The macroecology of community energy use in terrestrial vertebrates

Energy governs all ecological processes and interactions. As an organism’s metabolic rate equates to its rate of energy flow, individual rates can predict community-level functioning. Daily rates of community energy flow for 423 ecological samples representing bats, birds and small mammals were calculated by scaling up from individual metabolic rate. Community energy flows vary with climate only on a per-gram basis, but there are important group-specific biogeographic patterns of community energy use. Bat communities have higher rates of energy flow in the Neotropics, while bird and small mammal communities have lower per-gram rates of energy flow in the tropics. Anthropogenic factors also impact rates of community energy flow, although these differ depending on group, further highlighting the group-specific nature of these patterns. These differences relate to metabolic rate, species richness, abundance, and biogeography, directly linking community energy use to ecology and evolutionary history.