From metabolism to coexistence: Understanding animal movement and community dynamics through energy

Leonna Szangolies, Florian Jeltsch, Lewis G. Halsey, Cara A. Gallagher 

To counteract ongoing biodiversity loss due to global change, we need a deeper understanding of when and how species coexist. Recent work has begun to uncover mechanistic links between species coexistence and the movement of individual animals, revealing how individual behaviour can shape community dynamics. This movement behaviour is both motivated by and constrains an animal’s energy state, which in turn drives organism fitness and species interactions, for example by minimizing energy costs or maximizing energy intake. Advancing our understanding of individual energetic mechanisms can therefore reveal key drivers of coexistence. Here, we propose a conceptual framework linking animal energetics, movement behaviour and coexistence to explore how energy fluxes drive movement, mediate species interactions and shape community dynamics, extending former theories that address subsets of these relationships. Energetics is an important process influencing whether, how, where and when animals move, and underpins both equalizing (e.g., similar energy balances among species) and stabilizing (e.g., energy costs that limit large populations) mechanisms of coexistence. By synthesizing insights from community ecology, movement ecology and ecophysiology, we highlight how the integration of these fields reveals a fundamental set of interconnected mechanisms shaping species coexistence. We advocate for this mechanistic framework to improve our understanding of diversity dynamics and predictions of the impacts of environmental change on coexistence and biodiversity. We call for the development of interdisciplinary methods to test predictions evolving in this area and provide examples of how this framework can be applied to advance understanding across varied ecological systems.