INTRODUCTION 



The harlequin duck ( Histrionicus histrionicus ) is a member 

 of the tribe Mergini (sea ducks) and as such is taxonomically 

 related to the eiders (Somateria sp. and Polysticta stelleri ) , 

 scoters (Melanitta) , and oldsquaw ( Clanqula hyemalis ) (Johnsgard 

 1978) . However, because of their preference for isolated, swift- 

 flowing mountain streams as breeding habitat, harlequin ducks 

 appear to be more similar ecologically to the torrent duck 

 ( Merqanetta armata ) of South America and the blue duck 

 ( Hymenolaimus malachorhynchos ) of New Zealand (Bengston 1966) . 



The distribution of the harlequin duck is divided into 

 distinct eastern and western populations (Figure 1) (Bellrose 

 1980) . The relatively small eastern population extends across 

 northeastern North Tunerica, Greenland, and Labrador, reaching its 

 Uhighest density in Iceland (Bengston 1966) . The western 

 population is found near the west coast of North America from 

 northern California to Alaska, with the greatest numbers 

 occurring in the Aleutian Islands; a small number also may be 

 found along the coast of the Siberian peninsula (Bellrose 1980) . 



Throughout their range harlequin ducks tend to winter on 

 rocky wave-pounded ocean coasts and breed on isolated swift- 

 flowing mountain streams (Bengston 1966, Johnsgard 1978). The 

 majority of the western population winters on the Aleutian Island 

 National Wildlife Refuge where up to one million harlequins may 

 be found (Bellrose 1980) . Further south, Christmas bird counts 

 have found only 500 birds along the coast of British Columbia and 



