and departure dates vary with local populations. This variation 

 may be attributed to timing of spring runoff, differences in 

 elevations, timing of phenology of stream side vegetation, or for 

 other reasons unknown to us at this time (Kuchel 1977, Wallen 

 1987) . 



Harlequin ducklings are capable of flight at approximately 

 6 weeks old. Shortly thereafter, they begin to depart for 

 Pacific coast waters (Kuchel 1977, Wallen 1987, Wallen and Groves 

 1988) . 



Habitat Use 



Harlequin ducks, unlike most other ducks, inhabit swift 

 flowing, often treacherous mountain streams. Harlequins studied 

 in the Rocky Mountain region feed primarily on aquatic benthic 

 insects such as caddisflies and stoneflies (Wallen 1987, Kuchel 

 1977) . In Iceland and Alaska, salmon roe comprise a significant 

 portion of the duck's food base (Bengston 1966, Dzinbal 1982). 

 Based on the studies completed to date in the Rocky Mountain 

 region (Wallen 1987, Kuchel 1977, Wallen and Groves 1988, 1989) 

 harlequin summer habitat is described as containing: 



1. a stream with high water quality and a healthy 

 population of aquatic insects. 



2. a low gradient perennial stream with areas of swift 

 water. 



3. stream side cover, usually comprised of moderate to 

 dense shrubs. 



