Wild boar scavenging activity before vs. after wolf recolonization in a Mediterranean protected area

The trophic plasticity of the wild boar Sus scrofa allowed this ungulate to spread worldwide. The ability to adapt to different environments is one of the main factors that has favoured the recolonisation across Europe of its main predator: the wolf Canis lupus. Being an omnivorous species, the wild boar may establish complex relationships with the wolf, due to the consumption of carcasses of wolf prey. We considered the trophic relationships between these species focusing on the changes in the use of ungulates by the wild boar before vs. after wolf recolonization in a coastal area of Italy. Plant material composed c. 90% of the diet of wild boar, followed by invertebrates and mammals, but no hair of ungulates was detected prior to wolf recolonization (1991-1994, N= 3748 faecal samples analysed). Conversely, deer hair was found in 13 samples of 1261 collected in 2023 after wolf recolonization. Wolf diet was dominated by the use of wild boar (57% of occurrence), followed by 23% of fallow deer Dama dama and roe deer Capreolus capreolus combined in 2023. The relatively modest importance of deer carcasses in the diet of wild boar might have been limited by a high perceived predation risk and/or by the low availability of deer species compared to wild boar prey for wolves, emphasizing the context-dependent nature of wolf-prey relationships. However, these results indicated that deer carcasses provided foraging opportunities for the wild boar, suggesting increased trophic possibilities for this suid due to the wolf presence.