Erwin E. Klaas T. Earl Kaiser Harry M. Ohlendorf 1978 <p> Residues of organochlorine compounds occur commonly in environmental samples and have been associated with adverse effects in numerous avian species (Cooke 1973; L. F. Stickel 1973; W. H. Stickel 1975; Ohlendorf et al. 1977; H. M. Ohlendorf, R. W. Risebrough, and K. Vermeer, unpublished manuscript). The affected species are usually terminal consumers, generally those feeding on aquatic organisms (primarily fish) or birds. </p><p> Brown Pelicans (<i>Pelecanus occidentalis</i>), Double-crested Cormorants <i>(Phalacrocorax auritus)</i>, and certain herons are among the species that have exhibited shell thinning in some regions (see Ohlendorf et al. 1977 for review). In 1972, we began a study to determine: (1) geographic differences in the occurrence of environmental pollutants in Anhingas (<i>Anhinga anhinga</i>) and waders in the eastern United States; (2) differences in environmental pollutant levels among those species nesting at the same localities; and (3) whether eggshell thickness had changed since the widespread use of organochlorine pesticides began in the mid-1940's.</p><p> The wader species included in our study were: Great Blue Heron (<i>Ardea herodias</i>), Green Heron (<i>Butorides virescens</i>), Little Blue Heron (<i>Florida caerulea</i>), Cattle Egret (<i>Bubulcus ibis</i>), Reddish Egret (<i>Dichromanassa rufescens</i>), Great Egret (<i>Casmerodius albus</i>), Snowy Egret (<i>Egretta thula</i>), Louisiana Heron (<i>Hydranassa tricolor</i>), Black-crowned Night Heron (<i>Nycticorax nycticorax</i>), Yellow-crowned Night Heron (<i>Nyctanassa violacea</i>), Least Bittern (<i>Ixobrychus exilis</i>), American Bittern (<i>Botaurus lentiginosus</i>), Wood Stork (<i>Mycteria americana</i>), Glossy Ibis (<i>Plegadis falcinellus</i>), White Ibis (<i>Eudocimus</i> <i>albus</i>), and Roseate Spoonbill (<i>Ajaia</i> <i>ajaja</i>). </p> application/pdf 10.2307/1520919 en Waterbird Society Organochlorine residues and eggshell thinning in anhingas and waders text