energetics

Energetic costs of locomotion. ATP (adenosine triphosphate) is the currency of life. Nearly every action an animal takes — from contracting a muscle to firing a neuron — is powered by the hydrolysis of ATP to ADP and inorganic phosphate. This creates a fundamental closed loop: ATP fuels the behaviors animals use to acquire food, while the processing of that food regenerates ATP. For this loop to sustain life, the energy gained from nutrients must exceed the energy spent acquiring and processing them — leaving enough surplus for growth, reproduction, and the occasional indulgence. Animals have presumably evolved strategies to optimize this balance, and disruptions to either side of the equation (nutrient availability or ATP-generating capacity) can have profound behavioral consequences. Understanding why animals do what they do — and how such behaviors may have evolved — therefore requires grappling with the energetic costs and constraints that shape them.

A major focus of the lab is understanding the energetics of animal locomotion — arguably the most ATP-demanding behavior most animals engage in. We study this across a diverse range of invertebrate taxa, including dragonflies, hawkmoths, bumble bees, monarch butterflies, cockroaches, and fruit flies, allowing us to ask both species-specific questions and broader comparative ones about how body size, morphology, life history, and environmental stressors shape the energetic cost and efficiency of movement. Many of these species are also pollinators, migrants, or ecological indicators, meaning that understanding their locomotor energetics has direct relevance to conservation and agricultural contexts — particularly as anthropogenic pressures such as pesticide exposure, habitat loss, and climate change increasingly challenge their ability to move, forage, and reproduce. A key tool in this work is respirometry — the measurement of oxygen consumption and/or CO2 production as a proxy for metabolic rate — which we use in both resting and actively flying or running animals. Because access to commercial respirometry equipment can be a significant barrier for research and teaching alike, we are also actively developing lower-cost respirometry solutions, with the goal of making quantitative energetics accessible to a wider range of researchers and students.