Why are butterflies soaring higher?

Bishnu Prasad Aryal

Kathmandu, April 8: Climate change comes home to roost. A research, based on Apollo butterfly and Pika hare — the harbingers of global warming — conducted by the World Wildlife Fund (WWF) in the Langtang region of the Himalayas indicate a disturbing trend. Both the insect and mammal have migrated up to 500m in the upper reaches in the last 15 years or so due to the adverse impact of climate change. “Usually Apollo butterflies are found at 3,000m above sea level. Over the years, it has moved 500m above. While, Pika has relocated 100m higher,” Bhaiya Khanal of Natural History Museum told The Himalayan Times. Khanal, an expert on butterflies, was a part of the WWF team that conducted the research. “We can find more evidence of climate changes in the Himalayan region if we conduct an extensive survey. It has been observed that some species of butterfly like Pancy and Crow, which are usually found in the Tarai, are now being sighted in the Valley these days,” he explained. There has been a discernible shift in the life cycle of butterflies as well. Earlier, it would be visible from April to October-November. Now, species like Pieris, Urema and Papillion are found in the wild in March. While, other varieties are making its presence felt in Koshi and Bardiya conservation areas in December. Pieris, which usually lives in 1,800m, has moved up to 2,200m. Of the 14 families, belonging to 650 species, 11 are found in Nepal. Khanal felt that more pronounced changes to global warming would come to light soon. “We are yet to explore many parts, especially the Eastern, Mid and Far-western regions. New species and sub-species will be found in these geographically diverse areas during the course of our study,” he added. At a conservative estimate, the Valley and its fringes are home to around 369 species of butterfly. Of these, around 200 can be found in Godavari and Fulchowki areas. “IUCN has enlisted 20 species as endangered. While, the habitat of 12 is threatened in Godavari. No wonder, some of it haven’t been sighted in the past 15 years. Chinese Windmill is seldom found in the Valley these days,” said Khanal. Dr Dinesh Raj Bhuju, chief, Science and Technology at Nepal Academy of Science and Technology, attributed the drastic changes to global warming. There has been an annual rise in mercury by .06 degree Celsius. “Add to that rampant deforestation, destruction of habitat, haphazard industrialisation and unscientific use of pesticides and insecticides that have gradually sounded a death knell for the rich and diverse fauna in Nepal,” he reasoned. This piece of news was published in THE HIMALAYAN TIMES daily on April 9, 2009.