THE EFFECT OF HUMAN DISTURBANCE ON FORAGING BEHAVIOR AND HABITAT USE IN PIPING PLOVER (CHARADRIUS-MELODUS)

Piping plovers breed in coastal areas where they experience intense competition with man. I studied habitat use (using transects) and foraging behavior (using focal animals) at three habitats on each of three nesting beaches over a 2-yr period (1988-1989) in New Jersey, USA, to understand how plovers use space. Piping plovers forage along the tidal oceanfront, in the dunes, and in backbays, and their relative use of these habitats partially depends on the presence of people. Within each habitat the plovers select sites that contain fewer people than the habitat as a whole. The time devoted to vigilance (when they are not searching for food) is directly related to the number of people near them, and to the overall human use of that habitat. Thus, in habitats with few people the plovers can spend 90% of their foraging time actively searching for prey and feeding, whereas on beaches with many people they may spend less than 50% of their foraging time in direct feeding behaviors. A diversity of habitats allows the birds to move between habitats to minimize interactions with people and maximize the time devoted to foraging. The results suggest that it is critical to maintain high habitat diversity in coastal environments to help mitigate competition with people.