Table 6. Harlequin Duck reproductive parameters for 1974-75 (Kuchel 1977) and 1989-1995. 



* includes data from the Rocky Mountain Front (Diamond and Finnegan 1992, 1993) 



* Includes data from Ashley (1994a, 1994b, 1995, pers. comm.) 



Sex ratio. During the spring pair season, a sex ratio of 1 .5 1 : 1 has been observed in 

 Montana (m:f, n =600) (Table 7). Table 7 is based on independent male observations during the 

 period 27 April - 30 May; when more than one survey was done during a single season on a 

 single stream, the survey with the maximum number of females was included in Table 7. 

 Cassirer (1995) found a spring adult sex ratio of 1.31:1 (m:f, n = 81) in 1995 on Idaho streams. 

 In Banff National Park, Alberta, sex ratios varied from 1.37:1 in May to 1.81 in June (Smith 

 1996). In Iceland, sex ratios on the breeding grounds varied from 1.17 - 2.33:1 during 5 

 summers in late May - early June (Bengtson 1966, Bengtson 1972, Gardarsson 1979). 



In coastal British Columbia, the apparent sex ratio is 1.5:1 (544 birds) in winter, declining 

 to 1.4:1 (297 birds) in March- April (Campbell et al. 1990); this grows to 4.3:1 in May, and by 

 July, when adult females are still on the breeding streams, it reaches 18.2:1 (1633 birds). 



17 



