Sunday, 10 March 2013

Week 11: Long-tailed Duck (Clangula hyemalis)

The long-tailed duck was @SpeciesofUK from 10th to 16th February 2013.

The long-tailed duck is a sea duck. Other sea ducks found in UK waters include eiders, scoters, goldeneyes and mergansers.

Male Long-tailed Duck
[Source: Rictor Norton & David Allen]

The long-tailed duck is not resident in the UK; it's a winter visitor. It's most common in estuaries and bays in northern Scotland but is also seen as far south as Norfolk.


The long-tailed duck's habitat stretches across the North Atlantic region, Alaska, northern Canada, northern Europe and Russia. It breeds in tundra marshes/pools and large mountain lakes.

Male Long-tailed Duck
[Source: Jan Svetlik]

After the post-breeding moult, long-tailed ducks gather for a large southward migration, around September. They mass in huge, spectacular groups, and fly south to winter in bays, estuaries, and occasionally on inland lakes.[1]

The most popular wintering site for the long-tailed duck is the Baltic, which sees them gather together in the millions.

The UK is a bit of an outpost. Around 11,000 long-tailed ducks visit the UK in winter, although they are concentrated around the north of Scotland.[2]

The global population of long-tailed duck is estimated at 6.2-6.8 million individuals. The wintering population in the Baltic has undergone a precipitous decline from 4.3m in 1992 to 1.5m in 2009.[3]

The main migration of birds home from the Baltic, across the Gulf of Finland, is spectacular, with up to 100,000 birds seen at once on late May evenings.[4]

Long-tailed Ducks Migrating in the Baltic
[Source: Cano Vääri]


The long-tailed duck gets its name from ... well, from the fact that it’s a duck with a long tail!

In North America, where the long-tailed duck is common, it used to be known as the oldsquaw ("old wife"), a name that may have come from a local belief that the spirits of old women pass into sea ducks.[5]

“Oldsquaw” is now considered offensive and most Americans have adopted long-tailed duck as the common name instead.

Long-tailed Duck or "Oldsquaw"
[Source: Gidzy]

Other regional American names for the long-tailed duck include butterfly coot, Florida longtail, ice duck, singing duck, sou-sou-sally, swallow-tailed duck and winter duck.[6]

In the UK, long-tailed duck is the only name that is really used.

All in all, the long-tailed duck is a relatively small sea duck. It has a rounded head and steep forehead.[7]

The greatly elongated tail feathers are only found on the male, and they really are a marvel.

Male Long-tailed Duck
[Source: Wolfgang Wander]

Even aside from the tail, there is something tasteful and well-ordered about the male's plumage. The female’s plumage is less exotic but it is still an attractive bird.

Female Long-tailed Duck
[Source: DickDaniels]

Long-tailed ducks have a complex moult and show a bewildering variety of patterns depending on their age, their sex and the time of year.[8] The colours are always a mixture of black, white and brown.

In total, the long-tailed duck's scapulars and side of head and neck are moulted three times a year, the upper mantle and rest of head twice a year, and the rest of the plumage once a year.[9]

Male Long-tailed Duck in Moult
[Source: DickDaniels]


During the summer, on the breeding ground, the long-tailed duck eats aquatic insects and invertebrates and also some plant material.[10]

In the winter, it eats a variety of marine food, including crustaceans, molluscs, worms, and fish.[11]

A key food source of the long-tailed duck in its favoured wintering site in the Baltic is the blue mussel, which is found there in abundance.[12] It swallow mussels whole, including the shell. Its digestive system crushes and digests the shell and the soft body.[13]

The long-tailed duck is an expert diver, regularly diving 20m when foraging and even down to an astonishing 60m, roughly equivalent to the height of a 20-storey skyscraper![14]

Long-Tailed Duck Diving
[Source: DaveMaherPhotos]

While most diving ducks paddle with their webbed feet, the long-tailed duck uses its partially folded wings to propel itself underwater.[15] When foraging for food, it can spend 3 or 4 times as long underwater as it does floating above water.[16]

While wintering out at sea, the long-tailed duck is restless. It flies low over the water in short flights, with stiff and shallow wing-beats, often tilting from side to side and constantly changing direction.[17]

Long-tailed Ducks in Flight
[Source: Eonian Art]

The long-tailed duck has a distinctive vocalisation, a nasal yodelling “ow ow-owdelee” which you can hear here.


Long-tailed duck pairs bond during the winter or on the spring migration home. The bond lasts until incubation begins.[18]

The long-tailed duck breeds from late May, in single pairs or in loose groups. They use a natural depression on dry ground in the arctic tundra as a nest, usually close to water. They line it with leaves and down.[19]

Female Long-tailed Duck on Nest
[Source: Howcheng]

The chicks leave the nest as soon as they are dry from birth and then swim and feed themselves immediately, mainly on insect larvae.[20] The female helps dislodge food items for them but otherwise they feed themselves. At 35-40 days, the young start to fly.[21]

Female Long-tailed Duck with Chicks
[Source: omarrun]

The males leave the females after incubation starts to gather together for a moult.[22] This is basically a bit of a jolly. The leave the females and ducklings and in some cases fly 1,000km for a temporary “moult migration.”[23]

The females, on the other hand, stay on the breeding ground to moult, although they do sometimes gather in groups, leaving their young together in a “creche.”[24]


The long-tailed duck population is in decline. Its wetland habitat is threatened by drainage, peat extraction and petroleum pollution.[25]

The long-tailed duck is susceptible to direct pollution from oil, from being trapped in fishing nets, and from hunting, which happens for example in Denmark and the USA.[26]

In 2006-07, in the Barents Sea, several thousand dead long-tailed ducks were found washed up on beaches.[27]

Strange but true…

Most ducks land in water by using their feet as brakes. The long-tailed duck doesn’t bother. It just belly-flops into the water with an almighty splash.[28]

[4] Birds (Collins)
[9] Birds (Collins)

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