Metabolic plasticity drives mismatches in physiological traits between prey and predator

Abstract

Abstract Metabolic rate, the rate of energy use, underpins key ecological traits of organisms, from development and locomotion to interaction rates between individuals. A warming world, acting through the temperature-dependence of metabolic rate, is expected to alter predator-prey dynamics. Yet, there is very little real-world empirical evidence on the effects of warming on trophic interactions. We measured the respiration rates of the aquatic larvae of three insect species, from populations experiencing a natural gradient of temperatures in a large-scale mesocosm experiment. Using a mechanistic model we predicted the effects of warming on predator-prey interaction rates among these taxa. We found that differences in metabolic plasticity of the three species likely lead to mismatches in the temperature-dependence of their relative velocities, resulting in altered predator-prey interaction rates. We conclude that species-level differences in metabolic plasticity likely plays a key role in changing trophic interactions and food web dynamics in a warming world.