The annual butterfly migration that typically commences from the Eastern Ghats to the Western Ghats during July and August was reportedly observed earlier in 2020. The unique movement of these butterflies, which breed in the southeastern regions of South India during the southwest monsoon season, is part of an important ecological event. Their progeny traditionally makes a return to the Western Ghats in October and November.
The Early Migration Phenomenon
For the first time in eight years, the butterfly migration kicked off sooner than expected. Major originating spots for the migrating species include the Eastern Ghats complex, consisting of the Yercaud hills (Shevaroy hills), Pachamalai, Kolli hills, and Kalvarayan. In contrast, the destination point generally tends to be in the western ghats hill ranges – the Nilgiris, Anamalai Tiger Reserve, Palani hills in Tamil Nadu, and Parambikulam Tiger Reserve in Kerala. Mainly four species of milkweed butterflies from the Danainae subfamily participate in the migration process – the Dark Blue Tiger, Blue Tiger, Common Crow, and the Double-branded, often known as tigers and crows.
Possible Causes for Early Migration
Multiple factors could have contributed to the early migration of the butterflies. Changes in the rainfall pattern, a noticeable increase in sunny days, and a significant surge in the butterfly population are among some possible reasons.
Butterfly Migration Research Project
In 2018, the Ferns Nature Conservation Society (FNCS) launched a citizen science project to study the migration ecology of milkweed butterflies in southern India, with support from the Forest and Wildlife Department.
About Butterflies
Belonging to the order Lepidoptera of phylum Arthropoda, butterflies are insects that share their order with moths. Adult butterflies are often recognized by large, brightly colored wings and conspicuous, fluttering flight.
Significance of Butterflies
The presence of butterflies in an area symbolizes rich biodiversity. As an indicator species, butterflies provide valuable information about the ecosystem’s overall health and the status of other species within the system. They reflect changes in environmental conditions and aspects of community composition. Additionally, they play a crucial role in pollination, thus aiding in the conservation of various plant species.
About Parambikulam Tiger Reserve
In the Southern Western Ghats of India, located in the Palakkad District of Kerala, lies the Parambikulam Tiger Reserve – a well-protected ecological segment in the Nelliampathy-Anamalai landscape. Declared as a Tiger Reserve during 2008-2009, it is home to the world’s first scientifically managed teak plantation that was later merged with the forest land. The reserve is famous for housing the world’s largest and oldest teak tree named ‘Kannimara’. This remarkable tree, thought to be 350 years old, has a height of 40m and girth of 6.4m. Various species of birds such as Grey-headed Fishing Eagle, the Peninsular Bay Owl, the Nilgiri Wood Pigeon, the Black-capped Kingfisher, the Great Black Woodpecker, and the Lesser Grey-headed Fish Eagle call this reserve their home.
