Abstract
The distribution and abundance of gulls were examined on Raritan and Delaware Bays from 20 April to 26 October 1982. Gull numbers were affected by seasonal, tidal, weather-related, and human disturbance, factors on both Bays. Gulls comprised from about 40 to 60% of the avifauna on the census areas, and shorebirds accounted for most of the other individuals. Peak numbers of gulls were present on Delaware Bay from May through July, and on Raritan Bay in September. Laughing Gulls (Larus atricilla) were the dominant species on both Raritan (90%) and Delaware (70%) Bays, with Herring Gulls (L. argentatus) second in abundance.