Diel patterns of movement reveal temporal strategies during dispersal

Abstract

Movement is a key part of life for many animals. However, a number of temporal constraints, from changes in light and temperature to varying risks of predation, limit not only where animals can move, but also when. Such constraints are likely to be most pronounced when animals must make large displacements, as is the case when individuals disperse. However, little is known about how dispersers overcome temporal constraints on movement, despite significant implications for the success of dispersal. We outline a general framework for identifying the strategies animals use to achieve large displacements in the face of constraints on when and how to move, which we predict should follow one of three patterns: increasing their movements during those times when they typically move more, uniformly across the day, or when they previously moved least. Using high-resolution GPS tracking of dispersing and resident vulturine guineafowl, Acryllium vulturinum, we show that dispersers expressed the greatest increases in movement at the same times of day that they moved most prior to dispersing. Our results suggest that individuals face the same ecological constraints during dispersal as they do in daily life and achieve large displacements by maximizing movement when conditions are most favourable.