Dark Blue Tiger. Photo: G. Moorthy | Photo Credit: G_Moorthy
The Ferns Naturalists’ Society (FNS), Wayanad, Travancore Natural History Society (TNHS), and the Malabar Natural History Society (MNHS) have joined hands to launch a citizen science project to map the migratory path of butterflies in south India — the first such initiative in the country.
Usually butterfly migration starts during October-November with the onset of the northeast monsoon, from the plains to the ghats, and during April-May, just before the advent of the southwest monsoon, from the ghats to the plains.
A recent study revealed that four species of milkweed butterflies are mainly involved in the migration — the Dakhan Dark Blue Tiger, Oriental Blue Tiger, Double-branded Black Crow and Indian Common Crow. The migration takes place across the plains of south India to the southern part of the Western Ghats.
Migrant butterflies initially remain in reproductive diapause for a few weeks after reaching the Western Ghats. They breed in the mountain ranges and their progeny migrate to the eastern plains and Eastern Ghats area. The butterflies leave the Western Ghats just before the onset of the southwest monsoon and return after the monsoon. Thus, they avoid the cold weather and heavy rain in the southern Western Ghats. These butterflies breed during the southwest monsoon season on the eastern areas of south India and their progeny migrate back to the Western Ghats in October-November.
“Information on butterfly migration in India is still patchy,” Jaffer Palot of the MNHS said.
“What is needed is a careful documentation of migration over a prolonged period from a given area. For this, a wide network and coordination among butterfly watchers from different localities are needed,” Dr. Palot said.
“Butterfly migration is one of the least studied natural phenomenon in the country. We constituted two butterfly migration monitoring groups on WhatsApp last year to study the phenomena,” said Kalesh Sadasivan, research associate, TNHS. “Now we have 276 volunteers in the group from all over southern India who log in reports,” he said.
Each record is followed up at the next place and thus the whole migration track is delineated, he added
Dr. Sadasivan says the group, Butterflies of Kerala and Butterfly Migration ,would be in a position to give exact information in this regard from next year.
“We need more people to volunteer and report this, he added. If the Forest Department’s in Kerala, Karnataka and Tamil Nadu would come forward to support the citizen science project, the MoEF can make it as a nationwide programme,” P.A. Vinayan of the Ferns said. Those interested in joining the group may contact 94470 44498, he said.
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