they were once relatively common. Reductions in the Pacific breeding distribution have been 

 documented primarily in the eastern and southern parts of the range (Cassirer et al. 1993). Harlequin 

 ducks appear to no longer use at least 10 streams in the Rocky Mountains which previously (as recently 

 as 1987) had a record of use (Table 5) . However, pair numbers on most breeding streams that have 

 been surveyed for 3 or more years appear to be stable (Appendix D). 



Table 4. Estimated United States harlequin duck breeding population in the Pacific Northwest 

 and Rocky Mountains (Cassirer et al. 1993, Thompson et al. 1993). 



State 



Washington 



Oregon 



Idaho 



Montana 



Wyoming 



Total 



523 



287 



Maximum number observed during surveys. 



Assuming 69% observability under optimum survey conditions (Cassirer and Groves 1994). Data not available outside 



the Rocky Mountains. 



Table 5. Rocky Mountain streams previously used by harlequin ducks where no use has been 

 documented since 1988. Number in parentheses is number of surveys 1989 - 1994. 



State Historical consistent use 



documented 



Idaho 



Montana 



Wyoming 



Historical occasional Historical occasional pair 



hrerAmp d ornmented use documented 



Kelly Creek and N. Fork 

 Clearwater River below Kelly 

 Creek (3) 1 



Kootenai Falls area of Kootenai 

 River (11)' 



Smith Creek 

 (Kootenai River) (3) 1 



Otatso Creek 



Orogrande Creek (N. Fork 

 Clearwater River) (4) 1 



Bighorn River Canyon 

 Jocko River 

 Sweet Water Creek 



Shell Creek Canyon 



8 



