Effects of laughing gull and shorebird predation on the intertidal fauna at Cape May,New Jersey

The intertidal flats of the Cape May, New Jersey shore of Delaware Bay are populated by large numbers of laughing gulls and migrating shorebirds during the spring and early summer. Exclusion of birds from a shallow slough and a sand bar had only minor effects on the infaunal benthic invertebrate assemblage at either site. The Cape May beaches provide a rich source of food in the form of horseshoe crab (Limulus polyphemus) eggs; foraging on this item may be more profitable than probing the sediment for infauna. Gemma gemma, a small, thick-shelled bivalve, composed over 98% of the benthic infauna at both sites in 1980, and this species may be resistant to predation by certain shorebirds, as suggested by Schneider (1978).