Although birds are a conspicuous element in estuarine ecosystems, annual fluctuations in the size and structure of avian salt marsh communities have not been studied extensively. From October 1978 through October 1980, we censused an avian community inhabiting a 3000-hectare estuary in SC using 4 censusing techniques: bi-monthly aerial surveys, airboat surveys, ground counts at communal roosts, and almost daily spot checks through the marsh for transient species. Avian density averaged 2.6 birds/hectare and avian biomass averaged .7 Kg/hectare annually. Ninety-five species of birds from 12 avian orders fed on the marsh during the 2-year period. Over one-third of the species were members of the order Charadriiformes. Species counts were greatest in spring and fall during migration and lowest in winter and summer. Similar peaks and troughs occurred in biomass and in number of birds sighted. Migrating passerines, mostly swallows, comprised a significant portion of the population in early fall and wading birds comprised a significant portion of the avian biomass in the early part of the breeding season as well as during the late summer when large number of White Ibis fed on the marsh. Clapper Rails and shorebirds, especially dowitchers, dominated the avian community throughout most of the year.