Abstract
The effects of human activities on shorebirds migrating through Raritan and Delaware Bays (New Jersey, USA) were examined from late April to late October 1982. Less than 5% of the 471,055 shorebirds counted in the censuses were in Raritan Bay, and only eight species accounted for 95% of the total. Bird populations peaked during late May to early June, and had a secondary peak in early August. People walking accounted for 43% (Raritan Bay) and 50% (Delaware Bay) of the disturbances. Other disturbances, in descending order of abundance, were of fishermen, airplanes, dogs, clam-diggers, off-road vehicles, boats, children, and joggers.