The number of flamingos in Mumbai increased more than two times in January to over 1.21 lakh, according to the latest census conducted by the Bombay Natural History Society. The migration of a large number of birds into the city could have lifted the number, the society said.

The census counted a total of 121,900 flamingos in and around the coastal city during the month. Of this, 107,700 were lesser flamingos – nearly three times the number in December.

The number of greater flamingos declined 20% in January to 14,200, the study showed. Greater flamingos are taller and whiter. They have a mixed feeding pattern and mainly eat insects, small fish and algae. The lesser flamingos are comparatively smaller, with pinker plumage, and only feed on algae.

The study is part of the society’s 10-year ecological study on wading birds and was conducted at the eastern seafront of Mumbai, along the Sewri-Nhava sea scape, to understand the impact of developmental activities on them. The study began in May 2018, with the society conducting monthly surveys. The report was released on Saturday, on the occasion of World Wetlands Day.

“It is very encouraging to see a large number of flamingos arriving around Mumbai,” Bombay Natural History Society Assistant Director Rahul Khot said. “This underlines the importance of the critical habitats in and around the Mumbai region. It also highlights the necessity of such long-term comprehensive studies to understand migratory birds and chart future conservation plans.”

The society’s director, Deepak Apte, told Mumbai Mirror that the organisation had conducted simultaneous counts of all wetlands to ensure the same birds were not being counted again. “Simultaneous counting is a huge exercise and needs to be done only twice every season,” he said. “Now we are pretty sure this number [of January] is 95% accurate.”

The society earlier relied on isolated counting, in which the same bird could be counted again, which made data unreliable.

Apte said authorities need to be more responsible and sensitive while planning development in the region. “We also need to focus and work to clean the highly polluted eastern seafront, so that we provide toxicity-free habitat for flamingos and other migratory birds,” he said.

Apte said it would be too soon to comment on the pattern or the decline in number in the study’s first year, The Indian Express reported. “By next year, we will have a comparative data to draw a conclusion,” he added.

Next year, India is scheduled to host the Convention on Migratory Species.