Environmental and individual drivers of animal movement patterns across a wide geographical gradient

Abstract

Within the rapidly developing field of movement ecology, much attention has been given to studying the movement of individuals within a subset of their population's occupied range. Our understanding of the effects of landscape heterogeneity on animal movement is still fairly limited as it requires studying the movement of multiple individuals across a variety of environmental conditions. Gaining deeper understanding of the environmental drivers of movement is a crucial component of predictive models of population spread and habitat selection and may help inform management and conservation. In Ontario, woodland caribou (Rangifer tarandus caribou) occur along a wide geographical gradient ranging from the boreal forest to the Hudson Bay floodplains. We used high-resolution GPS data, collected from 114 individuals across a 450000 km(2) area in northern Ontario, to link movement behaviour to underlying local environmental variables associated with habitat permeability, predation risk and forage availability. We show that a great deal of observed variability in movement patterns across space and time can be attributed to local environmental conditions, with residual individual differences that may reflect spatial population structure. We discuss our results in the context of current knowledge of movement and caribou ecology and highlight potential applications of our approach to the study of wide-ranging animals.