Goosander

Latin Mergus merganser L.
Estonian Jääkoskel

Also known as: common merganser

Status in Estonia

Breeding, migratory and wintering bird.

Description

The goosander is an Anatidae with a long, sleek body and a long, thin beak. The male bird’s nuptial plumage is mostly white; the head and top of the neck are black with a green sheen; the front, back and inner shoulder feathers are just as black; and the crown is somewhat rounded, giving the nape a characteristic humped appearance. A large white spot on the secondaries is visible in flight. The female bird’s head is dark reddish-brown and its crown is more pointed than that of the male bird, with two tufts on the head, one on the back of the crown and the other on the back of the head. The male bird in eclipse plumage looks similar to the female, but the upper half of the wings is mostly white. Juveniles resemble female birds, but the beak is a less vibrant red, the tuft is shorter, the chin patch is not completely white and the lore and iris are light.

Size

Body length 58–68 cm, wingspan 78–94 cm, body mass 1.3–1.9 kg.

Similar species

Red-breasted merganser.

Distribution

The goosander inhabits the northern part of Eurasia. In Central Europe, the area stretches into the temperate zone but does not generally extend south of 50 degrees latitude. A separate breeding region is located in the Alps, while a few dozen birds breed in the Balkans. In North America and the highlands of Asia, other subspecies replace our nominate species. In Estonia, it inhabits rocky capes, small islands, rivers and lakes.

Population

Estonia has 2000–3000 breeding pairs.

Occurrence in Estonia

It arrives here during March. The migration of northern birds begins in September, and the majority of the goosanders leave by mid-November. A significant amount (5000–22,000) of goosanders remain in our waters to winter.

Diet

It hunts fish and can dive to depths of up to 4 metres when hunting.

Habitat

It inhabits rocky sea capes, small islands, rivers and lakes in Estonia. It is particularly common around coastlines, both on the mainland and on islands. It is spread out over several tens of kilometres near the water, rather than concentrated along the coast.

 Nesting

Nests can be found in natural hollows in tree trunks many metres above ground, under tree roots, or in a cave eroded by water by the shore. Nests on sea islands can be found in piles of stones, sometimes in inaccessible locations, but nests can also be found under a washed up fish box or in a mountain currant bush. Corners of hay barns, granaries, holes beneath foundations and boathouses and nest boxes are also common places to nest.
From April to May, the female bird lays 10–15 creamy white elongated eggs. Sometimes numerous female birds lay eggs in the same nest, resulting in more than 40 eggs that no one hatches. The chicks hatch at the end of May through June. The chicks need to jump from the nest to the ground when they’re two days old; when they reach the water after following their mother, they can also ride on her back for a short time. Chicks frequently gather in nurseries, which are made up of multiple broods and cared for by a single female bird. The female bird may depart after 60–70 days, which is before the chicks are able to fly. Male birds gather in big flocks at the start of June and migrate to moult near sea islands.

Conservation status and protection

Not under protection. The most serious threats are water contamination and disruptions to breeding and migration stopovers. It is a gamebird.

Distribution and population in Lääne County

The goosander is a common migratory, wintering and breeding bird in Lääne County. Goosanders make frequent migratory stops in Matsalu and Haapsalu bays in the early spring and late autumn. They are typically the earliest waterfowl to gather in open water areas and the last to go when the bays freeze. It is good to observe goosanders that take a break during their migration in Puise or Keemu. In the autumn months, between October and November, hundreds of goosanders gather in Tagalaht Bay in Haapsalu. Wintering goosanders are more common at Cape Põõsaspea and Port of Dirhami.

Nesting boxes for goosanders have been placed around many parts of Lääne County. Every year, a few pairs of goosanders build their nests in the ruins of Haapsalu Castle. Goosanders also nest under larger rocks on sea islands.