In native North American legends, the phoenix is represented as the Thunderbird, a powerful spirit bird. Through its work, the earth is watered and vegetation grows, for lightning is believed to flash from its beak, and the beating of its wings is thought to result in the rolling of thunder. Often portrayed with an extra head on its abdomen, the majestic thunderbird is often accompanied by lesser bird spirits, frequently in the form of eagles or falcons. Thunderbird petroglyphs have been found across Canada and the United States. Evidence of similar figures has been found throughout Africa, Asia, and Europe.