Not all birds can sing. The passerines, or songbirds, comprise about half of the world’s 10,000 avian species. They are characterized by their special muscular voice box, the syrinx, which consists of one set of vocal cords located at the top of each lung. Each set of vocal cords is controlled separately, which allows birds to sing two different notes at the same time. Surprisingly, birds can also sing with their beaks closed or while they are eating.... Keep reading
