Because eBird checklists were the source of data, Viswanathan and team estimated the proportion of checklists where a species appeared, in order to quantify trends like increase and decrease of species. The researchers looked at these trends in the long-term (over the past 25 years) and short-term (over five years, from 2014 to 2018).

According to their analyses, species adapted to living alongside humans are doing well. The house crow sees a long-term upward trend of 47 per cent and the rock pigeon shows a 144 per cent increase. Common myna is up by 11 per cent and rose-ringed parakeet by 19 per cent. The common tailorbird sees a 13 per cent rise while ashy and plain prinias are up by 105 and 121 per cent, respectively. With a hundred per cent increase, our national bird, the Indian peafowl shows a clear upward trend — a result of both an expansion of its range and increase in population.

Our friendly house sparrow had seemed to be declining everywhere in the country, with people reporting not seeing this familiar bird frequently anymore. But the report shows that while it has indeed declined in big cities like Bengaluru, Chennai, Delhi, Hyderabad, Kolkata, and Mumbai, the species has remained stable across the country on the whole. This was a surprising and pleasant result, Viswanathan says.