Cranes are tall birds with long legs. Cranes are large birds, the world's tallest flying birds. They range in size from the demoiselle crane, which is 90 cm (35 in) in length, to the sarus crane, which may be up to 176 cm (69 in). The heaviest is the red-crowned crane, which can weigh 12 kg (26 lb) before migrating. They are usually brown, white, or gray in color. There are over 15 kinds of species of cranes. They look rather like herons. The whooping crane ("Grus americana") is the tallest American bird. Adults stand 5 feet tall and have a wingspan of up to 7 feet.