Energy Budgets of Ectothermic Vertebrates

Ecological energetics provides a unifying focus for ecological studies. Heat energy budget analysis is used to predict the body temperatures of animals and their microclimatic requirements. Climate space diagrams, transient energy balance models and operative environmental temperature models predict daily and seasonal activity patterns, predator-prey interactions and energy requirements of vertebrate ectotherms. Food energy budget (resource allocation) models are used to investigate the life history processes of fish, amphibians and reptiles. Heat energy budgets and food energy budgets interact through their effects on body temperature and metabolism. Coupled heat, food and mass balance equations can serve as a unified energy budget model and are useful in determining limits on the energy available to an animal for growth and reproduction. Bioenergetic models have been successfully applied to some reptiles and fish. Complete energy budgets are now needed for other ectothermic vertebrates.