The annual bird survey conducted by the Tamil Nadu Forest Department in a number of wetlands, showed a significant drop in the number of bird species at the Vedanthangal Bird Sanctuary and the Karikili Bird Sanctuary in Chengalpattu districts, and the Pulicat Bird Sanctuary in Tiruvallur district.
According to official data, 49 species of birds were seen at lakes around Vedanthangal on January 29 this year. This is a steep drop from the 83 species spotted on the same day last year. The total number of birds spotted sawan even more drastic decline from 44,972 in 2022 to 9,703 this year.
At the Karikili Bird Sanctuary, 30 species and 463 birds were counted. The Pulicat Bird Sactuary saw marginal drop in the number of species from 97 last year to 92 this year, while the bird count also went down from 5,688 in 2022 to 4,916 in 2023.
Forest Department officials and environmentalists attributed the drop in bird arrivals in Vedanthangal to the empty Maduranthakam lake, which is the feeding ground for birds and also one of the largest waterbodies in Chengalpattu district. The Water Resources Department had initiated desilting of the lake a few months ago.
“Good rainfall during the Northeast monsoon alone will not ensure birds in Vedanthangal. The feeding area is also important,” said an environmentalist. He also said the sanctuary got surplus water from Valayaputhur lake only after Cyclone Mandous, which occurred in December. By that time, the birds would have already started to move to other places.
Another environmentalist pointed out that Valayaputhur lake will not make up for Maduranthakam lake, in terms of serving as a feeding ground. “Birds can perceive a sudden change as a sign of a threat and move elsewhere,” he said. There have also been reports of village residents blocking the flow of water from Valayaputhur lake to Vedanthangal, which could be a factor for the low bird number.
Some bird watchers now fear that the drop in bird arrivals will persist throughout and beyond the timeline of the desilting of Maduranthakam.
The bird census in the Chennai division was done at 23 locations including at the Pallikaranai marshland, Adyar estuary, Nanmangalam, Chitlapakkam, and Velachery. The total number of birds spotted in Chennai division was 28,602.
