Lead poisoning affects waterfowl and raptors across North America.  Lead poisoning is caused by the ingestion of lead pellets from spent ammunition, and less commonly, lead fishing sinkers, mine waste, and other lead objects that are swallowed.  Lead poisoning occurs when hazardous levels of the material are absorbed in the body tissue.  Waterfowl may ingest lead shot while feeding in areas used for target shooting or feeding in areas where lead shot is allowed for harvesting other species.  Raptors may swallow lead shot embedded in carcasses.  Signs of lead poisoning include weak flight or no flight, an unsteady gait, wing droop, or an unwillingness to escape when approached.  People who eat lead-poisoned birds are not at risk for the disease as a large number of birds would have to be consumed within a short period to cause toxicity.