-established species, despite its liking for salmon and trout which brings it into conflict with anglers.

Appearance

The male goosander is about 70 centimetres (27.5 inches) in length, and the female about 60 centimetres (23.5 inches) long. The male has a largely white body, tinged underneath with pink or cream, with a black back and almost black (with a green sheen) head and neck. The outer wings are black and the rump and tail are grey. The bill is bright red.

Female goosanders have much greyer plumage, although the throat and belly are white. The head and neck are reddish brown with prominent nape feathers. The outer wings are black and the secondary feathers (i.e. the wings’ inner trailing edges) are white. The bill is dull red.

Behaviour

Male and female goosanders have different calls, with the male producing low-pitched croaking sounds in contrast to the harsh “karr” and cackle of the female.

Goosanders dive for fish and eels, either from the surface or from flight. They float quite high in the water. They are fast flyers, with their wings making a humming whistle as they go.

As well as the fish and eels mentioned above, goosanders will also feed on crustaceans, tadpoles and other small creatures.

Goosanders are gregarious, and have been known to form flocks of a thousand or more birds, although this is unlikely to happen in Britain, where overall numbers are not as great as in certain parts of continental Europe.

Breeding

A preferred nest-site for a goosander is a cavity in an old tree close to the water, and the nest can be 15 metres or more above the ground. If such a site is not available, nests can be built among rocks or in holes in river banks. If the nest is in the open, it will be lined with grass, leaves and moss.

The clutch, laid at any time between mid-March and May, will comprise anything from seven to twelve eggs, which are not incubated until the last one has been laid, thus ensuring that all the ducklings hatch at the same time. Incubation, by the female alone, takes about 30 days, after which the ducklings leave the nest of their own accord, sometimes falling from a considerable height straight into the water, where their mother joins them. Only one brood is raised in a season.

© John Welford