SEASONAL NUMBERS AND DISTRIBUTION OF SHOREBIRDS ON NORTH-CAROLINA OUTER BANKS

We documented the seasonal abundance, distribution, and relative impor tance of outer beach habitats to shorebirds on the Outer Banks of Nort h Carolina. The Outer Banks span 228 km and attract millions of touris ts every year, underscoring the need for baseline data for conservatio n. Twenty-one species were recorded during the study. The most abundan t were Sanderling (Calidris alba), Red Knot (Calidris canutus), and Wi llet (Catoptrophorus semipalmatus). As an assemblage, shorebirds were most abundant in May and August. Peak numbers for each species were re corded between April-May and July-September. The greatest numbers were recorded on North Beach and the lowest on South Beach (1992) and Bodi e Island (1993). Shorebird abundance was greater during fall (68 birds /km) than in spring (50 birds/km). Patterns of abundance of the eight most abundant species were examined in detail. Black-bellied Plovers ( Pluvialis squatarola), Willets, Whimbrels (Numenius phaeopus), Ruddy T urnstones (Arenaria interpres) and Sanderlings were most abundant on N orth Beach. North Core Banks harbored the highest numbers of Piping Pl overs (Charadrius melodus), American Oystercatchers (Haematopus pallia tus), and Red Knots. American Oystercatchers and Whimbrels were signif icantly more abundant during spring than fall, whereas Willet and Sand erlings were more abundant during fall. The Outer Banks emerged as an important staging area for the Atlantic populations of Piping Plovers, Whimbrels, and Sanderlings when compared to 7 other areas along the e astern U.S. coast. The importance of the area to Sanderlings was reaff irmed by return rates of 58%, most (69-89%) returning to the beach str etch where they were banded. The area gains special significance becau se it also supports a nesting population of Piping Plovers. Our findin gs confirm that the Outer Banks of North Carolina provide a critical l ink in the migratory path of several shorebird species. Habitat loss o r alteration could adversely affect the Atlantic Flyway population of several species (e.g., Sanderlings) as well as the threatened Piping P lover.