Speed is the fundamental constraint of movement, but there is no general consent of what determines an animal’s maximum speed. Here, we provide a universal scaling model of maximum speed with body mass, which holds across movement modes, ecosystem types and taxonomic groups. Our findings, thereby, help to solve one of the most challenging questions in movement ecology over the last decades: why are the largest animals not the fastest? In contrast to traditional power-law scaling, we predict a hump-shaped relationship due to a finite acceleration time for animals. We test our model using extensive empirical data (468 species with body masses ranging from 5.7x10-8to 10,800 kg) from terrestrial as well as aquatic ecosystems.
Results/Conclusions
Our results suggest that this new universal scaling model is substantially superior to traditional power law models. Hence, this mechanistic approach offers a novel concept of what determines the upper limit of animal movement and enables a better understanding of realized movement, dispersal and migration patterns in nature. Moreover, it allows predicting the movement speeds of extant as well as extinct species (e.g. dinosaurs) and thereby helps drawing inferences about their spatial metapopulation structures and potential interactions (e.g. as predator or prey). Overall, our approach provides a simple and powerful tool for predicting the natural boundaries of animal movement and helps gaining a unified understanding of movement across taxa and ecosystems.