WGFD: Report Harlequin Duck observations
by Wyoming Game and Fish
May 22, 2012
The Harlequin Duck is one of Wyoming’s most rare, beautiful, and unusual waterfowl species. Wyoming Game and Fish Department biologists expanded their survey efforts in 2002, through the federally funded State Wildlife Diversity Grant program, to more thoroughly document the distribution and number of nesting pairs in Wyoming. Every five years, the Wyoming Game and Fish Department oversees a survey in May to count pairs in the pre-nesting season. This year will be the third survey, and the department is requesting help from the public to collect additional sightings of this colorful duck.
The common name, harlequin duck, reflects the unusual plumage of the male that often astounds first-time viewers. White blazes and a white ear spot stand out against a blue-gray back, chestnut colored sides and crown, and a black rump. Although unmistakably bright, this patterning provides excellent camouflage in rushing riffles and the bright glare of mountain streams. The light gray female is much drabber compared to her mate. Distinguishing marks include a small white ear spot and light coloration at the base of the bill.
Harlequins nest on remote, pristine mountain streams in northwestern Wyoming and winter on the Pacific coast in British Columbia. Ducks nesting in Wyoming represent the farthest eastern extension of the Pacific coast breeding population. Little is known about migration routes or timing, but harlequins began showing up in Wyoming in early May. Pairs are often seen on rivers and lakes near the mouths of nesting streams early in the season before run-off begins and stream volumes increase.
When the ducks move up into traditional nesting streams, males guard their mates very closely. When the female has completed laying eggs in mid to late June, the male departs, leaving her the work of incubation and brood rearing. Groups of males are sometimes seen hanging out on mountain lakes in June and July before they fly back to the Pacific coast.
Females and young (who are similar in appearance to the female) remain on nesting streams until the young develop flight feathers in late August to mid September. Adult females will sometimes depart for the coast before their young, so migration routes appear to be genetically determined.
The ducks are secretive and somewhat sensitive to human presence. Repeated human disturbance to nesting areas has resulted in abandonment of some traditional nesting streams in parts of the western United States. Harlequins will slip away out of sight if disturbed. , If you encounter pairs or family groups, avoid displacing the ducks from their nesting habitat by sitting quietly out of sight, shielded by vegetation. Using patience and care, it is possible to watch pairs forage for invertebrates (their main food) in riffles and pools. Ducks will often haul out on banks or gravel bars to rest and preen also.
Observers are requested to report location, date, number and sex of ducks seen to your local Wyoming Game & Fish Department office. Jackson Nongame Biologist Susan Patla is compiling the data records and will be glad to answer any questions concerning the species.