New Delhi: Three bird species -- Common Babbler, Brown Rock Chat and White Browed Wagtail -- have declined rapidly in Delhi over the three decades, a new report says.
Common Babbler numbers have dipped by 81 per cent, Brown Rock Chat by 65 per cent and White Browed Wagtail by 85 per cent during this period, according to the "State of India's Birds" report released on Friday. "The number of insectivorous birds is declining in Delhi due to the overall decline in the insect population. Though there is no data, anecdotal evidence confirms this," conservationist Sohail Madan, who contributed to the report, said.
Of the 338 bird species studied in India for changes in numbers over the last 30 years, 60 per cent have experienced a decline, the report compiled using data from about 30,000 birdwatchers across the country, said. Also, 40 per cent (142) of the 359 species evaluated for change over the last seven years have declined, according to the report.
The assessments rely on three indices: two are related to the change in abundance -- long-term trend (change over 30 years) and current annual trend (change over the past seven years) -- and the third is a measure of distribution range size within India. The researchers involved in the study said they do not have specific reasons for each species' decline, and stressed the need for rigorous research to find out why this is happening.
"Also, it is not clear if there is a link between the increase in certain species and the decline in the others," one of the conservationists said. (PTI)
