Fishes do fear the reaper; Understanding the magnitude and mechanism of the effects of human interactions on animal behavior.

Supervisor: Prof. Kartik Shanker

Thesis Advisors: Prof. Maria Thaker, Dr. Vishwesha Guttal

Humans possess a unique ecology, unlike any other animal. We occupy multiple trophic levels across nearly every ecosystem. Over time, we have played varied roles in the wild: from gatherers to lethal predators, and more recently, as relatively benign visitors. A substantial body of research has explored the effects of humans as “superpredators” on the behavior of animals with which they interact.

As part of my doctoral thesis, I aim to address two core questions:

A) Under what contexts do animals perceive humans as a threat? B) What mechanisms do humans employ to alter animal behavior through their activities?

To answer these questions, my research consists of four chapters, each employing different tools and methodologies. In the first chapter, I conduct a systematic review and meta-analysis to assess the magnitude and context of human impacts on animal behavior. In the second, I use agent-based models to explore how the replacement of apex predators by humans affects the population dynamics and behavior of mesopredators and herbivores. My field observations on coral reefs in the Andaman Islands form the third chapter, where I investigate how the removal of predator fish species influences herbivory within these ecosystems. Lastly, I conduct predator model presentation experiments to determine whether the loss of predators on reefs leads to diminished anti-predator behavior in prey species. Through this research, I aim to deepen our understanding of how humans, in various roles, shape the behaviors and ecological dynamics of the animals around us.