With wings that stretch over 2.7 meters (nine feet) from tip to tip, the California condor (Gymnogyps californianus) is North America's largest flying land bird. Condors soar across the skies of the U.S. states of California, Arizona, and Utah, and Baja California in Mexico. As scavengers, they feed only on dead animals. They are well built for the job: bald heads stay clean, sharp beaks and powerful jaws tear carcasses, and a natural resistance to infections protects them against disease. By eating dead animals, condors help keep diseases from spreading to people, livestock, and other wildlife.

California condors have made a great return to the wild since the 1980s. Condors were almost wiped out by habitat loss, poisoning by traps set for coyotes, and hunting by humans. Today, condors are still in danger of getting sick from poisonous lead bullets in the bodies of animals they eat, but they are coming back. In 1987, there were fewer than 30 condors in the world. They were all taken to protected breeding areas in southern California. Now, there are more than 560 condors in the world, and over half fly free over North America. Condors are nature’s clean-up crew, and their sensitivity to toxins from human activity means they are an important measure of a healthy ecosystem.