INTRODUCTION 



In the Rocky Mountain region, Harlequin Ducks (Histrionicus 

 histrionicus) are known to occur as rare and local breeders from 

 northwestern Wyoming to British Columbia and Alberta. Western 

 Montana is near the eastern limit of their breeding range, and 

 according to Kuchel (1977) , breeding populations are uncommon and 

 localized in this region. The western populations of harlequins 

 winter along the north Pacific coast on rocky seashores from the 

 Aleutian Islands to central California (Kuchel 1977) . A few 

 individuals marked in northwest Wyoming and northern Idaho have 

 been sighted near the San Juan Islands off Washington's northern 

 coast (Cassirer and Wallen, unpubl . data) . 



Harlequins return in March and April to inland breeding 

 sites, which are usually located on fast moving, low gradient 

 mountain streams with high water quality and dense vegetation 

 (Wallen and Groves 1989) . Although some streams appear to be 

 ideal harlequin habitat, human disturbance and precise ecological 

 requirements severely restrict harlequins' breeding range (Kuchel 

 1977) . After mating, males return to the Pacific coast (late May 

 - early July) and are followed by females and their broods in 



