Does the group foraging behavior of Double-crested Cormorants increase the proportion of successful dives?

Abstract

The foraging behavior of Double-crested Cormorants (Phalacrocorax auritus) was observed in Les Cheneaux Islands region of the Upper Peninsula in Michigan. Results support the hypothesis that proportion of successful dives significantly increases (p=.036) with increasing flock size. These data suggest that Double-crested Cormorants live in groups for benefits of foraging. The type of interaction which is engaged during foraging, cooperative predation or information parasitism, cannot be determined from this study.