W. James Fleming Keren L. Ensor Donald H. White 1988 <p>Waterfowl wintering on the Yazoo National Wildlife Refuge (NWR) were contaminated (ltoreq 4 ppm wet wt) with dichloro diphenyl trichloroethane (DDT) and 1,1-dichloro-2,2-bis-(p-chlorophenyl) ethylene (DDE), but residues were below levels known to affect waterfowl. Eggs of some nesting waterbirds contained higher than expected levels of DDE, especially those of green-backed herons (<i>Butorides striatus</i>), ranging up to 43 ppm wet weight. Hatching success (P &lt; 0.05) and eggshell thickness (P &lt; 0.05) in green-backed herons and anhingas (<i>Anhinga anhinga</i>) were negatively correlated with DDE in the eggs, and shell thinning (P &lt; 0.05) was evident 12-13 years after DDT was banned in the United States. The threshold level of DDE determined necessary for reduced hatching success in green-backed heron eggs was 5.1-10 ppm wet weight. These results further increase our ability to interpret DDE concentrations in waterbirds and predict their potential effects on productivity.</p> application/pdf 10.2307/3800937 en Wiley Pesticide contamination and hatching success of waterbirds in Mississippi article