- Butterflies are some of Bangladesh’s most prolific pollinators and important ecosystem indicators.
- Insects, including butterflies, are especially vulnerable to climate change and other human-caused ecosystem changes.
- Despite the increasing threat of extinction, few legal protections or conservation initiatives focus on preserving butterflies and other insects.
- South Asian scientists are engaging communities in citizen science to garner attention to often-overlooked butterfly species.
In the dark undergrowth of mangrove forests, an anthology of color stirs. Flickers of turquoise rise like exhales from the brackish marshlands, and flashes of sunset orange spark alive in the shadows.
The Sundarbans mangrove forest in Bangladesh and India is largely known as one of the last remaining habitats for the Bengal tiger (Panthera tigris tigris), but the coastal groves also thrum with a wealth of smaller animals, including 37 known species of butterfly. The small stature of these butterflies belies their importance; they pollinate flowering plants and nourish the birds that flit through the canopy, ultimately supporting the health of the entire forest ecosystem.
But butterflies in the Sundarbans and throughout South Asia are at increasing risk of extinction, mimicking a global trend that some experts have nicknamed “the insect apocalypse.” By some estimates, 250,000-500,000 insect species have gone extinct in the past 150 years, and many more are now on the brink of survival. Climate change and urban development form the largest risks, along with the minimal legal protections and large-scale conservation initiatives focused on butterflies and other insects.
“If my government is not aware, [butterfly species] will be lost. It will be coming in probably 10 years because climate change is thriving,” said Monwar Hossain, a professor and lepidopterist at Jahangirnagar University in Bangladesh.
The unique beauty and vibrancy of Bangladesh’s butterflies first attracted Hossain’s attention nearly three decades ago. Over his career, Hossain has observed the climate crisis unfold through record-breaking heat waves, severe cyclones and accelerating sea level rise, and his research often focuses on the unique ways these changes impact Bangladesh’s 400+ endemic butterfly species.
Insects, including butterflies, are cold-blooded, so they are unable to adjust to changes in temperature as easily as mammals and birds. This puts them at special risk during short-term weather events like heat waves as well as from changes to long-term temperature trends. Many insects are also unable to migrate long distances to escape changing climate patterns or storms. The reliance of pollinators like butterflies on flowering plants adds an extra dimension to their vulnerability, as even small changes in the flowering season can spell starvation for the unlucky nectar gatherers.
Despite these risks, Bangladesh currently has few protections for butterflies, such as protected areas or bans on collecting and trading specimens. Hossain contrasted this deficit with the international attention and surplus of funding dedicated to large mammals, such as tigers.
“Every animal has its own right to survive, so I don’t want to compare the butterfly, but in my country’s context, millions and millions of dollars [are used] for the tiger,” Hossain said. “Sometimes we say to the government, why not include the butterfly?”
A 2021 study determined less than 2% of the ranges of Bangladeshi butterflies were included in protected areas. The study’s author, Shawan Chowdhury, was far from surprised by the results. A Bangladeshi native, Chowdhury has witnessed the entomological oversights of conservation and development decisions in South Asia firsthand.
“Nothing is actually happening with insect conservation in Bangladesh,” Chowdhury said.
Part of the issue, according to Chowdhury, is a lack of prior research. Animal conservation is typically predicated by years, if not decades, of careful documentation and monitoring. Before politicians write laws to protect animals, scientists are tasked with providing evidence that shows if and what kinds of protections the animals need.
Recent years have seen a few promising additions to South Asia’s collection of entomological research. The International Union for Conservation of Nature included butterflies for the first time in its most recent Bangladesh report, thanks in large part to Hossain, who authored the butterfly section of the report. Chowdhury has also contributed several scientific articles, including a four-year observational study on butterflies in Bangladesh’s capital city of Dhaka. But the entomology community is still playing catch-up.
Chowdhury pointed out that naturalists have surveyed birds for centuries; scientists can now use these historical accounts to estimate how populations have changed over time. For insects, particularly those in South Asia, “there is no account.” Making an accurate account from scratch takes years of consistent observation, which can be both time- and labor-intensive.
Nitin Ravikanthachari observed a similar problem in his home city of Bengaluru, India.
“You can literally count the number of people [in India] studying butterflies on one hand,” he said.
Ravikanthachari spent much of his adolescence prowling the gardens and parks of Bengaluru, camera in hand, and even after beginning a university degree in biology, he often met up with fellow photographers to walk the city and photograph butterflies. As his interest in lepidoptery grew, Ravikanthachari realized how little scientific attention had been dedicated to the subject, and he decided he wanted “to do something more concrete” to address this gap and call attention to the importance of butterflies.
In 2012, Ravikanthachari and three other amateur lepidopterists founded the Bangalore Butterfly Club (BBC). Rather than relying on large institutions and universities to generate information about their city’s butterflies, the BBC started conducting their own research walks to count the number and species of butterflies in the city. Over time, they could use this data to establish trends and gage the health of butterfly populations.
The initiative was massively successful.
To date, the BBC has catalogued more than 170 species of butterflies in Bengaluru, including 14 formerly unknown species. More than 400 members attend research walks, educational events and an annual butterfly festival hosted by the group. Ravikanthachari even rediscovered a species thought to be extinct after a 120-year absence from scientific records.
Ravikanthachari said they are now trying to export the BBC’s success to other cities in India, and Chowdhury is hopeful a similar model could prove useful in Bangladesh, especially in heavily urbanized areas where development pressures catalyze existing risks related to climate change.
“Population is actually a power, but we are not using that,” Chowdhury said.
He pointed to apps like iNaturalist as a way to not only provide more opportunities for sightings to be recorded and to build a species database, but also to educate the public on the importance of butterflies and other insects.
Hossain has also integrated community education and citizen science into his research. His library of scientific studies is supplemented by brochures and children’s books, and his lab began hosting an annual butterfly fair with performances, competitions and educational activities in 2010. The Butterfly Park and Research Centre, opened in 2015, not only breeds butterflies for research purposes, but also functions as a public garden on the Jahangirnagar University campus.
Through these opportunities to interact with and learn about butterflies, Hossain said he sees more and more young people becoming interested in the environment and conservation.
“Once they see the butterfly, the climate change, the forest, they get it,” Hossain said.
Ultimately, he hopes the growing community of citizen scientists, environmental advocates and butterfly enthusiasts will translate into more scientific research and legislation about butterflies. The more people who become interested in butterflies, he explained, the more opportunities there are to continue the work he started 28 years ago.
“I’m just a worker. I’m a worker,” Hossain said. “I think that life is very short, so every [person] does some significant work in the world, for the nature, for his life or other things.”
Whether it be the students in his lab, lawmakers in Bangladesh’s Parliament or young children visiting the Butterfly Park and Research Centre for the first time, Hossain is hopeful that the next generation will learn from his own experiences and choose to dedicate some of their life and work to researching and protecting South Asia’s butterflies.
Banner image: A common Jezebel (Delias eucharis). Image by Venu Gopal via Flickr (CC BY-NC-ND 2.0).
This story is published through a collaboration between Mongabay and the University of Montana’s School of Journalism. Students traveled to Bangladesh in May 2024 to document the effects of climate change. You can read more about the program here.
Climate change is hammering insects — in the tropics and everywhere else: Scientists
Citations:
Hossain, M (2014). Check list of butterflies of the Sundarbans mangrove forest, Bangladesh. Journal of Entomology and Zoology Studies 2014; 2 (1): 29-32. Retrieved from https://www.entomoljournal.com/vol2Issue1/Issue_jan_2014/10.1.pdf
Chowdhury, S., Alam, S., Chowdhury, S. U., Rokonuzzaman, M., Shahriar, S. A., Shome, A. R., & Fuller, R. A. (2021). Butterflies are weakly protected in a mega-populated country, Bangladesh. Global Ecology and Conservation, 26, e01484. doi:10.1016/j.gecco.2021.e01484
Chowdhury, S., Shahriar, S. A., Böhm, M., Jain, A., Aich, U., Zalucki, M. P., … Fuller, R. A. (2021). Urban green spaces in Dhaka, Bangladesh, harbour nearly half the country’s butterfly diversity. Journal of Urban Ecology, 7(1). doi:10.1093/jue/juab008