Harlequin ducks have a unique migratory pattern. They 

 migrate inland to breed and nest in mountainous streams, and 

 return to the ocean upon completion of the breeding cycle. 



Breeding habitat for harlequin ducks in Idaho has been found 

 to be fast running low gradient mountain streams with banks 

 covered by dense shrubs (Wallen & Groves 1989) . Kuchel (1977) 

 found that adult harlequin ducks on McDonald Creek in Glacier 

 National Park, Montana confined almost all their activity to 

 swiftly running waters, but also used stretches of abandoned 

 stream channel. 



Harlequin ducks spend 2 to 5 months on breeding streams in 

 Montana. Pairs arrive in late April or early May. Pair 

 formation is apparently completed by the time they leave the 

 coast, and males appear to defend a moving territory around the 

 female (Bellrose 1976) . Nesting begins in late May (Kuchel 

 1977) . Eggs are laid at an interval of 2 to 4 days with an 

 average clutch size of 5.5; females incubate for 28 days 

 (Bengston 1966 and 1972) . Males depart mid- to late June for the 

 coast with females and broods joining males in late August and 

 early September (Kuchel 1977, Miller 1989). Harlequin ducks do 

 not breed until they are 2 years old (Bellrose 1976, Palmer 

 1976) . 



Studies of harlequin duck food habits indicate harlequins 

 feed almost entirely on animal matter. Cottam (1939) found 

 animals represented 98% of the food consumed. Benthic insects 

 are the main food consumed while the ducks are on the breeding 



