The 129 ha Koodankulam lake gives its name to the village, as kulam means a lake in Tamil. Koondakulam receives water from the Manimuthar canal and lies to the western side of the village. This lake and neighbouring waterbodies like Kandankulam, Ilamalkulam, Sungulam and Vijayanarayanam lake are brimming with fish and other small aquatic life after the monsoons and serve as feeding ground for waterfowl.

The avian visitors to the lake include painted storks, spot-billed pelicans, egrets, Eurasian spoonbills, blackcrowned night herons and flamingoes. These birds arrive in November-December every year and their nesting homes are in almost every neem and tamarind tree in the village. At times they are even found on the low-slung prosopis trees. All the species of birds that come here can be easily spotted in the village except for the grey herons and the spoonbills which home on the trees on the farther side of Koodankulam tank. Hundreds of grey pelicans, spoonbills and darter birds nest on Acacia nilotica trees on the Koodankulam lakeside.

The population of the village is around 9000, with most of the people being agriculturists. The villagers are mostly vegetarian.

The village of Koodankulam is a site where painted storks, known to the villagers as sangulavlai narai, come to breed and have been protected by the villagers for more than 200 years. Pate, a former Collector of Tirunelveli, has recorded in the District Gazetteer in 1914 that pelicans fed regularly in the nearby Vijayanaranyanam Lake.

The acacia trees, which now provide shelter to the birds, were planted under the Social Forestry Scheme by the forest department. In 1993, the forest department tried to auction off these trees for fuelwood. This is when the villagers got together and through their panchayat persuaded the forest department to spare the trees. In 1994, this place was declared a sanctuary and a village committee was formed to look after the birds.

The villagers consider the waterbirds as harbingers of rain, prosperity and a good harvest. The bird droppings, called guano, is rich in nitrates and phosphates and provide a good source of manure in the fields. Apart from this, large quantities of the guano also settle in the tanks, the waters of which are used to irrigate the fields. Thus, the bird droppings play an important role in improving the livelihood of the agriculturist villagers.

In addition to protecting the birds, the villagers also found it important to get together and persuade the forest department not to auction off the acacia trees which provide shelter to these birds. 

The significance of fostering the birds is well-embedded in young and the old villagers alike. The children in the village are trained to monitor bird casualties and report to the elders.

The children in the village monitor bird casualties and report them to the elders. The cause of death of the birds is then ascertained, and any person found guilty is punished. Once a man was found guilty of killing a fledgling. As a punishment his head was shaved and he was paraded on a donkey with the bird tied around his neck.

There are some instances where fledglings fall out of their nests. The villagers make efforts to put them back in their nests or nurse them at home till they are old enough to fend for themselves. Koodankulam has a small ‘nursery’ where these birds are reared and fed fresh stock of fish. One villager is appointed in charge of the nursery.

Waterfowl gather in these lakes in large numbers during the breeding season and nest in colonies in secure spots where food is plentiful. In the countryside around Koodankulam, a large number of other species of birds are also seen, such as the brahminy kite and Montague’s harrier, black ibis, cattle egret, and Indian roller. All the birds that nest in Koodankulam are local ones and not migratory. Migratory birds also come to these lakes, but they come only in the winters and only to feed. Such birds include the black-winged stilt, sandpipers, godwits, Northern pintails, mallards, blue-winged teals, comb ducks and the bar-headed goose. The bar-headed geese breed in Ladakh and come south in the winters. This is the southernmost point where they can be seen. The presence of such high numbers of fish and bird population indicates low or no pesticide contamination of the lakes.

Till recently, Koodankulam was a remote and unknown village because of which few visitors frequented the village. The scenario started to change when an enterprising travel agent included this village in his itinerary. During the season, hundreds of tourists have now started coming here more as a picnic spot rather than to observe birds. Since these tourists are unaware of the importance of this site as a bird habitat, they end up causing much disturbance to the birds. The villagers need to make serious and conscious efforts against the dangers of such tourism to ensure that birds remain safe and undisturbed in this village.

It is believed that years ago painted storks used to nest in the tamarind trees in Moondradaipu village on the main Tirunelveli-Nagarcoil highway. With the increase in vehicular traffic and harassment, the birds have abandoned that spot and moved here. Efforts need to be made to ensure that the same situation is not repeated here.