Jimmy Feller, age 11, of Cottage Grove, Ore. , for his question:

Does each bird always sing the same song?

Some experts claim that the meadow lark has 28 different tunes. Others, who perhaps listen more closely, claim that he sings the same basic song with 28 or more different expressions. His basic tune sounds somewhat like Spring is here and he can use this lilting phrase with a variety of meanings which other meadowlarks understand. He can state a few things to birds of different species.

There are a few mimics in the bird world who can copy sounds and improvise a variety of calls of their own. These chatterboxes  include the cowbird and the starling, the parrot and the budgie. The star of this group is the  mocking bird who can mimic and also pour for ill a repertoire of his own lyrical numbers. But most birds seem to 'earn a note or a phrase from their parents and use it with different expressions as a complete language.

In the main., a bird aims to communicate only with his own species. But there is some evidence of a universal bird language. There is a cry of alarm to which many species react. A robin who spots a hawk sounds this S.O.S. and maybe 30 different birds and their families fly for cover.

The cry of a hungry young bird is also understood outside the family. When a young cowbird utters this distress call, it reaches the heart of a mother cardinal and she gives him the food intended ,or her own children. All the experts agree that birds use their voices to communicate with each other and the most thoughtful experts agr.je that they sometimes sing just for joy. A bird chorus with various singers answering each other certainly sounds like a glee club and an expression of joy may well be part of that universal bird language,

The male birds are the songsters and their language varies with the seasons. Most of them return from winter migration ahead of the females. Each male scouts for a homestead with a suitable building site and territory to provide his family with groceries. Then he sings loud and clear to stake his claim to his domain. Other birds of his species understand from his expression that they will have to fight him if they trespass on his territory.

This is important because a swallow, say, does not want other swallows eating the flies and moths intended for his family, though he does not mind sharing his domain with a family of seed eating morning doves. When the females return, the flurry of courtship begins. The male sings his same tune, but now it is a love song. Later, he will use the same call with still other expressions to instruct the young birds.

It is a challenge to identify different birds from their songs and if you are a good mimic you can sometimes join in the conversation. But birds do not use our musical scales and some can be copied only with recordings. When the records are played back, they attract answers from the birds and sometimes start up a full scale chorus in the tree tops.