Mergus merganser



This elegant diving duck is bigger than the Mallard; it swims high in the water with a majestic posture, head held high. Its long, narrow bill has mandibles with serrated edges (sawbill), and is red and hook-tipped. Its head is proportionately large, its body is long and its neck is thick. The male's plumage appears white, but close-up he is touched with a light pink. His head is a deep green and his back is black. The female has a reddish bill, though not quite as bright as the male. Her body is grey and her head is orange-brown, darker in comparison to the Red-breasted Merganser female. She has a drooping, shaggy crest, a bright white throat and chin, brown neck and grey breast. Juvenile birds look like a duller female. When flying, both sexes have white wing patches, though the female's patches are only on the trailing edge of her wings, while the whole upper surface of the male's wings appear white in flight.


Primarily found in freshwater environments, this bird breeds in Scotland, northern England, Wales and a few farther south. It prefers upland and hilly areas with lakes and slow-flowing rivers, often close to wood or forests. When not in breeding season, they frequent freshwater lakes, old gravel workings and reservoirs.


This bird dives frequently and regularly dips its head below the water's surface in search of food. It is most often found in small groups, though larger flocks may form in the winter. Its long body extends in flight, and it has a habit of flying low, close to water. A group of these birds can fish as a team by swimming in a line and directing the fish forwards.


Fish, including young salmon, young trout and eels are most commonly eaten. Diet also includes small mammals and insects; Goosander ducklings feed on insects.


Pairs form in winter; males are sometimes seen bowing and stretching when courting. Nesting sites include holes in trees, stumps, crevices or beneath buildings. The female incubates 8-11 eggs alone for 30-32 days. The hatchlings leave the nest after a day or two; they feed themselves, and some ride on the backs of their mothers. After 65 days juveniles are independent.


Some males undertake a moult migration to Norway, but apart from that, most British breeding Goosanders live year-round in Britain. Some birds from north-east Europe and Russia migrate to the region around November or December for the winter, then return north in March. There are approximately 2 600 pairs breeding in the UK and up to 50 in Ireland; these numbers grow to over 16 000 with the winter visitors.

Observation Tips

In the spring, wooded and unspoilt upland river environments (in the Goosander regions) are the best places to look for these birds. They're rarely in large groups, so its best to watch for individuals, pairs and small groups.


Predominately a silent bird, the male may make gentle ringing calls when displaying, or a low growl if disturbed.