Wyoming Pronghorn and Elk Movement Project

Project Overview

The spatial variation and temporal predictability of resources, such as nutritious forage, are predicted to determine where and when animals move across the landscape. Animals are predicted to be strongly migratory in environments where resources are heterogeneously distributed across space but predictable across time, such as plains and mountainous terrain where there are elevation and precipitation gradients. Conversely, animals are predicted to be strongly resident in environments where resources are homogenous across space yet temporally predictable, such as deserts. Moreover, other environmental factors, including human activities and winter conditions, may influence the migratory behavior of animals. Via a large collaboration, Becker et al. 2025 used GPS collar data from 7 populations of pronghorn and 12 populations of elk across the state of Wyoming to understand whether the spatiotemporal distribution of resources and additional environmental variables shape the migratory behavior of ungulates, including the likelihood of being strongly migratory, resident, or nomadic. Consistent with ecological theory, pronghorn and elk were more likely to be resident in environments where resources varied less across space and more across time. Other environmental variables, including winter severity, also influenced migratory behavior. Specifically, elk were less likely to be resident amid severe winters, suggesting that heavy winters could drive elk to move across the landscape. These findings support the hypothesis that the spatial variation and temporal predictability of resources strongly drive migratory behavior in temperate ungulates. Click here to read the published manuscript in Proceedings of the Royal Society B.