Evidence of High Tolerance to Ecologically Relevant Lead Shot Pellet Exposures by an Upland Bird

ABSTRACT Upland birds that display grit ingestion behavior are potentially at risk of detrimental effects and death from lead poisoning at trap and skeet ranges and other areas where vast quantities of spent lead shot pellets abound. Because commonly cited force-feeding pellet exposure studies deviate from true field conditions, their results may not reflect true risks faced by upland birds. In particular, studies that use new shot pellets and administer more pellets than would be reasonably ingested, critically interfere with the understanding of actualized pellet exposures. In this study, northern bobwhites (Colinus virginianus), a frequent test species in shot pellet research, were dosed in an ecologically-relevant manner (i.e., with spent shot and with no more than three pellets). Notably, the 56-day post-dosing observation period, during which a battery of physiological measures were recorded, exceeded that of related studies. Despite a sustained suppression of a lead poisoning indicator, the data su...