The Physics of Conservation

Personal Essay | Blog

August 2019

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Starting out high school, I was determined to become a biologist and work in an ecological backdrop. Owing partly to the dry and mundane biology curriculum during high school, and partly to the enigmatic discipline of physics, I ended up pursuing an undergraduate in Physics at Ashoka University. As first year came to an end, I drowned myself in an existential crisis dwelling on the same question— How does this physics buff chase his passion for the environment and ecology, while still doing physics?

My fondness of the former and a bond with the Spiti valley in the Himalayas led me to closely follow the high altitude research program of the Nature Conservation Foundation (NCF). This program has been a pioneer of snow leopard research in the valley. They were currently studying prey-predator dynamics and its implications for the livestock rearing communities. With a typical first-year enthusiasm, I straight-up wrote to the founder of the organization, Dr. Charudutt Mishra, expressing my interest. To my utter good fortune, Dr. Mishra happened to be visiting my university in a matter of days to deliver a talk on the very projects that I was interested in. I bumped into him during lunch, and my unanswered email was responded to with an invitation to have lunch with him!

Fast forward to summer, I find myself in Bharmour, Himachal Pradesh, interning under Ms. Devika Rathore for a project to estimate the population of snow leopards in the state. It was part of a global project by the Snow Leopard Trust (SLT) to map out the snow leopard populations across the World. This was a pioneer study in the new terrain and I was absolutely thrilled about the challenges we were to witness in that process.

Population estimation studies often use a capture-recapture method. In a nutshell, you take the entire population pool, ‘capture’ a few individuals, tag them, and set them free. After some time, you capture a few individuals again. The probability of capturing the same individual again, indicated by the tag you put on them earlier, allows you to estimate the total population with simple statistics. Our project, however, wanted to also factor in the strongly territorial and free-ranging nature of snow leopards. Thus, we used the Spatially Explicit Capture Recapture (SECR) method. The data for SECR is collected with a spatial array of detectors like camera traps. Individuals can be identified by their unique spot-patterns on their coats. With a mathematical model, one can study the spatial correlations in the capture-recapture statistics and make a robust extrapolated estimate of the population density even for regions that may not have been directly probed by the data collection.

For the fieldwork, it meant that we had to deploy camera traps in a grid in the region we wanted to survey. Subsequently, we had to monitor and remove them over a period of two months. Our first valley in the Bharmour district, the Bada Bhangal from where the river Ravi originates, turned out to be one of the most difficult terrains the team had worked in. Being a new addition, I was overwhelmed at the nature of work, the risks involved and the physical strain. I didn’t set up any cameras in the valley. One time, I even had to stay back alone at a rather spicy location while two other teammates went ahead. It was both disheartening and regretful to be almost a liability. Needless to say, we had an extraordinary team. Our field staff consisted of five members from the Spiti valley who had spent over two decades in snow leopard research. They had the patience and good humor to ease me into the process, never push me beyond comfort, but slowly nudge me towards the edge. While I didn’t start out too well on the camera trapping front, I had the experience of a lifetime living with the people of Dhardi village, where we had the fortune to be offered room and food by them. We crushed pulses on a hand-powered mill, cooked on a traditional mud stove and dined together in the kitchen of Sheela didi, our warm host.

The team’s efforts into helping me get comfortable with the terrain didn’t go in vain. I set up two cameras in that valley later on. We covered the Kugti and Chobia valley in Bharmour, and the Tirthan valley in the Great Himalayan National Park (GHNP) over the next one month. This was truly extra-ordinary for me. I was walking my first ridge lines, climbing vertical tree-lines, crossing huge broken-off glaciers, narrowly escaping black and brown bear territories, sleeping under a rock, and recognizing all snow leopard signs. At one point, Devika and I found ourselves in a blizzard on a ridgeline above 4000 meters while we live-tracked what could possibly have been a snow leopard and her cub. By the time we reached the nearest village, we were completely drenched and freezing, but a kind man offered us shelter, food and fire at his home. It’s hard to describe the gratitude I have towards people like him who helped us on countless rainy days. As for small personal victories, the contentment of clipping a camera trap close after configuring all its settings, and building that mighty stone fortress for it with numb hands in the freezing cold trumps any other feat.


There have been experiences more valuable than moments of adrenaline rush. Working so closely with the forest guards of GHNP, we learnt the shocking realities of conflict between economic practices of the local communities and conservation laws, all in the backdrop of propaganda-driven politics and stagnant rusting bureaucratic institutions. Towards the end of my internship, I worked with Devika on human-wildlife relationships and hunting practices in Bharmour. This had us face to face with hunters, shepherds and local stakeholders not only revealing sensitive information about outlawed practices, but also their own perspective that renders the process of conservation complicated. Without doubt, this allows me to appreciate and acknowledge how nuanced conservation strategies ought to be, and the significance of such research in developing truly effective conservation models.

Throughout these defining experiences, somehow our methodology of research kept me at a certain unease. I couldn’t grasp why we were doing things the way we were. Why were we only deploying cameras in a certain pattern; How were we arriving at certain inter-camera distances; How do we find the right balance between maximizing recaptures and maximizing survey area; How were we to really analyze this data mathematically; How does our small survey region represent all the possible inaccessible snow leopard habitat? It was only when Abhirup, a fellow research associate, and Devika explained to me the mathematics behind SECR, that I realized the incredible extent of scope someone from a physics background could have in the development of mathematical models for ecological research. My time at NCF let me find this confluence of physics, math and ecology, all set in gear to eventually mobilize conservation.