Foraging patterns of male and female DoublecrestedCormorants nesting in the Columbia Riverestuary

Double-crested Cormorant (Phalacrocorax auritus) Science Article 17


The nesting colony of Double-crested Cormorants, Phalacrocorax auritus (Lesson, 1831), on East Sand Island in the Columbia River estuary is currently the largest for this species on the Pacific Coast of North America. We used radiotelemetry to investigate the spatial and temporal foraging patterns of nesting cormorants to better understand how this colony of piscivores meets its resource needs. We determined that nesting adults tended to forage >5 km from the colony and foraging distribution was distinctly different between the sexes. On average, males commuted nearly twice the distance to forage compared with females.

Cynthia D. Anderson, Daniel D. Roby, and Ken Collis, Can. J. Zool. 82: 541-554 (2004)

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