Simulated poaching affects global connectivity and efficiency in social networks of African savanna elephants - an exemplar of how human disturbance impacts group-living species

Abstract

Poaching of mature and socially influential African savanna elephants for their prominent tusks alters the structure of their social networks. To learn if targeted poaching affects the functioning (i.e., connectedness and efficiency) of elephant associations, we simulated network formation and disturbance via poaching experiments in one wild and 100 virtual populations. To simulate virtual networks, we built a non-spatial, individual-based model guided by empirical association trends. After poaching of 1) the most mature or socially central individuals or 2) individuals selected at random, we evaluated network connectedness and efficiency. The networks never broke down, suggesting their robustness. Unlike in age-specific deletions, eliminating individuals with the highest topological centrality led to a decrease in network connectedness and efficiency. The simulated networks, although structurally stable, became less functionally resilient when subject to poaching-like stress. Our work may offer new insights into elephant behavior vis-a-vis anthropogenic pressure, and inform conservation efforts focused on translocation of social species or trophy hunting practices.