Table 7. Sex Ratios of Harlequin Ducks on Breeding Streams during pair season in Montana. 



LIFE SPAN AND SURVIVORSHIP 



In Montana, 249 Harlequins (39 adult males, 53 adult females, 157 juveniles) have been 

 banded from 1991 through 1995. Adult males returned to the breeding streams when they had 

 lived during the previous year on 53% (n=51) of occasions, while females returned at a rate of 

 57% (n=81). The higher female rate may be due to the fact that a male may mate with a new 

 female, which could lead him to a new stream, so that he would not be seen on the previous 

 year's stream. For comparison with other studies, 50% of males (n=30) and 55% of females 

 (n=30) returned at least 1 year following marking. Of 40 females marked as adults through 1993, 

 6 had a gap of one breeding season between resightings on the breeding grounds; none marked 

 through 1992 (n=23) had a two season gap. In 5 cases (n=21), males marked as adults had a gap 

 of one breeding season between resightings, and in 1 case (n=9), a two season gap. Of 58 

 juveniles marked in 1992, at least 16 females and 4 males were alive in 1994, and 1 1 females and 



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