New Delhi, May 6 -- The Delhi government is set to release the Capital's first "Bird Atlas", a detailed book on Delhi's bird diversity in terms of species and their distribution, as part of its annual Van Mahotsav celebrations next month. Three surveys have already been held since last year-two in winter and one in summer survey-and a fourth survey is underway since May 1, with an end date of June 30, officials said. "The atlas will be formally launched next month, as part of the annual Van Mahotsav celebrations, where massive plantation drives will be held in Delhi. Ministers from the Delhi government and the central government will take part in it," a government official, who did not wish to be named, said. The official said the atlas wil...