INTRODUCTION 



The Harlequin Duck {Histhonicus histrionicus) is a small sea duck, which travels inland to 

 breed on fresh water streams. Harlequins breed in western North America from Alaska and the 

 Yukon south through western Montana to California (Harlequin Duck Working Group 1993); in 

 eastern North America, they breed from Baffm Island south to eastern Quebec and Labrador 

 (Goudie 1993). In the Palaearctic, they breed in Iceland, Greenland and Siberia (A.O.U. 1983). 

 Approximately 1 10-150 pairs of Harlequins currently breed in Montana (Reichel and Genter 

 1994), with most located in the following areas: 1) tributaries of the lower Clark Fork River; 2) 

 tributaries of the North, Middle, and South Forks of the Flathead River; 3) streams coming off the 

 east front of the Rocky Mountains; and 4) the Boulder River (Miller 1988, 1989, Kerr 1989, 

 Carlson 1990, Fairman and Miller 1990, Diamond and Finnegan 1992, 1993). 



During the breeding season. Harlequins are found along fast mountain streams (Bengtson 

 1966). In many areas. Harlequins use streams with dense timber or shrubs on the banks (Cassirer 

 and Groves 1990), but they are also found in relatively open streams along the east slopes of the 

 Rocky Mountains, Montana (Markum and Genter 1990, Diamond and Finnegan 1992), and the 

 Arctic tundra (Bengtson 1972). In Idaho, 90% of observations occurred near old growth or 

 mature timber stands (Cassirer and Groves 1990). Mid-stream rocks, logs, islands, or stream-side 

 gravel bars serve as safe loafing sites and appear to be important habitat components. 



Most of the ducks arrive on their inland breeding areas in mid- April to early-May; unmated 

 males typically arrive before pairs (Kuchel 1977). The males return to the coast shortly after the 

 females begin incubation; most are gone by early July (Kuchel 1977). The females and young 

 remain on the streams until August or early September. This chronology is influenced by 

 elevation and by the timing of spring runoff; it may vary up to several weeks between years. 



The U.S. Forest Service, Region 1, lists the Harlequin Duck as Sensitive (Reel et al 1989). 

 The species is listed as a Species of Special Concern by the Montana (Montana Natural Heritage 

 Program 1994) and Idaho (Idaho Conservation Data Center 1994) Natural Heritage Programs. 

 The eastern North American population is listed as Endangered in Canada (Goudie 1993); the 

 eastern and western populations are both listed under Category 2 as candidates for protection 

 under the Endangered Species Act by the U.S. Fish and Wildlife Service (U.S. Department of 

 Interior 1991). 



The Montana Natural Heritage Program began surveying Harlequin Ducks in 1988. The 

 survey data gave rise to questions involving site fidelity, productivity and mortality. We began 

 individually marking Harlequins to a limited extent in 1991; through 1995, a total of 249 

 Harlequins were marked on 9 streams, representing the largest population of marked Harlequins 

 from breeding streams. Birds marked in Montana have subsequently been captured and observed 

 on the coasts of Oregon, Washington and British Columbia, with most reports coming from 

 Vancouver Island. During that time, we observed 20 previously marked adults returning to 

 Montana streams. 



