swiftly-flowing water. 



3. Absence of human disturbance such as boating, fishing, and residences. 



4. Lack of access by road or trail. 



Lists of some potential breeding streams in the Rocky Mountains based these parameters are contained 

 in Appendices A, B and C, Table 3. 



Productivity 



On average, 12-56% of paired females on a breeding stream successfully produce ducklings 

 to fledging in a given year (Bengtson and Ulfstrand 1971, Kuchel 1977, Wallen 1987, Cassirer and 

 Groves 1991). Duckling survival to fledging ranges from 45-80%. Brood size at fledging averages 2.6 

 - 4.5 (Bengtson 1972, Kuchel 1977, Dzinbal 1982, Wallen 1987, Cassirer and Groves 1991, Reichel 

 and Genter 1995). Recruitment rate is unknown. In an increasing population in Iceland, productivity 

 measured over a 15 year period varied from 0.1 to 3.3 ducklings fledged per hen annually, and 

 averaged 1.1 ducklings per hen per year. (Gardarsson and Einarsson 1991). Productivity is highly 

 variable from year to year and appears to be influenced by magnitude and timing of stream runoff 

 (Kuchel 1977, Cassirer and Groves 1994, Diamond and Finnegan 1993, Reichel and Genter 1994) and 

 food availability (Bengtson and Ulfstrand 1971, Gardarsson and Einarsson 1991). Harlequin ducks 

 feed mainly on benthic invertebrates (Pool 1962, Bengston and Ulfstrand 1971) and roe (Dzinbal 1982) 

 on breeding areas. Lack of productivity is due both to nonb reeding and failed breeding by paired hens 

 (Bengtson and Ulfstrand 1971, Dzinbal 1982, Cassirer and Groves 1991). 



Return rates 



Return rates of banded or nasal-marked adults to breeding streams were 63 % in Idaho (n = 

 31), 40% in Wyoming (n = 54), and 67% in Montana (n = 12, Kuchel 1977)), 57% (n = 30, Reichel 

 and Genter 1995) and 54% (n = 7, Ashley 1994) in Montana. Some ducklings eventually return to 

 their natal streams to breed (Kuchel 1977, Wallen 1991). Return rate of juveniles appears to be low, 

 but is not well documented. At least 5 females of 103 ducklings banded in Grand Teton National Park 

 1987-1990 have returned and nested successfully (Wallen 1991). In Montana, 11 of 67 ducklings 

 banded returned to their natal stream as two-year-olds; all were females and at least 1 nested 

 successfully while 8 did not (Kuchel 1976, Ashley 1994, Reichel and Genter 1995). 



Conservation Genetics 



No information is available on population genetics in harlequin ducks. The extent of genetic 

 variation between the Atlantic and Pacific populations, or across the Pacific breeding range is 

 unknown. Harlequin ducks exhibit a high degree of fidelity to breeding areas, but probably pair on 

 wintering areas where genetic mixing may occur. The degree of similarity among breeding streams is 

 important in understanding both the extent of pair formation and mixing on wintering areas, and the 

 genetic uniqueness of harlequins using different breeding streams or areas. Additional information is 

 needed in order to understand implications for conservation and/or potential reintroduction efforts. 



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