Fr:  Arlequin plongeur
    Ang:  Harlequin Duck 
    All:  Kragenente
    Esp:  Pato Arlequín
    Ita:  Moretta arlecchino
    Nd: Harlekijneend
    Sd: Strömand
Photographers:
John  Anderson 
  John Anderson Photo Galleries 
Tom  Grey
  Tom Grey's Bird Pictures 
Paul  Guillet
    Photos d’Oiseaux  
Tom  Merigan
    Tom Merigan’s Photo Galleries 
Otto  Plantema 
  Trips around the world 
Text by Nicole Bouglouan
Sources:
HANDBOOK OF THE BIRDS OF THE WORLD vol 1 by Josep del Hoyo-Andrew Elliot-Jordi Sargatal - Lynx Edicions - ISBN: 8487334105
THE HANDBOOK OF BIRD IDENTIFICATION FOR EUROPE AND THE WESTERN PALEARCTIC by Mark Beaman, Steve Madge - C. Helm - ISBN: 0713639601
L’ENCYCLOPEDIE MONDIALE DES OISEAUX - Dr Christopher M. Perrins - BORDAS - ISBN: 2040185607
GUIDE DES CANARDS, DES OIES ET DES CYGNES – de Steve Madge - Delachaux et Niestlé - ISBN: 2603013769
Animal Diversity Web (University of Michigan Museum of Zoology)
All About Birds (Cornell Lab of Ornithology)
Bird Web (Seattle Audubon Society)
What Bird-The ultimate Bird Guide (Mitchell Waite)
Harlequin Duck 
      Histrionicus histrionicus
Anseriformes Order – Anatidae Family
INTRODUCTION:
    The Harlequin  Duck is a beautiful and powerful sea duck. It favours the mountain streams in  summer, diving and swimming against the current of rushing rivers. During winter,  it occurs at sea in rocky coastal waters and wild coastlines where the waves  break on rocks.
    The name  of this small sea duck “harlequin” comes from its colourful plumage. It is the  only remaining species of the genus Histrionicus and it is monotypic. It breeds  in NW and NE North America, Greenland and Iceland, and disperses along the sea  coasts in winter, within the breeding range. 
    The Harlequin  Duck is not threatened and the overall population trend is currently increasing. 

DESCRIPTION OF THE BIRD:
      Biometrics:
    Length:  38-50 cm
    Wingspan:  61-70 cm
    Weight:  M: 580-750 g – F: 485-680 g
The adult  male has blue-grey plumage, darker when seen at distance. It has distinctive  white markings on head and body. 
    On the  upperparts, upper back and mantle are darker bluish. The white scapulars show  narrow dark grey fringes. Tail and rump are black. The upperwing is blue-grey  with blackish flight-feathers. We can see a short white wingbar and a  purplish-blue speculum. 
    On the  underparts, the plumage is blue-grey with conspicuous chestnut flanks, and  long, white, vertical bar bordered black on each side of the breast. There is a  small white spot on rump sides. The underwing is mostly brown. 
The head  is blue-grey with conspicuous white crescent at base of bill extending up to  lores and forecrown, a small white ear patch and a vertical white stripe on  neck sides. A broad black median stripe extends from the upper base of the bill  to the rear crown, bordered on both sides with white and chestnut. We can see a  white neck-collar broken at front and back. 
    The bill  is grey-blue with paler tip. The eyes are reddish-brown. Legs and feet are  bluish-grey. 
The adult female has dark brown head and neck with white patch behind, below and in front of the eye to forehead. The plumage is blackish brown, mostly greyish below and whitish on the undertail-coverts. Except the eyes, the bare parts are duller than in male.

The male  in eclipse plumage resembles female, but darker brown to dark grey with white,  black-fringed innermost tertials.
   
    The juvenile  also resembles female but it has paler upperparts and more spotted underparts. It  attains the full adult plumage in the second year. 

RANGE: 
    The Harlequin  Duck breeds in Alaska and Yukon, S to SE Idaho, California and Massachusetts. It  also breeds in E Canada, S to Gulf of St Lawrence, Greenland and Iceland, and  probably Baffin Island.
    It winters  along the coasts off Korea and Japan, and in USA in Maryland and N California.  
HABITAT: 
    The Harlequin  Duck breeds along the fast flowing rivers in hilly and mountainous country, and  around rapids and waterfalls, but usually in rocky area with trees. It may  reach high elevations of up to 3350 metres.
    It winters  along rocky coastlines, in shallow waters usually within 300 metres from the  shore. It often dives among the heavy surf of the breaking waves. It is rarely  seen in sheltered bays, but sometimes around harbours. 

CALLS AND SONGS: SOUNDS BY XENO-CANTO 
    The Harlequin  Duck is usually silent outside the breeding season. The male becomes more vocal  during the displays, uttering a high-pitched squeaking whistle, increasing as  displays intensify. The female gives several short, harsh calls.
BEHAVIOUR IN THE WILD: 
    The Harlequin  Duck feeds primarily on molluscs, crustaceans and insects (adults, larvae and  pupae) in spring and summer. 
    At sea,  its diet consists mainly of mussels, shellfish, aquatic insects, crustaceans  and occasionally small fish and marine worms. 
    On rivers  during the breeding season, it feeds mostly on aquatic insects and it may take small  amounts of plant material. 

The Harlequin Duck feeds mostly by diving, often in tight-packed flocks in intertidal and subtidal zones. It also dabbles and head dips in shallow water. It takes aquatic preys from rocks just below the surface, or skims insects from the surface. But when feeding in groups, the ducks drive into water 3-4 metres deep, and they catch preys within 15-20 seconds of diving.
On rivers, its behaviour is close to that of the Torrent Duck in the Andes. It is able to swim easily against the current by using the swirls, but also the calm waters close to the shore. It also rushes on the water, mid-flying and mid-swimming, or jumps into the water from a rock.

During the  breeding season, the Harlequin Duck female looking for a mate always chooses a  mate with bright plumage, indicating a powerful, healthy male, able to defend  her against the rivals during this period. Male’s plumage is usually affected  by age and such duck does not attract the females.
    The males  perform courtship dances to attract females. They shake both head and tail while  producing high-pitched whistles when they swim around females. Males also  perform short flights close to the water surface. 
    They are  monogamous for a single breeding season. The male usually helps in nest-building,  but it leaves and migrates back to the ocean for moulting as soon as the female  starts to incubate. She rears the chicks alone.  

The Harlequin Duck is not truly migratory, but it disperses along the sea coasts in winter, within its breeding range. Males leave first in June, and females and young in early September. They moult during this period. They return to their breeding areas in late April and courtship displays often continue until mid-June.
The Harlequin Duck has fast, direct flight, usually flying low over the water and following the river’s course. It needs some running before rising into the air.
REPRODUCTION OF THIS SPECIES: 
    The breeding  season starts in May-June. According to weather conditions, the peak laying  occurs in the first half of June. 
    The male  defends its mate but it is not territorial. The nest is on the ground, often on  small island in river, and sometimes behind waterfalls. It is made in a hollow,  lined with grass and down, and concealed among tall vegetation, among rocks, in  cavities or occasionally in tree-holes up to 8 metres above the ground and  close to the water. 
The female lays 5-8 yellowish eggs and incubates alone during 27-29 days. At hatching, the chicks have grey down above and whitish below, and white cheeks. They fledge between 50 and 70 days after hatching, depending on the range. They are independent after the post-breeding dispersion to the seacoasts. They usually live in flocks during the winter.

PROTECTION / THREATS / STATUS: 
    The Harlequin  Duck is preyed upon by the Arctic Fox and the Grey Wolf, but also by Bald Eagles, jaegers and ravens, and  on rivers by otters on adults, and mink and martens on nests. The species is  widespread and common, and even locally abundant.
    The population  is estimated to number 190,000/380,000 individuals (2006), and is currently  stable or even increasing. 
    The Harlequin  Duck is evaluated as Least Concern. 
