The twittering of birds usually produces a pleasant sensation, especially in the spring in countryside. Some birds produce very sweet sounds while others produce harsh and unpleasant sounds. Do you know why birds sing?
The songs and calls are important methods of communication among birds. They sing to attract mates in the mating season, to warn other birds of any incoming danger from predators, and to establish their home territories or nesting area. The bird calls are usually distinctive and vary from species to species. This distinction helps the birds to identify the calls meant for them.
Among all the species of the singing birds, the male bird is usually the singer. It sings to attract the female bird. The songs of nightingale produce the best musical effects and other birds do not match it in comparison. The mocking bird has its own harsh call but can imitate the songs of other birds. Crow has a very crude voice.
Apart from singing, birds make other types of calls — call for sending alarm signals, for food or calling their parents, call in an aggressive or hostile mood etc. A few birds, such as pelicans and cormorants, are voiceless.
The singing birds belong to the suborder oscines. Their vocal cords are located in a special box, the syrinx, at the base of the windpipe where it divides into two bronchi. The syrinx has a bony structure and forms a sound-box within which membranes vibrate when the bird exhales. This produces varying notes in the bird’s voice. The structure of syrinx varies from species to species and till now seven different types have been recognized.
The songs of the birds have a pitch of about 4300 Hertz, which is above the highest note of a piano. Intensity of the calls of any single bird varies from the deep-pitched hoot of owls to the very high notes of small birds which are scarcely audible to the human ear.