Comparing erosion and organ accumulation rates of lead and alternative lead-free ammunition fed to captive domestic ducks

Lead poisoning of birds of prey from ingestion of ammunition lead has been well documented. Alternative, lead-free ammunition is widely available, but the toxicokinetics of other metals in birds are poorly understood. We tested the erosion of lead, copper, zinc, iron and brass by feeding domestic Pekin ducks (Anas platyrhynchos forma domestica) defined numbers of small metal pellets. The accumulation of these metals was analysed in the breast muscle, brain, pancreas, liver and kidney. Four weeks after application, the ducks were euthanized and necropsied, internal organs tested for metal accumulation and gizzard pellets collected and weighed to record loss by erosion. Degree of erosion was highest in zinc pellets (81% mass loss), followed by iron (46%) and lead (45%) and was only marginal in copper and brass. Only lead showed highly elevated levels of accumulation in organs compared to controls.