Context- Recently a three-day survey in western ghat finds 191 species of the insect, 12 of which are endemic to the biodiversity-rich region.

Key findings

• The survey was conducted in all the four forest ranges under the sanctuary, including Muthanga, Tholpetty, Kurichyad and Sulthan Bathery, simultaneously.
• The survey was mainly aimed at assessing the butterfly diversity in the forest areas of the region, which is vulnerable to climatic changes. It was also wanted to assess the availability of nectar plant and larval host plant, essential for the survival of butterflies. As many as 18 camps were set up.
• The Western Ghats is still home to a kaleidoscope of butterflies. A survey that ended in the Wayanad Wildlife Sanctuary (WWS) on Monday could sight 191 species, 12 of which are endemic to the biodiversity-rich region.
• The first-time sighting of Silver forget me not, Common three ring, and Brown onyx was also recorded. The sighting of Silver forget me not was reported only from the Chinnar Wildlife Sanctuary in Idukki district of the State. The three-day survey was done jointly by the Forest and Wildlife Department in association with the Ferns Nature Conservation Society (FNCS).
• The diversity of butterflies was very low in the forest areas where alien invasive plants such as Senna spectabilis invade other endemic plants, whereas the diversity was very rich in areas where plants such as Mikania micrantha and Lantana camera remained dominant.
• The sighting of 191 species of butterflies is an evidence of a healthy butterfly habitat in the region, but the degradation of the riparian forest in many part of the region may adversely affect the butterfly habitat in the near future.

Significance of survey

• As the study on butterflies was also the study on nature and climate change, the survey report would help the Forest Department to prepare a forest management plan in the region in the coming years,.

Butterflies as bioindicator

• Butterflies are increasingly being recognised as valuable environmental indicators, both for their rapid and sensitive responses to subtle habitat or climatic changes and as representatives for the diversity and responses of other wildlife.
• Butterflies react extremely quickly to even minor changes in the environment, making them both a good indicator of biodiversity and providing an early warning system for other reductions in wildlife. As a result, they are now the best-monitored group of insects in the world.
• Butterfly cannot survive in the presence of the toxic gases like sulphur di-oxide, carbon di oxide, carbon mono-oxide, etc. emerging from the increasing use of technology. So, the study of characteristics of butterfly can make us aware of the environmental pollution.

What makes buterflies good indicator

• Butterflies have short life cycles and thus react quickly to environmental changes.
• Their limited dispersal ability, larval foodplant specialisation and close-reliance on the weather and climate make many butterfly species sensitive to fine-scale changes. Recent research has shown that butterflies have declined more rapidly than birds and plants emphasising their potential role as indicators.
•  Unlike most other groups of insects, butterflies are well-documented, their taxonomy is understood, they are easy to recognise and we have a wealth of information on their ecology and life-histories.

Impact

•  Good indicator of biodiversity and providing an early warning system for other reductions in wildlife
• Birds plan their whole breeding season around when caterpillars will be most abundant. If the butterfly and caterpillar numbers are depleted then there's not going to be a lot of food for developing chicks
• Plants will also be affected. Butterflies are a major pollinator of both wild and cultivated plants. Without them and other important pollinating insects flying around, there will be a significant decline in viable seed produced.