Habitat selection during dispersal reduces the energetic cost of transport when making large displacements

Abstract

Dispersal is energetically costly. However, there is now growing evidence that dispersing animals can express distinct movement strategies that allow them to mitigate most of the energetic costs of displacing over large distances. Whilst to date we know that these strategies involve changes in how dispersing animals move, it is unclear whether these changes in movement are facilitated by other components of behaviour--namely changes in habitat selection. Here, we combine step-selection analyses with models of the energetic costs of movement to high-resolution GPS tracking data in terrestrially dispersing vulturine guineafowl (Acryllium vulturinum) to test the hypothesis that dispersing animals should select for habitats that facilitate more energetically efficient movements during dispersal. We find that actively dispersing individuals exhibit increased positive selection for open habitats, especially roads. We then show that moving along roads facilitates straighter, faster movements and results in a more than 33% reduction in the energetic cost of transport relative to other habitat types. Our results confirm that fine-scale differences in habitat selection expressed by dispersers facilitate more energetically efficient movement, expanding our understanding of how animals exhibit adaptive movement strategies across different axes of decision-making (e.g., where and how to move) to overcome ecological challenges.