Introduction 



Harlequin ducks (Histrionicus histrionicus) are unique sea clucks 

 that winter in coastal areas and migrate inland to nest along swiftly 

 flowing mountain streams. Two distinct populations exist: one in the 

 Atlantic and one in the Pacific. Little information is available 

 concerning harlequin duck migration patterns, breeding biology or 

 habitat requirements (Carlson 1990). Due to the lack of understanding 

 concerning harlequin habitat requirements and increasing 

 encroachment into pristine areas by recreational enthusiasts, the 

 United States Forest Service has listed the harlequin duck as a 

 Sensitive Species (Reel, Schassberger, and Ruediger 1988). 



The Flathead National Forest contracted with the Montana Natural 

 Heritage Program through the Challenge Cost-Share Program to 

 conduct harlequin surveys in 1991. This cooperative agreement has 

 been conducted each summer season since 1988. The objectives of 

 the ongoing harlequin duck project are to collect information on the 

 distribution and population numbers of harlequin ducks in Montana; to 

 identify and describe occupied nesting, brood rearing, and migratory 

 habitats, and to eventually develop a habitat suitability model 

 (Fairman 1990). I began this study on July 15, 1991. My primary goal 

 was to record the distribution and population numbers of harlequin 

 ducks in the non-wilderness portion of the Flathead National Forest. 

 In addition, I identified and described brood rearing sites and 

 collected stream habitat data. This report includes the findings of 

 the 1991 field season. 



