OF NAMES “Ring-necked” for the chestnut-colored neck bands of breeding males; L. collaris, collared.
NATURAL HISTORY Despite their name, male Ring-necked Ducks have chestnut collars so faint they are difficult to see even at close range. From a distance their dark heads and backs, vertical white stripes on the leading edge of the flanks, and white ring around the bill tip make much better field marks—they might be more properly named “Ring-billed Ducks.”
Ring-necks tend to flock with members of their own kind on farm ponds and reservoirs; they almost never occur on salt water. Like most divers, they must run across the water surface for a considerable distance before taking flight. Wintering flocks frequent large, open bodies of water. In contrast, nesting pairs select smaller, secluded lakes and ponds—often surrounded by forest. Females build nests of grasses and aquatic plants, usually near or over water. Primarily vegetarians, their main foods include pondweeds, smartweeds, and occasionally insect larvae.
STATUS AND DISTRIBUTION Ring-necked Ducks are visitors and migrants to California, including both sides of the Sierra.
West Side. Fairly common fall and winter visitors to low-elevation lakes, ponds, and reservoirs the length of the West Side; rare nesters with breeding only documented at Buck’s Lake but probably breeds at other deep lakes of the northern Sierra; pairs in suitable Sierra breeding habitats have been seen in midsummer as far south as Madera County south of Yosemite National Park, suggesting a recent southward-range extension.
East Side. Uncommon fall visitors to larger lakes and reservoirs; hens with broods at secluded lakes in the Tahoe Basin, Meiss Lake (Alpine County), and at Crowley Lake.
Lesser Scaup
Aythya affinis
ORIGIN OF NAMES “Scaup” was modified from OE. scalp, shellfish, a food of this species; L. affinis, allied with or related to, refers to close relationship to the larger Greater Scaup (A. marila), a rare species in the Sierra (see Appendices 1 and 2).
NATURAL HISTORY As their name suggests, Lesser Scaup are slightly smaller than their close relatives, Greater Scaup. The two species are often lumped together by hunters who call them “blue-bills,” or “bluies,” instead of scaup.
Lesser Scaup are restricted to the Western Hemisphere, where they breed in subarctic wetlands of Alaska and Canada and winter as far south as northern South America. While they also occur in coastal waters, Lesser Scaup are much more numerous in California’s interior than Greater Scaup. In winter they primarily consume animal foods including crustaceans, mollusks, and aquatic insects obtained by diving. Lesser Scaup tend to feed in shallower water than some other divers, usually about 5 or 6 feet deep, but sometimes they dive up to 20 feet.
STATUS AND DISTRIBUTION Lesser Scaup are winter visitors and spring and fall migrants to California, and there are no breeding records for the Sierra region.
West Side. Uncommon visitors to most large foothill lakes and reservoirs up to about 3,000 feet in the central Sierra.
East Side. Uncommon visitors to most large lakes and reservoirs, annual records from Honey Lake, Sierra Valley, Lake Tahoe, Topaz Lake, Mono Lake, and Crowley Lake.
Harlequin Duck
Histrionicus histrionicus
ORIGIN OF NAMES “Harlequin” for this species’ multicolored plumage, reminiscent of the brightly colored characters of the pantomime stage; L. histrionicus, related to L. histro, actor.
NATURAL HISTORY Nesting Harlequin Ducks prosper amid swirling torrents and rapids of mountain streams. According to William Dawson (1923): “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 (1891) 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 4000 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, Harlequins elsewhere nest on the ground, under the shelter of driftwood or rocks, and always beside swift, flowing rivers. They 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. Females care for their precocial young alone, when they often move to slower stretches of nesting streams.
Harlequins are adept underwater swimmers, and they seek clear, cold rapids, where they search rock crevices for aquatic insects including the adults, nymphs, and larvae of caddisflies, mayflies, and stoneflies. They use their huge feet to navigate the bottoms of rushing steams over wet, polished stones—much like American Dippers, which share their summer haunts and their favored prey.
STATUS AND DISTRIBUTION Most Harlequins currently wintering along the California coast are from northern breeding populations, but a few pairs probably nest along remote rivers of the Sierra each year in greatly reduced numbers from their historical population.
West Side. Rare, all historical records from turbulent headwaters from the Stanislaus River south to the upper San Joaquin River and specific nesting localities included Griswold Creek (tributary to the Stanislaus River), South Fork of the Tuolumne River, Cherry Creek (tributary to the Tuolumne River), South Fork Merced River, Lake Ediza (9,300 feet, near the headwaters of the San Joaquin River), and the South Fork Merced River in Yosemite Valley; also observed along the South Fork Kaweah and the South Fork Kings Rivers, but nesting there was not confirmed. Currently rare, casual, or absent from most of the historical breeding range in the Sierra; confirmed breeding records since the early 1970s include above Salt Springs Reservoir on the Mokelumne River, on the Feather River near Thermalito Forebay, and, most recently, on the Merced River in Yosemite National Park in 2002; recent breeding season observations of Harlequins (breeding status not confirmed) include North Fork Feather River, North Fork American River, Rubicon River, Silver Fork of the South Fork American River, North Fork Mokelumne River, Tenaya Creek and the South Fork Merced River in Yosemite National Park, the upper San Joaquin River, and below Friant Dam on the lower San Joaquin River.
East Side. No historical or recent records.
TRENDS AND CONSERVATION STATUS Harlequin Duck was added to California’s list of Species of Special Concern in 2008. Despite its rarity and declining status, this species has not been listed as either Threatened or Endangered—mostly because it is seen so infrequently and so little is known about its recent breeding status in the Sierra. The exact cause of the Harlequin’s decline is unknown. Increased disturbance from human recreational activities and damming of historical nesting streams have also reduced the suitability of many Sierra rivers for nesting Harlequins. Historical gold mining had severe but unmeasured effects on their riverine habitats and breeding populations.
Bufflehead
Bucephala albeola
