Mercury Occurrence in Prothonotary Warblers (Protonotaria citrea) Inhabiting a National Priorities List Site and Reference Areas in Southern Alabama

Abstract

Mercury occurrence in prothonotary warblers (Protonotaria citrea) was evaluated over two years in southern Alabama. Mercury was found in warbler nestlings and adults inhabiting National Priority List (NPL) sites in McIntosh, Alabama. Food items that were collected from nestlings also contained elevated mercury. When mercury concentrations in soil, food, and nestling were plotted at each nest box location, the distribution of mercury in the three matrices yielded information that direct bioaccumulation factors could not. There were site differences in mercury accumulation in nestlings inhabiting the NPL sites. Nestling mercury accumulation correlated with solid mercury concentrations near the nest box where the nestling was raised. Trophic transport of mercury was poorly defined by mercury in food; however, closer examination of prey items shows that food source influences accumulation. Mercury distributions in matrices provide useful information of uptake that can be integrated with risk assessment endpoints.