Nest Spacing, Reproductive Success, and Behavior of the Great Black-Backed Gull (Larus marinus)

A study of the relationship of nest spacing, reproductive success, and behavior of the Great Black-backed Gull (Larus marinus) was conducted during the 1979 breeding season.Egg production and hatching success were similar on territories in high and low density areas, but gulls in high density areas fledged significantly fewer chicks than those in low density areas.Adults breeding in high density areas engaged in significantly more bouts of agonistic interactions and chick-oriented vocalizations than pairs in low density areas, although there were no significant differences between the two groups in the frequency of long calls, choking bouts, or chick feedings.The results of this investigation are related to a model proposed by Hunt and Hunt (1976) that predicts that, in the absence of interspecific predation, larger territories may confer a reproductive advantage on some larids due to a decrease in conspecific interference.