WITH THE change in the season, the environment at the zoo has become melodious. Zoo visitors can now see birds literally on a song in their enclosures.
Zoo vet Dr UC Srivastava says the sounds produced by birds can be divided into two categories—call note and song notes.
Call note is the language in which birds carry on their everyday conversation.
They are concerned with coordination of the behaviour of other members of the same species in such activities as feeding, flocking, migration and response to predators. These notes usually tend to be short and simple. But it is, however, difficult to draw a hard and fast line between call notes and the song notes.
Many of the songs can be found a little more than a series of call notes.
Songs are part of a complex communication system that chiefly comes into operation during the breeding season. Usually, they are performed by a male to proclaim a territory and defend it against possible intruders. By singing a territory holder may be saying that he is unmated or may be broadcasting a message to likely rivals to tell them to keep away, Dr Srivastava said.
He further adds that each species has its own special song for attracting a mate, which is different from all other closely-related birds. Sometimes the song is most important in preventing species, which are very similar in appearance from pairing up and inter-breeding.
According to him it is very unusual for female birds to sing, particularly where there is a striking difference in plumage between the sexes. However the studies in ringed birds have shown that with some species it is not as rare as it was formerly supposed. Elaborate songs have been heard from the male and female of a number of species.
He says it’s true that no other bird in the world has inspired so much poetry and romance as the Nightingale. Beauty of its song is considered to be matcShless.
The fact that the Nightingale sings frequently during the hours of darkness, when most other birds are silent, is no doubt responsible for much of the hold it has on the imagination of the people. It sings just as often, but then its song mingles with those of other birds and loses much of its individuality.
Besides, Nightingale another fine songster is the Shama. It is a species, which inhabits the forests of South-East Asia.
It is a bird, which is constantly in demand as a cage-bird on account of its fine song. But, it is seldom trapped due to its obscurity. The best male Shama singer bird was superior to even Nightingale, Dr Srivastava said.