ENVIRONMENTAL CONTAMINANT LEVELS IN SHARP-SHINNED HAWKS FROM THE EASTERN UNITED-STATES

We examined contaminant levels in tissue samples of sharp-shinned hawk s (Accipiter striatus) collected in the eastern U.S. from 1991-93. We report concentrations of aldrin, cis-nonachlor, p,p'-DDE, dieldrin, he ptachlor epoxide, mirex, oxychlordane, PCB, aluminum, lead, and mercur y detected in 23 blood, 10 brain, and 31 liver samples. DDE, PCB's, an d mercury were detected most often and in highest concentrations. No c ontaminants were present at concentrations that might cause mortality with the possible excep tion of one individual with high oxychlordane residues in the liver. It is not known, however, at what levels these contaminants might impair reproduction in sharg-shinned hawks. Migrati on count data (declining sharp-shinned hawk numbers in the East, stabl e in the Midwest) coupled with contaminant data (higher DDE levels in blood in eastern sharp-shins than in midwestern) do not rule out the p ossibility that contaminants may be impairing reproduction in the east ern population, although our data suggest that this is unlikely. Furth er study of contaminant levels in sharp-shinned hawks with concurrent research on their productivity and on prey availability is necessary. This species also may be an important indicator species for monitoring contaminant levels because of their high position in the food chain.