Displacement of a large double-crested Cormorant, Phalacrocorax auritus, colony following human disturbance

Abstract

Double-crested Cormorants (Phalacrocorax auritus) breeding at a Prince Edward Island colony, the largest in northeastern North America, shifted their nesting location to a nearby island after springtime shooting at the colony. Post-shift numbers at the new site (4525 nests) were 92% of the previous combined population of the two colonies. Clutch size and hatching date were similar before and after the move. Disturbance-induced displacements of seabird colonies are rare; this shift may have been caused by perturbation during a sensitive period prior to laying.