Clangula hyemalis
long-tailed duck
(Also: long-tailed duck;oldsquaw; oldsquaw)

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 Duck Clangula hyemalis", 2004; "Long-tailed Duck (Clangula hyemalis)", 2002)

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 Duck Clangula hyemalis", 2004; Fischer and Larned, 2004; "Clnagula hyemalis (Linnaeus, 1758)", 2005)

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.

During the spring and summer, adult males feature black crowns, necks and throats that extend through the breast. Their backs, tails and wings remain black, but their scapulars are buff and mottled with black. Their gray eye patches remain, but are accented with white. Their bills are dark, with a blueish band. Spring females are overall brown, with brown faces and a small white patch surrounding each eye. They also often feature a white crescent across their lower necks. Their brown breast band extends further into the belly, but the undertail coverts remain white.

In late summer, males begin to develop a third plumage that is an intermediate between the winter and spring plumages. Their throats and necks become white and their bills develop a pink band.

Young long-tailed ducks look like miniature adult females, but young males begin to resemble adult males by late fall. (Bent, 1987; "Long-tailed Duck (Clangula hyemalis)", 2002; Murphy, et al., 2001)

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. (Bent, 1987; "Long-tailed Duck Clangula hyemalis", 2004; Goudie and Ankney, 1986)

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. (Bent, 1987)

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. (Bent, 1987; "Long-tailed Duck Clangula hyemalis", 2004; Braune, 2010; Goudie and Ankney, 1986; "Clnagula hyemalis (Linnaeus, 1758)", 2005)

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. ("Long-tailed Duck Clangula hyemalis", 2004; Braune, 2010; Fischer and Larned, 2004; "Clnagula hyemalis (Linnaeus, 1758)", 2005)

While eggs are being laid, the male will reside in the open water and help defend the nest. During the incubation period between late June and early September, the male will leave and begin molting. The newly laid eggs are then incubated and defended by the female for 24 to 30 days. Although newly hatched young can feed themselves, they are fed and closely tended by their mother. When the young begin walking, the mother leads her brood over to the water and teaches them to dive for food. First flight can occur anywhere between 35 to 40 days old. Anywhere between August and October, the mothers will leave their young to molt and ducklings will gather into large groups in and around the water. These groups are often tended by slightly older females. (Bent, 1987; "Long-tailed Duck Clangula hyemalis", 2004; "Clnagula hyemalis (Linnaeus, 1758)", 2005)

According to a study of body mass dynamics in adult females during incubation, females lose proportionately less mass and rely less on endogenous reserves to lay and incubate eggs than other diving ducks. Specifically, females lose approximately 7% of their mass during incubation: average weight is 618 g at clutch completion and then drops down to 575 g at hatching. Because females are relatively smaller than other waterfowl breeding in the tundra and have access to high-quality nutrients, long-tailed ducks are able to maintain high nesting attendance rates and constant incubation without losing too much of their endogenous reserves. (Kellett, et al., 2005)

The average lifespan of long-tailed ducks is 15.3 years. A single case of an adult male reaching the age of 22 years in the wild has been reported. No extensive studies on lifespan in captivity have been conducted. Several studies suggest that longevity is linked to food availability, stable environment, absence of disease and toxic materials such as lead and mercury.

Average nesting success is 30% in long-tailed ducks and on average, 10% of ducklings survive to 30 days old. Duckling survival, however, is highly variable to location of breeding and fluctuations in breeding environment. Average survival post-nesting for females is approximately 74%. (Braune, 2010; Kellett, et al., 2005; Schamber, et al., 2009)

Long-tailed ducks are fully migratory and diurnal. They are highly gregarious within their own species but tend to avoid inter-species interactions. They spend much time acquiring food and dive relatively far offshore for prey. Because of their body size and physiological needs, long-tailed ducks forage longer than other diving ducks and prefer to eat benthic prey, including crustaceans and amphipods. (Bent, 1987; Kellett, et al., 2005)

Long-tailed ducks have two major migrations: the fall migration south in early September and the spring migration north in early May. The southward fall migration occurs after a flightless molting period for both males and females. While males molt between late June and early September, females molt between early August and early October. Both males and females gather in flocks during their flightless molting periods and generally complete their migrations in groups as well. Females must molt before their migration, so they leave their newly-fledged ducklings to molt elsewhere. Fledgling ducklings then gather into large groups until they begin their first fall migration. ("Long-tailed Duck Clangula hyemalis", 2004; "Long-tailed Duck (Clangula hyemalis)", 2002; Lacroix, et al., 2003)

The home ranges of long-tailed ducks and related species such as common eiders (Somateria mollissima) and spectacled eiders (Somateria fischeri), have not been studied yet.

Long-tailed ducks have an extensive variation of calls that are used primarily for intra-species communication. A fairly vocal species in the Anatidae family, long-tailed ducks can make a variety of growling, clucking, squawking, and yodeling sounds. The calls of individuals have been described as guttural or nasal and are audible across fairly large distances. When mother long-tailed ducks lead their progeny to the nearest water sources, they use specific calls as cues for the young to dive in unison. Calls are also an integral part of mating. Males use a series of four or five calls in deep notes to advertise availability for mating. Females emit single calls or growls to acknowledge potential mates or respond to initial calls from males. (Bent, 1987; "Clnagula hyemalis (Linnaeus, 1758)", 2005; Murphy, et al., 2001)

During the breeding season, males confront competitors through calls, physical contact, chases and visual cues such as spreading wings and tilting heads upward. Females defend young by spreading wings and splashing water, possibly to draw attention away from the vulnerable young individuals. Like most ducks, long-tailed ducks perceive their environment through visual, auditory, tactile and chemical stimuli. (Bent, 1987; "Clnagula hyemalis (Linnaeus, 1758)", 2005; Murphy, et al., 2001)

Long-tailed ducks are generalists that consume a large variety of prey. Animal foods that are commonly eaten by long-tailed ducks include: crustaceans, mollusks, marine invertebrates, small fish, fish eggs, freshwater insects and insect larvae. Some plant material that is also consumed includes: algae, grasses, seeds and fruits in the tundra biome. Studies show that mature adults prefer marine animals. Specifically, they tend to eat blue muscles, Idotea baltica (isopods), northern lacuanas, and Amphipoda crustaceans which yield higher energy per gram of live mass than other available prey. ("Long-tailed Duck Clangula hyemalis", 2004; "Clnagula hyemalis (Linnaeus, 1758)", 2005; Kellett, et al., 2005)

Mature adults typically forage diurnally, about 80% of the day, during the winter months. Usually, individuals dive with submerged times ranging from 25 to 60 s and pick epibenthos within 100 m of the shore. Since long-tailed ducks are relatively small when compared to their marine Anatidae counterparts, they must maintain a particular diet for physiological and thermoregulatory purposes.

Long-tailed ducks have several physical characteristics that make them successful predators. First, they have chisel-shaped bills that curve at the tip which would help grab epibenthos prey from their substrates. Second, long-tailed ducks have smaller bills, allowing them to efficiently pick small, motile crustaceans. Finally, the body shape and structure of mature adults aids in diving and agility in water, giving individuals a powerful advantage over their primarily cursorial or sessile prey. (Goudie and Ankney, 1986)

Long-tailed ducks are most vulnerable to predation on land: newly hatched ducklings, freshly laid eggs and molted, flightless adults have the highest mortality rates. Females camouflage their nests and lay eggs close to the water so when ducklings hatch, the dangerous journey to the water is shortened. Males remain on breeding grounds while females lay eggs to help defend the nest from predation. Newly molted males and females stay in flocks in an attempt to lessen the chance mortality just as ducklings travel in large creches before their fall migration.

Avian predators of long-tailed ducks include mew gulls, glaucous gulls, and jaegers. In coastal breeding grounds, Arctic foxes are common predators. When long-tailed ducks mate further inland, near freshwater lakes, red foxes become serious predators. (Lacroix, et al., 2003)

Long-tailed ducks are important predators of crustaceans, mollusks, marine invertebrates and small fish in holarctic regions. Long-tailed ducks are also a significant food source for avian predators, such as gulls and jaegers, and terrestrial predators, such as roving dogs and foxes. They are vulnerable to diseases including recorded cases of avian botulism, avian influenza and avian cholera. Few studies have investigated parasitic, commensal or mutualistic relationships of long-tailed ducks. ("Long-tailed Duck Clangula hyemalis", 2004; Lacroix, et al., 2003; North and Lair, 2006)

Long-tailed ducks help regulate populations of prey species including insects, mollusks and crustaceans. The species is hunted for sport in Denmark. Eggs and adults are part of the traditional diet of some Inuit communities. ("Long-tailed Duck Clangula hyemalis", 2004; Goudie and Ankney, 1986; Murphy, et al., 2001)

There are no known direct adverse effects of long-tailed ducks on humans.

Clangula hyemalis is the sole species of its genus, and thus is an interesting organism to study and protect. Although multiple references claim long-tailed ducks are the most prolific species of sea duck, population estimates are often unreliable and cursory. Though long-tailed ducks are fairly abundant, have a large geographic distribution and consume various animal and plant matter, estimated populations levels have been decreasing slightly over the last decade. In North America, the long-tailed duck population has declined by almost half in the last three decades. Because of wetland habitat degradation through petroleum pollution, drainage and peat extraction, important breeding sites for mature adults are being destroyed. There have also been reported cases of mortality from lead, mercury and oil pollution as well as entanglement in fishing nets. Long-tailed duck populations recently suffered significant losses because of an outbreak of avian cholera. Individuals are also believed to be susceptible to avian influenza. Currently, it is estimated that 6,200,000 to 6,800,000 mature individuals populate the arctic region. ("Long-tailed Duck Clangula hyemalis", 2004; Braune, 2010; "IUCN Red List of Threatened Species", 2010; North and Lair, 2006)

The common name “long-tailed duck” is synonymous with “oldsquaw,” a term used primarily in older texts. “Long-tailed duck” was adopted instead and the preferred classification of this species changed from Harelda to Clangula. ("American Ornithologists' Union", 2000)