The Field Guide to the Birds of the Sierra Nevada Project

Featured Species: Harlequin Duck

Harlequin Duck (Histrionicus histrionicus)
(Harlequin for this species = multi-colored plumage, reminiscent of a traditional character in pantomime who wore brightly-colored costumes on the stage; L. histrionicus, related to L. histro, actor)

Description.

L: 15-18" W: 7-8.5"

Relatively small duck with a sturdy, chunky body built for survival in a physically demanding environment. Forehead is abrupt with a rounded crown, set atop a thick neck. Bill small, light blue-gray fading into a pale, whitish tip. Tail, fairly long, thin, and pointed. Tail is generally held up at an angle when relaxed and down in the water when feeding or anxious.

Adult Male (Breeding): Strikingly patterned, stunning and unmistakable; this plumage is acquired during first winter. Displays seemingly random splashes of bold white against a sea of blue-gray, appointed with touches of rich chestnut. Dramatic and irregular plumage patterns tend to camouflage Harlequins against a background of turbulent water, similar to the "dazzle pattern" boldly painted on old battleships. Wings, entirely dark, save two tiny white markings on the wing coverts. In optimum conditions can show a dull purplish sheen on the secondaries-the only diving duck to possess this feature. Legs and feet, blue-gray.

Adult Male (Nonbreeding): Similar to adult female, showing faint pattern of the breeding male with a hue of warmth on the flanks and touches of white on the sides of the breast and tertials.

Adult Female, Juvenile: Nearly indistinguishable. Overall dull brown with a pale, dingy belly. Head marked with white spots on the face and ear, and supraloral area variably bisected with a dark loral patch. Flanks and breast only slightly paler than the head and back.

Voice: Most common call is a soft squeak; females also give harsher ek-ek-ek calls when disturbed or searching for young.

Similar Species: Along high Sierra rivers, distinguished from Common Merganser and Mallard by overall coloration, small size, shape of bill, and patterns of white on head and body (adult male only).

Natural History. Unlike most other waterfowl, Harlequin Ducks prosper amidst swirling torrents and rapids of mountain streams-a Sierra bird habitat they share only with American Dippers. According to the early California ornithologist, William Leon Dawson: "A baby Harlequin is as thoroughly at home in wild waters as a baby trout. The trout we may seduce with worm or fly, but until we have devised an equally interesting method for attracting young Harlequins, our meetings are likely to be infrequent." As Dawson implied, Harlequins were considered rare in the state by the early 1920s.

In the late 1870s, Lyman Belding reported "I have noticed many of these ducks on the principal streams of Calaveras and Stanislaus Counties in the summer... I find young broods from about 4,000 feet upward, the earliest apparently hatched about the first of June, or earlier, and have often surprised the mother ducks with their broods hidden in Saxifrage...when I approached within a few feet of the brood...all would hurriedly swim from me, vigorously using both feet and wings to propel themselves against or with the rapid currents...".

While no nests of these hardy ducks have been described in California, elsewhere in their range Harlequins usually nest on the ground, under the shelter of driftwood or rocks, and always beside swift flowing rivers. Harlequins sometimes nest on cliff ledges and in cavities in trees and stumps lined with conifer needles, mosses, or leaf litter. Nest building begins from early May to early June, and they only produce one brood per year. Clutches may contain 3 to 9 eggs (usually 5 to 7), and the young hatch in 28 to 30 days. Females care for their precocial young alone, when they often move to slower stretches of their nesting streams.

Harlequins are adept underwater swimmers, and prefer to forage in clear, cold rapids, where they search rock crevices for aquatic insects. They use their huge feet and partially opened wings to navigate the bottoms of rushing steams over wet, polished stones. On their breeding grounds, they primarily consume aquatic insects including the adults, nymphs, and larvae of caddisflies, mayflies, and stoneflies. While they sometimes forage for small, intertidal fish in winter, they are not known to eat trout on their breeding grounds. They often swim with a curious, exaggerated head-thrusting behavior that is reminiscent of American Coots and Common Moorhens. They roost on streamside rocks, boulders, and logs. In flight they appear small and dark as their rapid wing-beats propel them low over the water.

Distribution and Habitat. Harlequin Ducks occupy two distinct geographical areas within the state: the coast in winter (October through April) and the western slope of the Sierra for breeding (May through September), at least historically. Most Harlequins currently wintering along the California coast are primarily from northern breeding populations, but a portion of the historical wintering population probably nested in the Sierra. West slope: Turbulent headwaters of Sierra streams from the Stanislaus River south to the upper San Joaquin River formerly harbored nesting pairs of Harlequins. Specific nesting localities in the central Sierra included: Griswold Creek, tributary to the Stanislaus River; South Fork of the Tuolumne River; Cherry Creek in upper Tuolumne basin; South Fork Merced River; Lake Ediza (9,300 ft) near the headwaters of the San Joaquin River; and the Merced River in Yosemite Valley. They were also observed historically along the South Fork Kaweah and the South Fork Kings rivers, but apparently nesting was never confirmed.

Despite the irregular, but continued, presence of Harlequin Ducks in California's coastal waters, they are extremely rare or absent from most of their historical breeding range in the Sierra. The only recent breeding records were flightless young observed above Salt Springs Reservoir on the Mokelumne River (1971, 1972, 1976), and a female with five young at Thermalito Forebay, near Oroville, Butte County (1975). Recent breeding season observations of Harlequins (breeding status not confirmed) on the west slope include: a male on Tenaya Creek below Snow Creek in Yosemite Valley (1972); a pair on the South Fork Merced River near Wawona, Yosemite National Park (1977); 4-5 individuals "in female plumage" on the North Fork Mokelumne River at about 4,720 feet (1979); Wawona Campground, South Fork Merced River, Yosemite National Park (1981); females (three individuals and one pair) on the North Fork American River from 4,600 to 5,500 feet (1992, 1993, 1994, 1998); a pair on the Silver Fork of the South Fork American River at about 4,000 feet (1997); one male on the North Fork Feather River (1999); two males and a female at Lake Millerton (1999); a female below Friant Dam on the San Joaquin River (2000); and, several sightings along the Rubicon River in the mid-1990s. East slope: no records.

Conservation Status. The California Department of Fish and Game considers the Harlequin Duck to be a Species of Special Concern (First Priority). Despite its rarity and declining status, this species has not been listed as either Threatened or Endangered--mostly because Harlequins are seen so infrequently and so little is known about their occurrence in the Sierra. The exact cause of their decline is unknown but has been attributed to persecution by fishermen who falsely accused them of eating trout fry. Increased disturbance by fishermen, kayakers, and backpackers, and damming of historic nesting streams, have also reduced the suitability of many Sierra rivers for nesting Harlequins. However, the scattered observations of Harlequins in the summer suggest that at least some pairs may still breed annually along remote rivers of the Sierra.

Past Featured Species:

Common Loon