Factors Affecting Piping Plover Productivity on Assateague Island

Abstract

We studied piping plovers (Charadrius melodus) on Assateague Island (Md., Va.) in 1986-87 to estimate population size and to identify factors affecting productivity. Fledging rates (0.19-1.11 chicks/pair) appeared to be lower than the level necessary to maintain a stable population. Fifty-four percent of the nests were unsuccessful. Predators accounted for most (91%) of the known causes of nest losses. Only 1 nest (2.2% of losses with known cause) was lost due to direct human destruction, and we found no evidence that suggested recreational disturbance was a factor affecting productivity. Mean chick fledging success was 69% for broods foraging at bay flats or tidal pools and 19% for broods foraging on ocean beach (P < 0.05). J. WILDL. MANAGE. 55(3):525-531 Piping plovers were listed as threatened throughout their Atlantic coastal breeding range (Newf. to S.C.) in 1986 due to concern about population declines. Declines have been attributed to loss of breeding habitat and poor productivity (U.S. Fish Wildl. Serv. [USFWS] 1988). Factors thought to be contributing to habitat loss include beach development, dune reclamation and beach stabilization, and recreational use (Wilcox 1959, Cairns and McLaren 1980). Low productivity has been attributed to recreational disturbance and high nest predation (Cairns and McLaren 1980, Cairns 1982, Flemming et al. 1988, MacIvor et al. 1990). Nest predation has been linked to nesting habitat characteristics including nesting substrate, amount of vegetative cover, and beach width (Burger 1987, Gaines and Ryan 1988). We studied piping plovers on Assateague Island in Virginia and Maryland. Our objectives were to (1) estimate population size, (2) estimate nest success, (3) examine the influence of habitat characteristics on nest predation, (4) estimate chick survival, and (5) identify factors influencing chick survival. We thank the National Park Service, the Virginia Department of Game and Inland Fisheries, and the Virginia Society of Ornithology for funding. Thanks also go to P. A. Buckley, J. F. Karish, R. B. Rodgers, and K. A. Terwilliger for support. D. F. Stauffer and J. D. Wellman provided criticism.