Demography, peri-urban presence, and male-biased dispersal in an expanding wild boar (Sus scrofa) population in western Spain

Abstract The wild boar ( Sus scrofa ) is a rapidly expanding species that can significantly affect biodiversity and pose challenges for humans, particularly in peri-urban areas. Understanding the processes underlying wild boar expansion is crucial for effective management. In this study, we integrated wild boar demography, urbanophilia, and sex-biased dispersal in the central-western Iberian Peninsula to gain further insights into the expansion process. We analyzed hunting bag data to compare demographic trends between native and newly colonized areas. Sand-filled footprint traps were used to detect seasonal presence in a peri-urban area. Finally, wild boars were genotyped using 16 microsatellite markers, and isolation-by-distance analyses were conducted to assess sex-biased dispersal. We found that wild boar populations were more abundant in native areas, but population growth was primarily concentrated in colonized areas. Wild boars were consistently present in the studied peri-urban area, with higher presence during the food shortage period. Isolation-by-distance patterns were observed for both sexes, but genetic analyses indicated a male-biased dispersal pattern. This multidimensional approach provides key insights for biodiversity conservation and management strategies in the context of wild boar expansion.