Data and script for Apodemus behaviour-metabolism covariation analysis

Energy is a central resource for life, but animals’ energy budgets are limited by their ability to collect, process and redistribute energetic assets to diverse functions, including behavior. Yet none of the existing bioenergetic models unequivocally explain behavioral variation, suggesting that they are not mutually exclusive, or that they are incomplete and overlook important processes. To describe a means by which an endotherm regulates its metabolism and behavior in varying environments, we simultaneously analyzed several components of energetic budgets. To accurately assess the costs of body maintenance and thermoregulation, and locomotory movement and shyness of wild mice, we measured resting metabolism at different temperatures, and repeatedly quantified basal metabolic rate (BMR) and behavior. We found that individuals with high BMR are bolder, providing support for ‘performance’ mechanisms. We also, however, identified a trade-off between high metabolic cost and boldness: individuals with higher thermoregulation-induced metabolic rate, above their basic maintenance costs, are shyer.