American Oystercatcher winter roosting and foraging ecology at Cape Romain, South Carolina

American Oystercatcher Haematopus palliatus foraging areas, roost sites (diurnal and nocturnal) and prey items were identified. Eight adult oystercatchers were radioed during Dec 2003 to Feb 2004 in Cape Romain Region, one of the most important wintering sites for this species. Mean distance between capture site and two other diurnal high tide roosts was 1,819 m. Distances from mean center of foraging locations to nocturnal roosts were farther than to diurnal roosts. Nocturnal roost sites may contain more birds and be situated farther away from prime feeding areas in order to avoid predation by owls. Oystercatchers spent 53% of the time roosting and only 28% foraging when their feeding areas were exposed at low tide. Prey items were 94% oysters, 4% mussels and 3% unknown prey items. The combination of roost sites (diurnal and nocturnal) and abundant food may explain why the Cape Romain Region has historically and presently had a large concentration of oystercatchers.