Effects of oiling on feeding behavior of sanderlings and semipalmated plovers in New Jersey

I examined the foraging behavior of Sanderlings (Calidris alba) and Semipalmated Plovers (Charadrius semipalmatus) during their spring stopover period along the Atlantic coast of southern New Jersey following an oil spill. I used focal animal sampling to test the null hypothesis that there are no differences in foraging behavior as a function of the degree of oiling of birds. Nearly 50% of the foraging time of shorebirds was interrupted during the main period of beach oiling, primarily by clean-up personnel and vehicles that moved up and down the oiled beach, compared to less than 5% of the foraging time disruption at a control beach where birds were interrupted only by walkers and joggers. For both species, the time devoted to feeding decreased significantly, whereas the time devoted to standing about and preening increased significantly as percent of oiled plumage increased. For shorebirds that are already time-stressed in their refueling efforts before their long journey to arctic breeding grounds, these interruptions may prove fatal or might lower reproductive success once they reach the breeding grounds.