“Shawan, you can never pass the 10th Standard!” I still remember people saying that. As a boy who preferred to run around in the lush nature of Bangladesh, and who played cricket, soccer and many other sports, education seemed a nightmare. Ultimately, I failed eight out of 12 subjects in Class Seven and became the last boy of the village school. Everyone concluded that I would neither gain a proper education nor enjoy a delightful future. My parents sent me to my mother’s family in India, where I stayed for 1.5 years, but nothing changed. After I returned, I decided not to go back to India by any means, so my only option was to start studying. That was a major turning point in my life.
The beauty of biology
Although my passion for nature had started in my childhood days when I preferred roaming around forests and open fields, I never considered becoming an ecologist before the final year of my undergraduate degree.
In Bangladesh, there is little chance for students to decide which subjects they are going to study; everything depends on their university admission test score. Somehow, I got Zoology. I decided to retake the university admission test and waited another year, yet still I was selected for Zoology. I obtained very low scores in Biology, but I started working hard to understand the basics. I realised that I was incapable of learning in large groups – and that changed my life. From then on, instead of attending long, boring classes, I started watching YouTube videos and reading blog posts. Finally, I grasped the beauty of the subject.
On 20 December 2013, I attended a butterfly photography walk organised by a Facebook group – and spotted over 50 species in just a few hours. I was fascinated to observe numerous colourful butterflies in a small urban green space. I went back the following day and spotted many more species, and then and there I decided to work on insect conservation. Over the next three years, I surveyed that park and two other green spaces weekly. I discovered that Dhaka, one of the world’s most polluted and densely populated cities, harbours over 45% of the national butterflies of Bangladesh, of which 40% are nationally threatened. These works are published in the Oriental Insects, and the Journal of Urban Ecology.
During my field surveys, I noticed that some butterfly species (e.g., Vanessa cardui) were discretely recorded in different parts of Bangladesh. Going through published studies, I learned about their fascinating migratory movement. I decided to work on the ecology and conservation of migratory butterflies as a PhD project. I am so fortunate to have Professor Rich Fuller and Professor Myron Zalucki as my PhD advisors.
While 12% of vertebrates are migratory, the migration of insects is much less understood, despite its potentially huge importance to ecological resource flows and ecosystem services globally. My PhD reveals that migration is much more widespread in butterflies than previously realised, extending far beyond the well-known examples of the monarch and the painted lady. This research is now published in the Biological Reviews.
I use climatic niche models to estimate that most migratory butterflies undergo strong seasonal variation in their distribution and that such seasonal switching in habitat suitability is most prominent at lower latitudes and in the warmer parts of the world. Sadly, one in seven migratory butterflies could be at an elevated risk of extinction. This research is now published in the Ecology Letters.
My PhD also investigates one of the most remarkable range expansions of recent decades, that of the tawny coster Acraea terpsicore. I show that, while it is expanding naturally, the tawny coster butterfly is maintaining its native climatic niche. This butterfly is expanding its range in Australia by 135 km per year. This research is now published in the Diversity and Distributions.
My PhD delves into the protected area performance of Bangladeshi butterflies, too. I reveal that only a tiny fraction, <1.5%, of the geographic range of butterflies in Bangladesh overlaps with protected areas. Despite the minimal protected area coverage overall, overlap with protected areas was slightly higher for threatened butterflies, especially in the case of the Critically Endangered and Endangered species. This research is now published in the Global Ecology and Conservation.
Finally, I assess the conservation status of about 100,000 insect species in protected areas. I discover that the overall protected area coverage is <20% for insects; however, one in three species have <10% coverage, and nearly 2000 species have no coverage at all. Three in four insect species are inadequately covered by protected areas.
Overall, this research has helped to improve our understanding of the prevalence and characteristics of migration in insects and highlight some of the major shortfalls in global conservation efforts for insects in a changing world. Not a bad achievement for a boy for whom education was once a nightmare!
If anyone is interested to start a discussion on any topic, please feel free to contact me.