In a unique effort to identify just such snatches of birdsong, the Bombay Natural History Society (BNHS) recently released two audio cassettes entitled Indian Bird Calls which contains bird calls of 169 species of Indian birds at a function in Mumbai. Interestingly, the cassettes are the result of recordings of three recordists, Brother Antonio Navarro, B. Bertram and Erach Bharucha over different periods of time at various sites across the country.

``Some birds are easier to listen to than to see. The aim behind the project is to create a larger degree of awareness about birds,'' says Bharucha who took upon himself the extensive task of compiling bird call recordings. The Pune-based ornithologist and wildlife enthusiast had his work cut out for him. Says Bharucha, ``In the 1950s I remember coming across Brother Antonio Navarro as he was recording bird songs here in Pune. I had heard that the recordings amounting to about 30 tapes of birdsong mainly from the Western Ghats were lying unused with the St. Xavier's society. Two decades later, B. Bertram, an English ornithologist who was conducting research on hill mynahs in the Himalayas, also identified many sub-species by their calls. He presented his recordings of Himalayan bird calls contained in some 12 tapes with verbal identification of the birds to the BNHS.''

Bharucha was himself interested in bird calls and had collected bird calls from across the country, mainly the Western Ghats, the Dangs in Gujarat, Coimbatore, Kerala and the Himalayan foothills all of which amounted to about 50 cassettes. ``I would travel to their habitat with a pair of binoculars, a small recorder and a highly sensitive microphone which could easily capture sounds 40 feet away,'' says Bharucha.

With the idea of compiling the various bird calls into one compact collection, Bharucha, under the aegis of the BNHS, started work three years ago. ``I had to select appropriate calls, index their placement on the cassette. This meant I had to listen to all the magpies through the collection and select the best magpie. Besides bird calls serve different purposes and differ accordingly, like breeding calls usually made by the male, alarm calls where other species of birds also join in, a contact call which consist of a call and counter-call and even those that announce territorial marking,'' says Bharucha.

The meticulous preparation included clearing the tapes of the dust gathered over the years, and identifying calls using the verbalisation noted in Salim Ali and S Dillon Ripley's Handbook of the birds of India and Pakistan. This data was fed into a computer and unwanted calls and unclear recordings had to be edited on a CD with the help of Sharad Navle and his team of computer professionals. The calls are preceded by a verbal identification. ``This was a painstaking task which took 10 days of dedicated effort. The tapes include recordings, 40 per cent of which are Bertram's and mine and the other 20 per cent, Navarro's,'' says Bharucha. He was also helped by students of the Bharati Vidyapeeth Institute of Environment education and research where he is director as well as by Bharat Bhushan and Kiran Purandare who helped him to identify obscure calls.

An interesting discovery that Bharucha made during the compilation was the differences in background sounds in the recordings of bird calls in Lonavala made by Brother Navarro three decades ago and his own recent ones. ``The older recordings have a much larger number of birds in the background, and include sounds of barking deer, the pied hornbill, malabar giant squirrels, sambar which have vanished in the intervening period as is apparent in my tapes.''

When the initial idea of a CD-ROM was not thought financially viable, the BNHS settled on audio tapes which was edited by J. C. Daniel. A small handbook which comes along with the set of cassettes gives information about the bird's habitat and also identifies the calls of other birds in the background.

For Bharucha it has been a rewarding mission. ``Bird calls too have their aesthetic appeal, like the call of the Scimitar Babbler found in deciduous forests which consists of a duet between the male and female of the species. The Malabar Whistling Thrush lives up to its other name - the Whistling Schoolboy.''

Through the set of cassettes, which should be released in Pune in a fortnight's time, the BNHS hopes to generate awareness about birds. ``We hope that awareness will translate into concrete action towards wildlife conservation,'' says Bharucha. A call that needs to be heeded.