Spatial and Behavioral Dynamics of Socially Isolated Wild Pigs Following Sounder Removal

Abstract

Effective management of invasive wild pigs (Sus scrofa) requires understanding how individuals respond to social disruption. We GPS-collared 18 female wild pigs to evaluate spatial behavioral changes following partial sounder removal via trapping. Over a 30-day post-trapping period, pigs remained close to trap sites (mean: 1.2 km; max: 6.4 km), showed stable range sizes, and limited dispersal. Using net squared displacement modeling, we classified daily movement into six behavioral strategies and evaluated time allocation as well as the influence of social structure and composition. Wild pigs showed a clear temporal progression from structured, cautious behaviors (encamped, semi-roundtrips) to unstructured, more flexible behaviors (wandering, exploring), with a transition occurring around days 18-20. Lone pigs were influenced by social composition: individuals from adult- and female-rich sounders initially exhibited strong site fidelity following trapping but gradually shifted towards more exploratory behaviors over time. These results suggest that lone survivors often remain in or return to trap site areas, creating a critical window for follow-up efforts. Understanding spatial behavior after disturbance can improve control strategies and reduce the risk of disease spread.