3056
ashankar @ tifrh . res . in
H-2, PI-105
Personal Webpage
Research Overview
I am curious about how animals manage their energetic needs under extreme circumstances. At TIFRH, our lab will be studying animals that are potential heterotherms (can modulate their body temperature to save energy). For my PhD at Stony Brook University in New York, I studied hummingbirds, the tiniest birds, in the cloud forests of Ecuador and the deserts of Arizona, to understand how they manage to stay alive on a daily basis. They spend energy incredibly quickly, and barely have any backup energy stores in the form of fat. They are therefore almost always a few hours from death. Their energy management strategy that most captured my attention was their use of daily torpor- an energy saving state similar to hibernation when they drastically lower their metabolic rate and their body temperature and save an average of 86% of energy every hour. In a postdoctoral position at the Cornell Lab of Ornithology, I used transcriptomics to look at how gene expression changed in various tissues during torpor in these hummingbirds. What physiological processes keep them alive when they are functioning at 10-20% of their normal metabolism? Which physiological and cellular processes are deemed ‘essential’ in sleep vs. torpor? We will be extending this work to tropical Indian species, integrating whole animal energetics, thermoregulation, and transcriptomics with a range of free-living animal species, starting with birds. We will be measuring their energy budgets across habitat types, and looking for heterothermy as an energy management mechanism in a range of species.