© Copyright: Images: Jari Peltomäki, Kari Pihlaviita, Jouko Lehmuskallio, Simo Mikkonen. Recording: Jan-Erik Bruun. All rights reserved.
- Name also: Common Merganser
- Family: Waterfowl – Anatidae
- Appearance: A large duck. Males appear black and white, but females are grey with a brown head that has a crest. Female most easily distinguished from the similar Red-breasted Merganser female by thick base to bill and distinct edge to brown head colouring.
- Size: Length 58–68 cm, wingspan 78–94 cm, weight 1.3–1.9 kg.
- Nest: Nests in holes in trees, nest boxes, on or beneath buildings, or beneath dense juniper foliage.
- Breeding: 8–12 eggs laid April–May, incubated by female for 34–35 days. Ducklings leave the nest soon after hatching and quickly learn to find food for themselves, though they stay together with their mother as a brood until they learn to fly at the age of about 2 months. Some females forcefully adopt ducklings from other females, establishing large nursery broods.
- Distribution: Breeds by large, nutrient-poor waters throughout Finland. Finnish breeding population estimated at 20,000–30,000 pairs. During moulting may gather in large flocks numbering thousands of birds.
- Migration: By day. Leaves Finland September–December, returning (February–)March–April. Winters in the Baltic Sea and the North Sea, also around the Åland Islands and in other ice-free waters off Southern Finland.
- Diet: Fish, crustaceans, aquatic insects, tadpoles.
- Calls: A nasal series of “rok-rok…” calls.
- Endangerment: Vulnerable, protected. May be hunted in Finland during the duck hunting season. Globally Least concern.
Goosanders are diving ducks. Male Goosanders in breeding plumage appear white and black. Their heads are black with a green sheen, their backs and wingtips are blackish, and other parts of their plumage are white, though in spring their chests and bellies have an attractive pinkish tinge. Females have brown heads with a dense crest, grey upper parts and greyish white underparts. The borderline between their brown heads and whiter lower necks is distinct (blurred on female Red-breasted Merganser). The rectangular white patches on the trailing edges of their wings lack the dark central stripe present on the wing panels of Red-breasted Mergansers. Goosanders have red legs and bills. Their irises are red (male) or brown (female).