COIMBATORE: The Nature and Butterfly Society (TNBS) has observed that the summer and pre-monsoon butterfly migration is active in the state’s western districts.
The observations made by a team headed by A Pavendhan pointed out that the migration last year was below par with the regular migration count. The members of the society were directly involved in the observation beginning on April 14.
Pavendhan said, “Butterfly migration from the Western to Eastern Ghats, an annual event, especially over the western districts of Tamil Nadu was active during the current year especially during April to escape from the harsh climatic conditions including heat and rain. Butterflies from the sub-family Danainae, called tigers and crows (especially Blue Tiger, Dark Blue Tiger, Double-branded Crow, and Common Crow) migrate from the western ghats towards the nearest hill ranges before the start of southwest monsoon (from mid of April to May). During the current year, the active migration months of April and May saw reasonable migration of these Tigers and Crows.”
The observers claimed that the migration of crows and blues at a rate of 25-30 per minute was observed flying from the southwest to the northeast.
The observations were made at Pollachi and Coimbatore cities and the direction of movement pointed towards Tiruppur, Erode, and Sathyamangalam. The movement was active between 8 am and 1 pm. It was observed till April 21.
From Nilgiris, observation was made at Kothagiri, where again the movement was towards Sathyamangalam.
Another burst was observed on May 11 over Tiruppur headed by members S Gopalakrishnan and H Ramanasaran. However, some regular routes over which the migration is usually observed did not see any movement, a report stated.
The society observed that the current year movement was considered healthier compared to the last few years.
The report also stated, “The pre-summer migration count is always lower in scale compared to pre-winter migration of crows and tigers. We also see a good correlation between healthy butterfly movements and good rainy season that follow immediately.”
The Nature and Butterfly Society has been observing the migration
of butterflies since 2013 and the observations are shared with the large portal- butterfly migration of India, where information from all states is collated for deeper understanding.