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Many lead exposure studies of scavenging birds have focused on individual species. However, studying multiple species with similar, but not identical, feeding behaviors can provide insights into how an animal’s ecology determines its lead exposure. 

To identify lead exposure patterns in species with different feeding ecology, researchers analyzed lead concentrations in blood and livers of facultative American crows, bald eagles, golden eagles, red-shouldered hawks, red-tailed hawks and obligate scavengers black vultures and turkey vultures. The degree to which these species scavenge determined the degree to which they were lead-exposed; obligate scavengers had higher lead concentrations than did facultative scavengers. Facultative scavengers had higher lead concentrations in autumn and winter than in spring and summer, presumably because birds’ diet switched from consuming live prey to consuming dead prey that may be contaminated with lead fragments. Findings highlight the importance of dietary and behavioral variation in determining lead exposure.

Slabe, V.A., Anderson, J.T., Cooper, J.L., Miller, T.A., Brown, B., Wrona, A., Ortiz, P.A., Buchweitz, J., McRuer, D., Dominguez-Villegas, E., Behmke, S., Katzner, T.E., 2020, Foraging ecology drives lead exposure of facultative and obligate avian scavengers in eastern North America: Environmental Toxicology,

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