First person – Baheerathan Murugavel

Baheerathan Murugavel

Describe your scientific journey and your current research focus

I am a bioengineer turned bat biologist who started my scientific career with a bachelor's degree in biotechnology and then moved into master's degree majoring genomics. I was introduced to animal behaviour and bats during my master's dissertation which marked the starting of my career in bat biology, especially their sensory ecology. My research focus in the last 8 years has been on the sensory ecology of this non-echolocating family of frugivorous bats (family: Pteropodidae). During my dissertation, I investigated the role of olfaction in social communication in the harem-forming fruit bat Cynopterus sphinx. Using olfactory two-choice experiments, I found females could distinguish males based on their scents. Next, for my PhD, I compared light-based flight behavior in three sympatric fruit bat species – the cave-roosting Rousettus leschenaultii, foliage-roosting Cynopterus sphinx, and the tree-roosting Pteropus giganteus/medius. I investigated how their flight activity with respect to ambient lighting (natural and artificial) is linked with the structure and function of their visual system. I found species-specific effects of both natural and artificial lighting on their flight behavior. I also found that the ability of their eyes to resolve details in a visual scene was more linked with their body sizes than ecology and ambient light exposure. Overall, my research so far has been exploring different aspects of the sensory and movement ecology of fruit bats that share landscapes with humans.

Who or what inspired you to become a scientist?

A drive for understanding the natural world was always there in me since childhood. I identified my interests in basic sciences during my biology classes at school and I am fortunate to have gotten excellent science teachers and mentors through the years who nurtured my curiosity right from my schooling until my PhD. My teachers and mentors are my first inspirations. Next, I am always inspired by the curiosity and scientific thirst of my fellow classmates, colleagues, seniors, and juniors in college and during my PhD. Before starting my PhD, the books and popular science works of (the late) Dr Carl Sagan aspired me to become a scientist and a science communicator. Next, at a personal level, I was inspired by the scientific contributions of (the late) Professor S. Krishnaswamy and (the late) Professor M. K. Chandrashekaran, the founding forefathers of the Department of Animal Behaviour and Physiology, School of Biological Sciences, Madurai Kamaraj University, India, where I did my master's degree. Their farsighted thinking and experimental designs on a variety of study systems seeded the motivation in me to start studying an animal like bats.

How would you explain the main finding of your paper?

Flying foxes are large fruit-eating bats that are efficient long-range seed dispersers and pollinators in tropical landscapes. By attaching solar-powered GPS transmitters on Indian flying fox males, we show a difference in their nightly movement and home range that might be linked to their experience and age. Next, we asked if individuals show any difference in their nightly movement among different moon phases. This is because flying foxes lack the ability of echolocation and predominantly rely on their sense of smell and light-based visual cues for their nightly movement. We found that the overall nightly movement by tracked individuals did not differ significantly between moon phases. Following, we wanted to know if the resource availability in the landscape has an influence on the flight directions of this species on a nightly basis. In 61% of total tracked nights across individuals, the first foraging site was within 45° of the emergence direction. At the colony-level, scan-based observations showed emergence flights were mostly in the northeast (27%), west (22%) and southwest (19%) directions collectively which could potentially be related to the distribution of foraging resources. Overall, our results suggest that the movement patterns of Indian flying foxes are little affected by variation in ambient light levels, while resource location and availability determine emergence flight directions.

What are the potential implications of this finding for your field of research?

Indian flying fox is the only flying fox species distributed in the Indian mainland and our study is the first movement-based study on the species the Indian landscape and the third study overall. In addition, our study has investigated the influence of moon phases and how resource locations might affect the nightly movement patterns of this species. Our findings help in understanding the effects of ambient light and resources in the landscape on the flight patterns of the species. The Indian flying fox is a city-dwelling species and shares a significant amount of space with human habitation. An understanding of their movement patterns in such landscapes is important, especially from a sensory ecological point of view and our findings provide insights into that. These findings are useful in further estimating the possible effects of human-induced stressors such as artificial lighting at night, habitat destruction, etc. on the movement and sustenance of the species in urbanized habitats. This is crucial to develop strategies to have a healthy bat-human coexistence in such landscapes.

Which part of this research project was the most rewarding?

The fieldwork involving trapping the individuals was a challenging and rewarding experience for me. Despite being the largest and most widely distributed fruit bat species in India, the Indian flying fox was one of the most challenging species to capture using conventional trapping methods used for other bats. With help from flying fox experts, local fishermen, and farmers, I devised a customized netting protocol using bamboo poles and nylon threads which finally worked after a few months of standardization. These customizable and cost-efficient capture nets formed the basis for conducting a movement ecology study on the species. I and this project had enough scientific and funding support from my supervisors and collaborators to experiment with new methodologies during my fieldwork which eventually helped me in achieving my project goals in a rewarding manner.

What do you enjoy most about being an early-career researcher?

I am just out of my PhD life and starting to explore available options to continue research in animal behaviour. I personally feel excited to be conducting research in an era where technology is growing at a rapid rate. I enjoy exploring different interdisciplinary approaches that exist in the current day to address certain questions from multiple angles. Being interested in studying animal behaviour, I feel it is important to be aware of and understand the available tools and techniques that can be applied to address my research questions of interest. I think being an early career researcher provides me a scope for this hands-on learning experience backed up by my current skill sets from my PhD.

What's next for you?

I have just completed my PhD and I am currently looking for postdoctoral positions. My broader theme of interest is sensory ecology and movement behavior and I look forward to expanding my knowledge and experience in bats and other model systems. In the longer run, I aspire to start my own research group addressing issues related to human-animal coexistence in urban spaces with a primary focus on sensory and movement ecology. I look forward to using my skill set to move forward in my career path in both the shorter and longer terms.