Aggregative response of Harlequin Ducks to herring spawning in the Strait of Georgia, British Columbia.

Focuses on the scale of aggregative response of Harlequin Ducks to seasonally and locally superabundant prey at Pacifi herring spawning sites in the northern Strait of Georgia, British Columbia during 1995-2002. Average duration of stay at spawning sites; Percentage of the total population moving to spawning sites.