Relative Toxicity of Lead and Selected Substitute Shot Types to Game Farm Mallards

Abstract
The acute toxicity of lead, 3 types of plastic-coated lead, 2 lead-magnesium alloys, iron, copper, zinc-coated iron, and molybdenum-coated iron shot were tested in year-old male game farm mallards. Mallards (Anas platyrhynchos) were fed 8 number 6 shot of each type and observed for a period of 60 days. Ducks used totaled 230 and most shot types were tested in 3 replicates of 8 ducks each. Mortality and losses of body weight were the criteria used for judging toxicity. Three types of plastic-coated lead shot were as toxic (93 percent) as the commercial lead shot (96 percent). The average mortality in mallards fed lead-magnesium alloy shot was less (58 percent) than that occurring in birds fed commercial lead shot. Mortality among mallards fed iron, copper, zinc-coated iron or molybdenum-coated iron shot was significantly less than in birds fed lead shot, and was not significantly greater than the controls.