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

Abstract

AbstractWhen dispersing, individuals typically have to make large displacements. While previously thought to be costly, recent work has suggested that individuals can largely mitigate these costs by expressing distinct movement strategies—moving faster and straighter—during dispersal. Several studies have also found that individuals express differences in their habitat preferences during dispersal. These preferences often involve an increased use of open habitats relative to their non-dispersing habitat selection, within which individuals typically achieve larger displacements per unit of time. As a result, it has been suggested, but never explicitly tested, that changes in habitat selection could reflect an increased preference for habitats that facilitate greater energetic efficiency in terms of movement. Here, we combine step-selection analysis with models of the energetics of movement to determine whether actively dispersing vulturine guineafowl (Acryllium vulturinum) select different habitats relative to their non-dispersing counterparts, and whether their habitat preferences correspond to a decrease in the cost of transport. Our results confirm that fine-scale differences in habitat preferences expressed when making large displacements during the transient stage of dispersal correspond with an increase in the energetic efficiency of movement. These findings highlight the ability for animals to exhibit adaptive movement strategies across different axes of decision-making (e.g., where and how to move) to overcome different ecological challenges.