SUMMARY 



This report presents findings of a 1990 field survey for 

 harlequin ducks ( Histrionicus histrionicus ) in northwest and 

 west-central Montana. A brief overview of the natural history 

 and habitat requirements of harlequin ducks is included. 



A total of 45 streams, 37 on the Kootenai National Forest 

 (KNF) and 8 on the Lolo National Forest (LNF) , were surveyed 

 between May 5, 1990 and August 31, 1990. Harlequin ducks were 

 observed on 39 occasions. A minimum of 27 individuals were 

 identified. Of the 27 individuals, 6 were males, 7 females and 

 14 juveniles. The harlequins were located on 7 streams on the 

 KNF: Big Creek, Callahan Creek, Grave Creek, Kootenai River, 

 Marten Creek, Swamp Creek, and the Vermilion River. Harlequins 

 were located on 1 creek on the LNF: Trout Creek. Broods were 

 located on Big Creek, Callahan Creek, Marten Creek and two on 

 Vermilion River, for a total of 5 broods. The sightings on 

 Callahan and Big Creeks are the first confirmed sightings of 

 breeding harlequins on those streams. Brood size of the 5 broods 

 ranged from 1 to 3 individuals with a mean of 2.3. Hatching was 

 estimated to occur mid-late June. Harlequins were found on 

 streams ranging 5 m to over 30 m wide. Stream flows ranged from 

 24 cfs to >4000 cfs. Stream gradients were between 1.8 % and 

 2.8 %. Harlequins were found in assortment of habitats. Common 

 to all the occupied streams was the presence of beaver activity, 

 stream braiding or multiple channels, moderate to dense stream 

 side vegetation, and a flyway above the stream mostly clear of 

 overhanging vegetation. A decrease in duck numbers and brood 

 size was observed compared to 1989. It is unclear if the 

 decrease reflects a downward population trend, a normal 

 fluctuation in the population, or is a function of survey 

 methods . 



