pairs/km, with an average of 0.9 pairs /km (Bengtson and Ulfstrand 1971, Bengtson 1972). 



In eastern Siberia (Kistschinsky 1968 /// Bengtson 1972) found 1.1 pairs/km and 0.8 - 1.2 

 broods/km. 



Numbers. Numbers estimated by most recent publications and reports are described in Table 

 4. The largest reported single Harlequin Duck occurrence (see Breeding Range) is from the Bow 

 River drainage in Banff National Park where 215 individuals were calculated to occur during 1995 

 using a mark/resight model (Smith 1996). 



Trends. Little data is available either long or short term. The Atlantic population has 

 undergone and is continuing to undergo significant declines (Harlequin Duck Working Group 

 1993). In the North American Pacific populations, the trend is less clear cut. Christmas bird 

 counts in British Columbia show declines at 5 locations and increases at 3; the increases may be 



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