that the survey effort as presented in this report was very 

 thorough, this report does not provide positive proof for the 

 absence of harlequin ducks in the streams examined. However, if 

 populations exist on streams beside the Boulder River they are 

 likely to be very small and transitory. 



The Stillwater and Boulder drainages may be at the eastern 

 edge of harlequin range in Montana. Because so little is known of 

 the habitat requirements and limits of breeding harlequin ducks 

 it is difficult to say with certainty that suitable habitat does 

 exist in these areas in any great amount. Determining the habitat 

 requirements of harlequin ducks continues to be the most pressing 

 need for proper management of this species on its breeding 

 grounds. 



Additional survey work in this area will be dependent on the 

 informational needs of the management agencies. Increasing human 

 activity along streams and the potential for water quality 

 degradation from a variety of sources are probably the main 

 impacts facing harlequin duck habitat in southwestern Montana. 

 Additional study on the biology and habitat needs of harlequin 

 ducks would be more fruitful in areas with higher harlequin 

 densities. 



LITERATURE CITED 



Bellrose, F.C. 1980. Ducks, geese, and swans of North America. 

 Stackpole Books, Harrisburg, PA. 54 0pp. 



Bengston, S.A. 1966. Field studies of the harlequin duck in 

 Iceland. Wildfowl Trust Ann. Rep. 17:79-94. 



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