The Long-Tailed duck (Clangula hyemalis), once known as oldsquaw, is a medium-sized sea duck. It is the only living member of its genus, Clangula. This was formerly used for the goldeneyes, with the long-tailed duck being placed in Harelda, but the latter is the type species of the genus.
Long-tailed ducks have a fairly large range compared to other waterfowl. Its biogeographic range, including breeding and non-breeding seasons, has been estimated to include 10,800,000 km2. Long-tailed ducks are residents of the circumpolar region and are regularly found breeding on the Arctic coasts of Canada, Alaska, United States of America, Greenland, Iceland, Norway, and Russia. They winter further south in the United Kingdom, North America, Korea and on the Black and Caspian Seas.
Long-tailed ducks reside in a variety of habitats. Generally, they winter in the open ocean or large lakes and summer in pools or lakes in the tundra. They prefer to breed in habitats that provide both an aquatic and terrestrial environment in close proximity, for example: marshy grass tundra in the Arctic, deltas, promontories, coastal inlets and offshore islands are all suitable. Habitat mosaics with damp depressions such as bogs and pools of standing water are also popular breeding sites. A study of summer distributions of long-tailed ducks as well as related species found that shallow water habitats are preferred when individuals are molting. This may be because molting individuals require protection from predation and environmental elements such as wind, waves and ice while still having a constant and abundant food source. Non-breeding long-tailed ducks reside far offshore in fresh estuarine, saline, or brackish waters. Though rare, they can be found wintering on large and deep freshwater lakes.
Long-tailed ducks are mid-sized birds with long, dark tails and gray legs and feet. The species received its common name from the two long and slender tail-feathers that extend behind adult males. Plumage coloration and general size vary between adult males and females. While adult drakes range in size from 48 to 58 cm long, adult hens are between 38 and 43 cm long. Adult males weigh approximately 0.91 to 1.13 kg and adult females weigh about 0.68 to 0.91 kg. Long-tailed ducks of both sexes shift between three distinct plumages and adult males display an additional alternate plumage in the winter.
In the winter, adult males are white on their crowns, necks and throats that extend down to the breast. The white throat contrasts sharply with a large, black breast-band. Males also feature a gray patch surrounding their eyes, and a black patch that extends from their ears. Bills are dark with a pinkish band across the middle. Their bellies and undertail coverts are white. They exhibit black tail-feathers, rumps and backs. Wings are black with white scapulars at the base. Winter females have white faces, necks, and throats with brown crowns and brown ear patches. They also feature a broad breast-band, but it is brown in color. Their backs, wings and tails are also brown, while their bellies and undertail coverts are white. Females' bills are a dark blueish gray.
Summer plumage: Males have black head, chest, and wings. Gray face patch surrounding eyes. Upper back feathers long, and buffy with black centers. Central tail feathers very long. Females have mostly dark head and neck, with white around eyes, extending in a thin line toward the ear. Back and breast are variably brown or gray. Eyes brown.
Like most members of the Anatidae family, long-tailed ducks are socially monogamous. Long-tailed ducks may breed in single pairs or loose groups. Breeding pairs can form as early as individuals reach the breeding grounds. Pairs can re-form for several years or individuals may select new mates each mating season. Breeding may be initiated before spring breeding plumage develops, but in most cases, breeding occurs after.
Long-tailed ducks engage in an elaborate courtship process, though sexual selection has only been studied superficially. Males will approach available females with an upright tail and bill held outwards, a few inches from the surface of the water. When closer to his potential mate, the male will bow and then pull his head back with his bill held upward. As he is lowering his head, he will emit calls. A series of four or five calls with deep notes have been observed. These calls often attract other males and they often physically fight and chase each other for the available female. Females call in response to initial calls from the males and hold their head close to their body to indicate availability. Females will then lead males to a mating location.
Breeding can begin as early as May, but varies depending on the location of the breeding ground and the presence of mates. Long-tailed ducks can begin mating as early as their second year after birth. They mate near open water, either freshwater or marine, and try to nest on dry ground hidden among rocks or under plant growth. Nests are bowl-shaped and constructed by the female. They consist of nearby grasses and females pluck down from their own bodies to line the nest.
Females usually lay 6 to 8 eggs: on average, laying one egg per day. Clutch sizes of up to 17 have been recorded, but this is likely the result brood parasitism as some females will lay eggs in other's nests. Females will raise one brood per season, but can lay eggs several times if unsuccessful. Since fall migration occurs relatively late, long-tailed ducks have a long breeding season and can attempt raising a brood several times. Once eggs are laid, the incubation period lasts from 24 to 30 days. Young ducklings remain in the nest until they fledge after 35 to 40 days. The fledglings form groups of 3 to 4 broods that are tended by older females.
The Long-tailed Duck is one of the deepest diving ducks, and can dive as deep as 60 meters (200 feet) to forage.
Of all diving ducks, the Long-tailed Duck spends the most time under water relative to time on the surface. When it is foraging it is submerged three to four times as much as it is on top of the water.
Unlike most ducks, which molt twice per year, the Long-tailed Duck has three distinct plumages each year, achieved in a complex series of overlapping partial molts. The Definitive Basic Plumage is never worn in its entirety, as portions of Alternate are retained through the summer and elements of the Supplemental are acquired before all of Basic Plumage is obtained. Therefore change in plumage seems continuous from April to October.
Unlike other waterfowl, the Long-tailed Duck wears its "breeding" or Alternate Plumage only in the winter. It gets its "nonbreeding" or Basic Plumage in the spring and wears it for the breeding season. Most other ducks wear the nonbreeding plumage only for a short period in the late summer.
The oldest recorded Long-tailed Duck was a female, and at least 17 years, 1 month old when she was found in Alaska, the same state where she had been banded.
Justification (IUCN Red List)
This species has been listed as Vulnerable because of an apparent severe decline detected in the wintering population in the Baltic Sea between the early 1990s and late 2000s. This rate of decline implies that the global population will undergo at least a ≥30 decline over three generations (1993-2020), even when factoring-in uncertainty regarding the sizes and trends of other populations. Improved knowledge regarding populations outside the Baltic Sea might lead to the species being uplisted to Endangered if the overall rate of decline can be confidently shown to be very rapid.