Last Sunday, the Anaimalai Hills Range in the Western Ghats saw a streak of colours. Millions of butterflies — Common Emigrants, Common Albatross and Plain Puffins –— fluttered across the valley as they moved to an unknown destination. “There were yellows, whites and blues as a long chain of common emigrants moved swiftly towards Athirapally in Kerala,” says H. Theivaprakash of the Tamil Nadu Butterfly Society (TNBS).
Another member C.V. Nishanth calls it a euphoric moment when he spotted a large congregation of butterflies at Keeriparai village, near Kanyakumari. Two others, Amrith Balan and Shiva Kumar, alerted him about the movement. “Keeriparai is on a hillock and rubber estates abound. A stream snakes through the village. That is where I saw them. The sight took my breath away,” he exclaims. He also spotted butterflies moving from Singanallur and Puliakulam in the city towards Periyanaickenplayam. “They take the same path and move all through the day. The highways pose a danger and there are several road kills during these months,” says Nishanth.
Naturalists have observed the movement of butterflies all across the Western Ghats. “We have received data from Top Slip, Valparai, Anaimalai tiger Reserve, and also in Theni district. Recently, from Mudumalai in The Nilgiris too,” says A. Pavendhan, founder of TNBS. Along with the migration of common emigrants, there is also the milk weed migration where species like blue tigers and common crow migrate from plains to the hills during April to May and then from the hills to the plains in September.
Butterfly migration has continued to baffle naturalists. “There have been observations in the 1920s and 1940s during the British reign. They have studied the butterfly migration in Palani Hills in the 1940s. Butterflies move in multi-directions and no one knows where they are going. Several theories have been floated,but what we need is a long-term study,” explains Paavendhan. Nishanth adds, “Migration of the monarch butterflies in the U.S. was studied extensively. They used radio sensors to track their path. We have no such studies done here.”
The sudden surge of butterflies is often attributed to the availability or non-availability of host plants (every butterfly species has a specific host plant). Sometimes, it is the harsh weather. In Tamil Nadu, the summer rains are considered a trigger point for the significant movement of butterflies. “We saw the migration at Valparai, Amrita University campus at Ettimadai, and at Ponnuthu near Thudiyalur right from the second week of May, immediately after the rains,” says Theivaprakash. He was lucky enough to also spot a rare butterfly, the Five-bar Swordtail. “We were surprised to see the yellow-coloured butterfly with black and white marking in the midst of the congregation of common emigrants.”
The butterflies disperse locally within five to 10 kms and sometimes over a long distance of as much as 100 kms. “Last year in October, the butterflies moved towards the plains for two or three days from Pachamalai in Tiruchi. They ended up at the foothills of the Western Ghats. We sighted a few of them here. It’s still a mystery on where they are going. At some point they move towards the plains.”
One shouldn’t miss the beautiful sight, says Pavendhan. “They keep moving in a straight line – like disciplined school students, and occasionally stop for mud puddling. It will be a steady flow. Butterflies are an indication of good ecosystem and environment. And the migration is a sign of hope that our environment it still intact.”
In your neighbourhood
Look out for butterflies in your neighbourhood. You can sight them anywhere as they keep moving across the city
If you spot a butterfly in your neighbourhood, email details to tamilnadubutterflies@gmail.com or visit the Tamil Nadu Butterflies page on Facebook and post the info
You can spot butterfly migration till the end of May. And, again from September to October end
