Members of Perur Lake Forum document bird population at an urban wetland for six years

A six-year study by the Perur Lake Forum team turns the spotlight on rapid decline of water birds in urban wetlands

Historians often describe Coimbatore as a beautiful woman adorned with a garland of navaratnams represented by the lakes of the River Noyyal. The river begins its 167-kilometre journey from Kooduthurai near Aalandurai and joins the Cauvery near Karur, filling up over 30 tanks along the way. One such navaratnam is the Perur- Sundakamuthur Lake or Perur Lake located in the southwestern edges of the city of Coimbatore. One such jewel is the Perur-Sundakamuthur Lake or Perur Lake located on southwestern edge of the city. It is at this wetland, a dedicated group of bird watchers of Perur Lake Forum — G Parameswaran (founder), R Sivashankar, R Vridhi, Sai Vivek, and Dilip Joshi — has been documenting monthly counts of birds for over six years. Their systematic monitoring of bird population was recently published by Indian Birds, a peer reviewed scientific journal.

“It’s an ongoing programme,” says Parameswaran adding that they analysed the status and population trends of as many as 125 species. The benchmark species among water birds that was abundant in the last six years, according to him, is the little cormorant.

Tracing the journey, Parameswaran explains that the team came together organically, an independent group that focussed on citizen science. “We started doing monthly counts drawing from my experiences in the US as the board member and member of the conservation society of Seattle Audubon Society. I was also a graduate of their Masters programme where they teach you to count birds, understand their habitat, movements, etc. We have applied the same ethics in our study,” he explains.

The team monitored Perur Lake once a month from May 2014 to April 2020, usually on second Saturdays where they walked around the lake for two hours and counted all birds that were seen or heard and recorded the information in a checklist. “The first two years were splendid because the monsoons were on time. In 2016, the monsoons failed, and there was sand mining activity, commercial fishing, and road widening that disrupted the wetland structure setting off disastrous consequences, like for example, a rapid decline in population of water birds.”

For young birders, Sivashankar and Vridhi, who come from an engineering background, the study helped them understand citizen science and data analysis of bird observations better. For architect Sai Vivek, who describes himself as an accidental bird watcher, the discipline helped him organise his regular work. “I often share my experience with students on how I graduated from a bird watcher to become a part of a focused study to get the discussion started on how to conserve city’s water bodies among other things. A synchronised bird count is a great way to create a foolproof database.”

Parameswaran is all praise for his team’s commitment to the project. “Rain or shine we are there with our binoculars, spotting scopes, and cameras. We analyse data, check for accuracy, understand the season etc. We need functioning ecosystems in good state to sustain for the future. Coimbatore has fabulous ecosystems with a thriving bio-diversity,” he says, adding that bird watchers in the city can adopt a wetland or a forest patch and start birding every month on a long-term basis. “That should be one of the desired outcomes of our study. From September to March, Coimbatore is a birding haven. Any direction you move, be it the wetlands or the forests, you will find birds. Common birds are the ones that anchor our ecosystem. Bird watching is exciting.”

The study also draws attention to the fact that the Perur Lake was actively considered for designation as a bird sanctuary because of the thriving population of migratory and resident birds.