Butterflies are back in Chennai, in huge congregations of yellow, blue, brown and red. They have been spotted following the coastline on beaches, flying West from terraces, resting en masse on the ground in parks. They usually are, every year, after a spell of showers.
But this year, something is different. The numbers, for one, are massive.
“On July 8 alone, we saw 8,000 Lime Blue butterflies at Guindy National Park, and around 2,000 each of the Common Lime and Common Emigrant species on July 13,” says enthusiast Vikas Madhav.
Nature educationist and writer R Bhanumathi says, “I saw a single congregation of around a hundred Lime Blues recently, mud puddling.”
Bhanumathi has been documenting butterflies for 30 years, and adds that she can’t recall having seen so many at one time after the mid-1990s. She says Common Limes, Emigrants and Lime Blues are the main species spotted in surprising numbers across the city.
It isn’t just butterflies. According to observer and enthusiast S Venkatraaman, the populations of wasps, bees and ants have seen a spurt as well. “Butterflies are more noticeable,” he says.
The sightings have sent flutters of excitement at various sites across the city: from the campuses of IIT Madras and CSIR (Council of Scientific & Industrial Research), to the national park at Guindy and the Tholkappia Poonga. Surprisingly, says Venkatraaman, residents have also noted an unusual number of butterflies in unlikely areas like Velachery, though not on a large scale.
The species seen most often — besides the three already mentioned — are Painted Lady, Crimson Rose and Common Jezebel. While the presence of some is unsurprising, the others are a whole different story.
“The Common Lime, Painted Lady, Common Emigrant, Common Jezebel and Crimson Rose have been seen by people following the coastline. These species are migrating South,” Madhav says, adding that certain species are migrating West as well. This migration is usual for this time of year, as is the return migration around September, he says. The massive numbers within Chennai, however, have left documenters perplexed.
Theories abound in plenty, though most enthusiasts want to take their time and consult scientists before they come to any conclusion. Pauline Deborah, Associate Professor at Women’s Christian College’s Department of Plant Biology and Biotechnology, reiterates that the spurt has been in particular species, and says recent climate variations might be a reason.
“Erratic rains cause erratic flowering patterns,” says Deborah, “which causes changes in the feeding patterns of butterflies and caterpillars. Some species are dependent on particular plants, and seasonal variations have had an impact. Plants which would earlier bloom in, say, October or November, now do so randomly.”
Bhanumathi explains, “Caterpillars and larvae need young shoots and leaves to feed on.” The environmental upsets post Cyclone Vardah meant that, somehow, fresh shoots haven’t sprouted for months. “Usually, this region sees sporadic rains every now and then. This year, there haven’t been any significant showers since January, when the cyclone struck,” says Madhav, “Flowers such as gulmohar have begun producing nectar, and butterflies that are dependent on them have revived.”
Deborah says indigenous trees such as premna and ironwood are also important for butterflies, but people in the city have begun introducing more of exotic plants for decorative reasons, “causing erratic flowering patterns and change in feeding availability”.
A lot of the congregations spotted, were seen mud-puddling en masse. “Mud-puddling is done by male butterflies, after fresh rains,” says Bhanumathi, “There are certain minerals and nutrients found on the wet ground that cannot be taken from nectar. These are the nutrients needed for reproduction. The butterflies can now focus on multiplying, as the rains have ensured plenty of nectar, young shoots and new leaves for the young to eat and survive.”
When butterflies — in any stage, even caterpillars and larvae — have nothing to survive on, they go dormant and can stay so for weeks. But now that the rains have revived, so has the circle of life, creating colourful flutters across the city.
