Lead Poisoning of Waterfowl in Wisconsin

Abstract

The presence, prevalence, and significance of lead poisoning as a mortality factor of wild waterfowl in Wisconsin is reviewed. Since 1940, more than 1700 Canada geese (Branta canadensis) have succumbed to lead poisoning in Wisconsin. This surpasses the total Canada goose mortality due to lead poisoning reported in the literature for North America. Although the majority of lead poisoning outbreaks among geese occurred in the spring, total mortality was equally distributed between fall and spring outbreaks. Lead poisoning mortality among whistling swans (Olor columbianus) in Wisconsin annually takes a small number of the spring migrating population. Seven duck species were known victims of lead poisoning in Wisconsin, but this disease was not considered an important mortality factor of ducks in the state. The mallard (Anas platyrhynchos) was the major target of the disease. Some of the ecological factors found to be involved with lead poisoning of waterfowl in Wisconsin were climate, water levels, soil types, diet, and the timing of waterfowl migrations. The signs, pathological lesions, epizootiology, and significance of lead poisoning of waterfowl in Wisconsin were considered and discussed. 18 references.