LEAD POISONING IN THE GLOBALLY THREATENED MARBLED TEAL AND

Abstract—Marbled teal (Marmaronetta angustirostris) and white-headed duck (Oxyura leucocephala) are the two European ducks threatened with global extinction. We investigated lead (Pb) poisoning in stifftails (Oxyura spp., n 5 83) and marbled teal (n 5 80) shot or found dead or moribund in Spanish wetlands via gizzard examination and liver, bone, and blood Pb analysis. Ingested Pb shot was present in 32 % of shot stifftails and 70 and 43 % of dead or moribund stifftails and marbled teal, respectively. Lead-shot ingestion was more frequent in Valencia (eastern Spain), where Pb-shot densities were higher and grit scarcer. Selection of larger grit similar in size to Pb shot may explain the higher rate of Pb-shot ingestion observed in stifftails. Ingested shot was found more frequently in juvenile stifftails than in adults. Lead bone concentrations were higher in ducklings,9 d old than in fully grown teal and were also higher in adult than in juvenile teal. Our results show the need for a ban of Pb shot for waterfowl hunting in Spain and the cleanup of spent shot at major wetlands. Keywords—Heavy metal contamination Lead shot Waterfowl Grit Wetland