METHODS AND MATERIALS 



All literature and reports in the Bibliography section were reviewed and evaluated. Contacts were 

 made with members of Harlequin Duck Working Group and other knowledgeable individuals to 

 determine current research projects and their applicability to sections in this report. 



DISTRIBUTION 



NORTH AMERICA 



Breeding range Figure 1,2,3. Breeds in two disjunct regions in North America. The 

 Pacific population breeds from western Alaska, northern Yukon, northern British Columbia, and 

 southern Alberta south to Oregon, Idaho, Wyoming, and east of the Continental Divide in 

 Montana. The Atlantic population breeds from Baffm Island (at least formerly) through central 

 and eastern Quebec, eastern Labrador, and northern Newfoundland. Occurs in summer in 

 Mackenzie Valley and near Great Slave Lake, Northwest Territories (Amencan Ornithologists 

 Union 1983, Harlequin Duck Working Group 1993, 1994). 



In the Rocky Mountains of the United States, Harlequins currently breed in western Montana 

 (Reichel and Center 1995), northern and southeastern Idaho (Cassirer and Groves 1994), and 

 northwestern Wyoming (Wallen 1993, McEneaney 1994). Distribution within the area is shown 

 in Figure 2. While much of Montana and Idaho has been surveyed (Figure 3), some areas with 

 potential habitat have yet to be completed; surveying m Wyoming is less complete. As of 1995, 

 surveys have been conducted on approximately 5,640 km of streams (Montana - 2,963 km, Idaho 

 - 1,886 km; Wyoming 792 km) (Cassirer et al. 1996). Using habitat characteristics, accessibility, 

 amount of human use, and nearby Harlequin Duck occurrences, streams were identified that had 

 the highest potential for Harlequin Duck occurrence, for which no ducks had been observed; these 

 included 31 in Montana, 16 in Idaho, and 41 in Wyoming (Cassirer et al. 1996). 



In the literature and in unpublished reports. Harlequins within a geographical area often listed 

 as "breeding on XX number of streams." This has been used differently by various authors to 

 mean: 1) every named stream, 2) larger named streams; and 3) the major stream in an occupied 

 drainage. Recently, biologists in Montana, Idaho, and Wyoming have written and adopted the 

 standard Heritage Program definition of an "element occurrence (EO):" A drainage/portion of a 

 drainage used by Harlequins where breeding is known or highly suspected (3 or more independent 

 observations of females or pairs). The EO contains contiguous stream reaches used (and portions 

 of lakes, reservoirs or bays, if regularly used) during the courtship, nesting, and brood-rearing 

 periods, and not separated by more than 10 km of unsuitable habitat or 20 km of unoccupied 

 habitat. 



The breeding status on many streams with Harlequin Duck sightings has not been established 

 in the Rocky Mountains of Montana, Idaho, and Wyoming. In Montana, there are currently 33 

 Harlequin Duck EOs and 32 streams where Harlequin Ducks have been observed or reported but 

 on which the breeding status is unknown; these streams have been surveyed 0-5 times each 

 (Cassirer et al. 1996). In Idaho, there are currently 16 Harlequin Duck EOs and 24 streams 

 where Harlequin Ducks have been observed or reported but on which the breeding status is 

 unknown; these streams have been surveyed 0-5 times each (Cassirer et al. 1996). In Wyoming, 

 there are currently 8 Harlequin Duck EOs and 1 7 streams where Harlequin Ducks have been 



