Millions of blue tiger butterflies migrate towards Western Ghats to escape rains

Millions of blue tiger and dark blue tiger butterflies are flying from the Eastern Ghats towards the Western Ghats during an annual migration.

The Journey

The migration brings them across Tamil Nadu plains and the Mysore plateau as they escape the heavy North-East monsoon hitting Chennai and nearby districts. Butterfly watchers on the WhatsApp group Butterfly Migration India are counting the insects in cities like Salem, Erode, Tiruppur, Coimbatore, Madurai, and Kerala. CV Nishanth, a core member of The Nature and Butterfly Society, says some spots in Coimbatore recorded 100 to 120 butterflies per minute on October 18. The species making the trip include blue and dark blue tigers, common and double banded crows, and a few emigrants.

Life Cycle and Behavior

Dr Kalesh Sadasivan, a research associate with the Travancore Nature History Society and a Kerala State Board for Wildlife member, explains that the insects start this journey after pre-monsoon showers in the Eastern Ghats. Once they reach host plants in deep forests, they feed, mate, lay eggs, and then die. Later generations fly back to the Eastern Ghats around May when pre-monsoon rains arrive for the South-West monsoon. TNBS founder and president A Pavendan notes that the butterflies rest on trees by 3 pm and resume flying the next morning when skies are clear.

Context

Butterflies serve as a vital indicator of a healthy ecosystem and hold an important place in the food chain by feeding other species like spiders and birds. TNBS has documented 329 butterfly species in Tamil Nadu and provided baseline data for the Sathyamangalam Tiger Reserve.