THOOTHUKUDI: With man's advancements ousting countless animals and birds from their habitats with each passing year, the scenes from Perungulam tank in Thoothukudi are always a welcome anomaly. Having water round the year, the tank is a key feeding site for migratory birds, and it supports a huge population of birds and animals. Knowing fully well how 'development' tickles the human fancy, wildlife enthusiasts and local residents have urged the government to take steps to get the Biodiversity Heritage Site (BHS) tag for Perungulam tank.
This tank is the last in the chain of 16 tanks in Thamirabarani East channel. It is bisected by Ucham Parambu mound, which shelters various native trees and thorny bushes. The tank, spread over 900 acres of land, is bordered by Perungulam town panchayat on the east and Sivagalai on the west. Despite being fed by the historic Thamirabarani river, Perungulam tank receives rains during both southwest and northeast monsoons. Bird watchers and those who contribute to the bird census preparation say, over 5,000 birds visit the tank every year.
"Unlike other tanks, Perungulam welcomes winged visitors throughout the year. Most birds arrive when the tank water is shallow during summer and pre-monsoon seasons for feeding and roosting. Other tanks would usually dry up during these seasons," says Thomas Mathibalan, President of Pearlcity Nature Trust and a birder who counts birds during every wetland bird census.
Further, the tank has Sivaite Thiruvazhutheeswarar temple on its northeast corner and Vaishnavite Maya Koothar Perumal temple adjacent to it, both over 1000 years old. However, the intersection of high tension towers shouldering power lines cutting across the tank have the residents and birders worried.
Manickam, a history teacher from Sivagalai told TNIE the towers were installed on the Ucham Parambu, which is on the edge of the current archaeological site, during the Covid-19-induced lockdown despite severe opposition. "The authorities should provide adequate resting places for migratory birds to ensure that they don't hit the power lines and other manmade structures," he added.
Pointing out that migratory birds have been flying to Perungulam tank from various parts of the world for the past many centuries, Sivagalai Keela Kaspa Farmers Association President Arunachalam urged the governments to protect the site.
Senior Research Associate at Ashoka Trust for Research in Ecology and the Environment M Mathivanan said among the wetland bird species regularly observed in the tank, at least 56 per cent reside and breed within the district. "Previous bird census data strongly suggests that Perungulam tank has a high degree of avifaunal diversity. The tank also has rich aquatic flora that attracts wildfowls, marsh birds and odonates. A Biodiversity Heritage Site tag must be sought for Perungulam tank since it qualifies in three of the nine criteria for identifying 'Wetlands of International Importance', as per the Ramsar Convention," he said.
Number speaks
54 wetland bird species belonging to 42 genera and 19 families are found in Perungulam tank, according to an analysis of Tamirabarani Waterbirds Count (TWC) conducted by Ashoka Trust for Research in Ecology and the Environment between 2011 and 2019.
Near threatened
Six bird species categorised as 'near threatened' in the IUCN Red List Category -- spot-billed pelican, darter, painted stork, oriental white ibis, black-tailed godwit and river tern -- regularly visit the tank and they account for about 11 per cent of the bird population here. The biodiversity of the tank also supports protected species such as black ibis, which is a Biome-Restricted Species (BRS), and Eurasian spoonbill that finds mention in Schedule 1 of the Wildlife (Protection) Act, 1972.