COIMBATORE: A routine weekend birding expedition turned into an extraordinary ecological event on Sunday after more than 20 experienced birdwatchers from the Coimbatore Nature Society (CNS) encountered a massive, unprecedented gathering of Eurasian coots (Fulica atra) (Namakozhi in Tamil) at Achankulam Lake near Nilambur on the city's outskirts on Sunday morning.
The walk which commenced at 7 am, initially recorded expected winter visitors and a healthy population of Indian Spot-billed Ducks. However, as the team scanned the north-eastern and northern expanses of the vast waterbody, they discovered that nearly half of the entire wetland was blanketed by a dense, floating flock of coots.
Conservative field estimates place the gathering between 1,000 and 2,000 individuals-a staggering surge for a species that is typically spotted here only in single digits or small groups of a few dozen.
The bird gets its Tamil name, Namakozhi, because the distinct white frontal shield on its forehead resembles the traditional religious mark called a naamam, worn on the forehead.
Speaking to TNIE, Coimbatore Nature Society (CNS) president N Selvaraj said, "While the Eurasian Coot maintains a year-round residential breeding population in South India, a spike of this magnitude strongly indicates the early arrival of migratory flocks travelling from the Himalayas or the broader Palearctic region.
Historical data and online citizen-science databases show a clear pattern of increased coot frequencies in Tamil Nadu during September and October as freezing northern temperatures force these birds south. This early October influx at Achankulam highlights the wetland's vital role as a primary staging ground and refuge for long-distance winter migrants entering the region.
"In our nearly 15 years of continuous documentation and observation across Coimbatore's wetlands, we have rarely seen such an explosive, concentrated population of Eurasian Coots this early in the season," Selvaraj pointed out
The society emphasized that this unusual gathering warrants deeper ecological probing to understand changing migratory timelines and local habitat health. Beyond the coots, the diverse avian turnout this morning also featured notable sightings of Spot-billed Pelicans, Painted Storks, Asian Openbills, Garganeys, and Great Cormorants, alongside active migratory flocks of Blue-tailed Bee-eaters, Barn Swallows, and various sandpipers, underscoring the critical conservation value of Coimbatore's urban wetland systems.
Senior Principal Scientist at the Sálim Ali Centre for Ornithology and Natural History (SACON), P Pramod, told TNIE that he, along with a few others, had spotted similar gatherings of the birds at Achankulam about 15 years ago. He said it was good to see such large gatherings of the birds again. However, no study had been conducted to determine the reason behind the phenomenon.