Identifying sources of Pb exposure in waterbirds and effects on porphyrin metabolism using noninvasive fecal sampling

Waterbird feces (mainly mallard Anas platyrhynchos and coot Fulica atra) were collected from four wetlands in Southern Spain in the field or during capture (n = 558 and n = 59, respectively) to study lead (Pb) shot ingestion. Lead and aluminum (Al) concentrations along with Pb isotope signatures were used to identify sources of Pb exposure. The profile and concentrations of porphyrins and biliverdin in feces were used as biomarkers of toxicological effects. Feces with Pb concentrations ¿ 34 ¿g/g d.w. showed higher Pb/Al ratios, together with lower (206)Pb/(207)Pb and (208)Pb/(207)Pb ratios, and higher (208)Pb/(206)Pb ratios, than feces with