Waterfowl swallow this lead shot while feeding. Studies by the U.S. Fish and Wildlife Service reveal that waterfowl swallow lead shot today at about the same rate as 30 years ago. This indicates that birds mainly swallow shot deposited during the most recent hunting season. Ducks that feed on plants and invertebrates in the water or on the surface are less likely to pick up lead shot that has settled into the bottom than ducks like pintails that may dig 4 or 5 inches into the bottom for tubers. Signs of Lead Poisoning Lead poisoning is not contagious.
Birds get it one by one, and it takes about three weeks for a bird to die of the disease.
One thing's sure. Every bird that dies from lead poisoning is one fewer bird to nest in the spring. And that means fewer waterfowl for hunters, birdwatchers and everyone else to enjoy. United States Department of the Interior, Fish and Wildlife Service.