Abstract
The behaviour of nesting and loafing herring gulls
Larus argentatus was compared when the birds were exposed to supersonic transport, subsonic aircraft and normal colony noises at Jamaica Bay National Recreational Area. No effects of subsonic aircraft on nesting gulls were noted. However, when supersonic transports flew over, significantly more nesting gulls flew from their nests, and they engaged in more fights when they landed compared with the other conditions. Many eggs were broken during these fights, and subsequently eggs were eaten by intruders. At the end of the incubation period there were lower mean clutch sizes in dense sections (more potential for fights) of the colony compared with solitary nesting pairs of gulls. For loafing gulls, significantly more birds flushed when planes flew over compared with immediately before and after such plane noises.