Montana Field Guide

Harlequin Duck - Histrionicus histrionicus

Male larger than female. Alternate plumage of male is unmistakable: Body plumage slate blue; white bands and collars, bordered with black lines, on chest and neck; large white crescent in front of eye; small white circular patch near ear; white vertical stripe along side of neck; black streak, bordered by white and amber lines, on top of head; iridescent blue secondaries; rich dark-slate-blue belly; chestnut-brown flanks. Adult female: brown body plumage; white belly, with brown checks or spots; round white spot behind ear; faded variable white patches in front of eye; and occasionally white streaks on back of head. Juveniles and immatures much like female, but feet tend to yellow, not gray. (Robertson, G. J., and R. I. Goudie. 1999. Harlequin Duck (Histrionicus histrionicus). In The Birds of North America, No. 466 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.)

Montana Range

Harlequin Ducks breeding in Montana arrive primarily from late April to early May (Kuchel 1977, Reichel and Genter 1996). Males depart in June and females and young from late July to early September (Kuchel 1977, Reichel and Genter 1994). Twenty-four birds banded in western Montana have been sighted off of Oregon (2), Washington (1) and southern British Columbia (21) (Ashley 1995, Reichel and Genter 1996).

In Montana, most Harlequin Ducks inhabit fast moving, low gradient, clear mountain streams. Overstory in Montana does not appear to affect habitat use: 1) in Glacier National Park, birds used primarily old-growth or mature forest (90%); and 2) most birds in streams on the Rocky Mountain Front were seen in pole-sized timber (Diamond and Finnegan 1993). Banks are most often covered with a mosaic of trees and shrubs, but the only significant positive correlation is with overhanging vegetation (Diamond and Finnegan 1993, Ashley 1994).

The strongest stream section factor in Montana appears to be for stream reaches with 2+ loafing sites per 10 m (Kuchel 1977, Diamond and Finnegan 1993, Ashley 1994). Broods may preferentially use backwater areas, especially shortly after hatching (Kuchel 1977), though this is not apparent in data from other studies (Ashley 1994). Stream width ranges from 3 m to 35 m in Montana. On stream gradients of 7%, occupied stream reaches ranged from 1.8% to 2.8% (Fairman and Miller 1990), while velocity at 42 Harlequin observation points ranged from 0.8-4.1 m per second (Diamond and Finnegan 1993). Harlequins in Glacier National Park used straight, curved, meandering, and braided stream reaches in proportion to their availability, as was the case for bottom types (Ashley 1994).

No nest sites have been reported from Montana; in the Pacific northwest, nests have been reported on rocks (3); on the ground (2); in a cliff face (1); (Bent 1925, Campbell et al. 1990); in piles of woody debris (2) (Jewett 1931, Thompson 1985); in tree cavities (2); and in a cavity on a cliff (1) (Cassirer et al. 1993).

95% of the material in droppings in Grand Teton National Park consisted of Stoneflies, Mayflies, and Caddisflies (Wallen 1987).

In Montana, adult males returned to the breeding streams from the previous year 53% of the time, while females returned at a rate of 57% (Reichel and Genter 1996). Of 58 juveniles marked in 1992, at least 12 females and 2 males were alive in 1994 (Reichel and Genter 1996). All females known to be alive have returned to their natal streams, while no males have (Reichel and Genter 1996). Nearly all mortality of ducklings (through fledging) apparently takes place during the first 3 weeks following hatching (Kuchel 1977). In Idaho, the spring adult male:female ratio is 1.31:1 (n=81) (Cassirer 1995).

Densities of Harlequins in Montana range from 0.05-0.21 pairs per km on the Rocky Mountain Front to 0.67-0.91 pairs per km on McDonald Creek (Kuchel 1977). Linear home ranges averaged 7.7 km on McDonald Creek (Cassirer and Groves 1992 reanalysis of Kuchel 1977). Four relatively long distance movements between streams, across large reservoirs or lakes, have been reported in Montana ranging from 16 to 31 km (Reichel and Genter 1996).

In Montana, egg-laying takes place between April 30 and July 4 with most between May 10 and June 10; it tends to be during the earlier dates on the lower Clark Fork River tributaries and during the later dates on the streams north of Yellowstone National Park (Kuchel 1977, Reichel and Genter 1996). Kuchel (1977) estimated hatching dates for broods on McDonald Creek, Glacier National Park: 13 of 15 occurred between June 27 and July 7 with extremes on June 11 and August 2. Young fledge in Montana between July 15 and September 10, with most fledging between July 25 and August 15 (Kuchel 1977, Reichel and Genter 1996).

In Montana, no males have been reported on breeding streams prior to attaining fully adult plumage at 3-years of age (Phillips 1986, Reichel and Genter 1996). The youngest female known to have bred is a single 2-year-old, although 9 additional 2-year-olds have been observed on natal streams and 13 marked 2-year-olds are known to have been alive (Reichel and Genter 1996).

In Montana during 1989 to 1994, annual numbers of ducklings fledged per adult female averaged 1.60 and ranged from 0.84 to 3.15 (n=230 adult females) (Reichel and Genter 1995). Brood size of Class 1-IIb young (Bellrose 1976) averaged 5.1 on the Rocky Mountain Front (Diamond and Finnegan 1993), while throughout Montana, size IIc to fledging averaged 3.57 and ranged from 2.81 to 5.86 (n=103) (Diamond and Finnegan 1993, Reichel and Genter 1995). It should be noted that Harequins have essentially no chance to renest because males leave the breeding streams to return to the ocean soon after incubation begins.

The proportion of females successfully raising a brood varies widely between years. In Montana, 230 females observed between 1989 and 1994 raised 103 broods for an average of 44.8% and ranged from 24% to 55% (Reichel and Genter 1995). High summer runoff has been associated with low productivity (Kuchel 1977, Diamond and Finnegan 1992, 1993, Reichel and Genter 1993, 1995).