The Long-tailed Duck (Clangula hyemalis) is an Arctic sea duck whose male carries a long, pointed tail, forming winter flocks of thousands along the Baltic coasts. It is a strongly Arctic species, breeding around the tundra and mountain regions of the northern hemisphere in North America, Europe and Asia, and despite a large world population it has declined sharply and is classed by the IUCN as vulnerable. The male measures 40–47 cm, or up to 58 cm including its greatly elongated central tail feathers, with a wingspan of 73–79 cm and a weight of 650–900 grams. Its winter plumage is striking — a mostly white body with a black breast, a dark brownish-black cheek patch against the white head, and the long, pointed tail spikes — while in summer the head and breast darken considerably; the female is more plainly marked in brown and white and lacks the elongated tail. Flocks often move low over the water in tight, fast-turning formations.
It is one of the most vocal of ducks, the male giving a resonant, yodelling "a-aulik, a-aulik" year-round that carries far over open sea, often heard from distant flocks before they are even visible. It breeds sparsely on the alpine tundra of northernmost Scandinavia, with only a few thousand pairs in the Swedish mountains, but its real significance lies in winter, when large parts of the North European population gather in the Baltic — flocks of tens of thousands can be seen off Gotland, Öland and Blekinge, though this wintering population has declined dramatically since the 1990s, the main driver of the species' threatened status. It nests at mountain pools, where the female lays 6–9 eggs and incubates alone for about three and a half weeks, and it feeds by diving to the seabed for mussels, crustaceans, snails and other bottom-dwelling animals, regularly reaching 20–30 metres and documented even deeper, making it one of the deepest-diving ducks in the world.
Read about this species in Swedish →