Birds have two basic types of sounds: song and calls. Songs are usually more complex than calls and utilized primarily by adult males during the breeding season to establish territories or attract mates. Calls are normally simple notes, single or repeated, vocalized by males and females in all seasons to express alarmor maintain contact with mates, offspring, or other birds of the same species. All songs and most calls are distinctive, and with concentrated study and practice, bird- watchers can learn to identify many birds by their sounds and to call them well.