The Harlequin Duck, Histrionicus histrionicus, is a small sea duck. Today, this is the only species of its genus. Two prehistoric harlequin ducks were described from fossils, although both were initially placed in a distinct genus: Histrionicus shotwelli is known from Middle to Late Miocene deposits of Oregon, USA and was considered to form a distinct monotypic genus, Ocyplonessa. Histrionicus ceruttii, which lived in California during the Late Pliocene, was at first taken to be a species of the related genus Melanitta. The species is traditionally considered monotypic. The Eastern and Western populations are sometimes recognized as two different subspecies, the Eastern race being the nominate H. histrionicus histrionicus, and the Western race as H. h. pacificus, but there has been doubt on the validity of this taxon.
From a distance, Harlequin Ducks look black or dark grey and can easily be confused with more common sea ducks, such as scoters. At close range, however, the adult male is striking and brightly coloured. It is characterized by slate blue plumage, chestnut flanks, and streaks of white on its head and body. The most distinctive markings on the head are a crescent-shaped white patch at the base of the short bill and a round white ear patch. The belly is slate grey.
Females and young birds lack the lustre of the drakes. The female has plain, brownish-grey colouring that is darkest on its head, a white patch extending below and in front of each eye, and a prominent white ear patch. The belly is white with brown speckles. Young birds strongly resemble the adult females. They have the white spot between the bill and eyes, as well as the prominent round ear patch. However, the feathers on the upper body of the young are darker than those of adult females, and the belly is more finely barred, giving an overall greyer appearance. The young males achieve some adult features during their first winter, but do not grow full adult plumage until two or three years of age.
Seen from afar, Harlequin Ducks can be distinguished from other sea ducks by several features. They have slighter bodies and shorter bills than scoters, and they raise and lower their heads and nod while swimming. The birds are also normally found in smaller flocks and closer to shore than other sea ducks. Female and immature birds do not have the white wing patches found on Buffleheads and White-winged Scoters.
Listen to the sound of Harlequin Duck
Copyright remark: Most sounds derived from xeno-canto
|wingspan min.:||63||cm||wingspan max.:||70||cm|
|size min.:||38||cm||size max.:||45||cm|
|incubation min.:||27||days||incubation max.:||29||days|
|fledging min.:||60||days||fledging max.:||29||days|
During winter, Harlequin Ducks congregate at traditional sites to feed in the swirling waters of shallow and rocky coastal areas. In northern wintering areas, they seek rocky shores and ledges near turbulent water where ice buildup is minimal.
Like many other waterfowl, male Harlequin Ducks leave the breeding areas once the female begins to incubate, or warm the eggs, usually by mid-June to early July. After leaving their mates, males migrate to specific sites to undergo their annual moult, or shedding of old feathers. Females normally join males at these sites and moult one to two months later.
Unlike other northern hemisphere ducks, Harlequin Ducks normally locate their nests beside fast-flowing streams. Observations of nest sites suggest that females may use the same site in consecutive years. The nest, lined with down, may be built on the ground under clumps of shrubs or under logs, in tree cavities, under bank overhangs, or even on bedrock ledges. In early summer, the female, or hen, lays three to eight cream to pale buff eggs at intervals of two to four days.
The hen incubates the eggs for 28 or 29 days until they hatch. During this time, she leaves the nest infrequently to feed, wash, and rest. Incubating birds may not leave the nest until closely approached. Nests are extremely difficult to find.
The female leads her ducklings to secluded streams within 24 hours of hatching. Here they learn to find aquatic insects and larvae in the cool and clear waters. The young are able to fly when they are about 40 to 50 days old.
Harlequin populations have a low reproductive rate and therefore might take longer to rebuild after a decline than do populations of other waterfowl. Factors such as the later age at first breeding, small average clutch size (set of eggs to be hatched at one time), and the high proportion of nonbreeding birds in some years may contribute to the low productivity of Harlequin Ducks. In some years fewer than half the females are thought to nest, possibly because insects are less abundant.
Wintering habitat consists of turbulent seas and the rocky parts of coastal areas. The birds locate their food by diving in shallow waters over wave-pounded rocks and ledges to find and pry prey from crevices. The most common food items include small crabs, amphipods, gastropods, limpets, chitons, blue mussels, and fish eggs.
The Harlequin Duck has high food energy requirements, probably because of its relatively small body mass and high metabolic demands, especially in colder parts of its range. Because a small bird can store fewer reserves than a large bird, Harlequins are less suited to survive extremely cold and stormy weather. They must feed continually to maintain their metabolism.
Video Harlequin Duck
On the Atlantic coast, the Harlequin Duck is “endangered” and occurs only in remote locations. Harlequins can be seen more easily in western Canada, where they are more abundant and occupy sites near urban areas. Globally, the Harlequin Duck occurs over a wide geographic range in four separate populations. Two populations occur in Canada: the western population along the Pacific Coast and the eastern population along the Atlantic Coast. Although there are an estimated 200 000 to 300 000 Harlequin Ducks in the western population, the eastern North American population today consists of fewer than 1 000 individuals. Historically, the endangered east coast population had been estimated at 5 000 to 10 000 birds. Rare vagrant and escapee in Europe.