Interplay of physical and social drivers of movement in male African savanna elephants

Abstract Despite extensive research into the behavioral ecology of free-ranging animal groups, questions remain about how group members integrate information about their physical and social surroundings. This is because (1) tracking of multiple group members is limited to a few easily manageable species and (2) the tools to simultaneously quantify physical and social influences on an individual’s movement remain challenging, especially across large geographic scales. A relevant example of a widely ranging species with complex social structure and of conservation concern is the African savanna elephant. We evaluate highly synchronized GPS tracks from 5 male elephants in Etosha National Park in Namibia by incorporating their dynamic social landscape into an established resource selection model. The fitted model predicts movement patterns based simultaneously on the physical landscape (e.g. repeated visitation of waterholes) and the social landscape (e.g. avoidance of a dominant male). Combining the fitted models for multiple focal individuals produces landscape-dependent social networks that vary over space (e.g. with distance from a waterhole) and time (e.g. as the seasons change). The networks, especially around waterholes, are consistent with dominance patterns determined from previous behavioral studies. Models that combine physical landscape and social effects, based on remote tracking, can augment traditional methods for determining social structure from intensive behavioral observations. More broadly, these models will be essential to effective, in-situ conservation and management of wide-ranging social species in the face of anthropogenic disruptions to their physical surroundings and social connections.