Sources of Lead in Red-Shouldered Hawks

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One of the most common pathways of lead exposure in birds is ingestion of contaminated food sources.

Most studies of lead exposure of raptors focus on the winter, non-breeding season when they scavenge heavily. However, less is known about lead exposure of these species during the breeding season when their diets consist almost exclusively of live prey. Researchers found elevated blood lead concentrations of some red-shouldered hawks during the non-scavenging season in the eastern United States. Fifty-three of 70 hawks were above the limit of detection. Adult hawks had higher lead levels than did nestlings. There were no differences in blood lead concentrations in hawks in three different regions of Virginia, but hawks from urban areas had higher blood lead concentrations than those from rural areas. This study illustrates that red-shouldered hawks are exposed to lead when not scavenging, and suggests pathways by which these birds may be exposed. Accompanying image courtesy Sharon E. Avila. 

 

Slabe, V.A., Anderson, J.T., Cooper, J.L., Ortiz, P.A., Wrona, A., Jensen, M.K., Buchweitz, J., Katzner, T.E., 2019, Lead exposure of red-shouldered hawks during the breeding season in the central Appalachians, USA: Bulletin of Environmental Contamination and Toxicology, https://doi.org/10.1007/s00128-019-02732-9