secondary poisoning impacts, which eventually lead to death. Among condors around the Grand Canyon, lead poisoning because of eating lead shot is the most frequently diagnosed cause of death. Restrictions on the use of lead Depending on hunting laws, alternatives to lead shot are mandated for use by hunters in certain locations or when hunting migratory waterfowl and migratory birds or when hunting within U.S. federal waterfowl production areas, U.S. national wildlife refuges, or some state wildlife management areas. Lead shot is also banned within an eight-county area in California designated as the condor's range. As of 2011, thirty-five states prohibited lead shot use in such specially-specified areas when hunting. While hunting non-migratory or upland birds, as well as animals, in the United States, lead shot is generally approved, except within the specially-designated non-toxic shot pellet zones. In an effort to protect the condor, the use of projectiles containing lead has been banned for hunting deer, wild pig, elk, pronghorn antelope, coyotes, ground squirrels, and other non-game wildlife in areas of California designated as its range. The bald eagle has similarly been shown to be affected by lead originating from dead or wounded waterfowl—the requirement to protect this species was one of the biggest factors behind laws being introduced in 1991 by the United States Fish and Wildlife Service to ban lead shot in migratory waterfowl hunting. Hunting restrictions have also banned the use of lead shot while hunting migratory waterfowl in at least 29 countries across by international agreement, for example the Agreement on the Conservation of African-Eurasian Migratory Waterbirds. Depending on hunting laws, alternatives to lead shot are mandated for use by hunters in some locations when hunting migratory birds, notably waterfowl. In the US, the restrictions are limited to migratory waterfowl, while Canadian restrictions are wider and apply (with some exceptions) to all migratory birds. The hunting of upland migratory birds such as mourning doves was specifically excluded from the 1991 US restrictions as scientific evidence did not support their contribution to the poisoning of bald eagles. In 1985, Denmark banned the use of lead in wetlands covered by the Ramsar Convention, later expanding this restriction to the whole country. The use of lead has been banned for all hunting activities in the Netherlands as of 1992. The Missouri Department of Conservation introduced regulations in 2007 in some hunting areas requiring the use of non-toxic shot to