Wild boar in the city: Phenotypic responses to urbanisation

Urbanisation is a global human-induced environmental change and one of the most important threats to biodiversity. To survive in human-modified environments, wildlife must adjust to the challenging selection pressures of urban areas through behaviour, morphology, physiology and/or genetic changes. Here we explore the effect of urbanisation in a large, highly adaptable and generalist urban adapter species, thewild boar (Sus scrofa, Linnaeus 1758). From 2005 to 2018, we gathered wild boar data and samples from three areas in NE Spain: one urban (Barcelona municipality, n= 445), and two non-urban (Serra de Collserola Natural Park, n= 183, and Sant Llorenc delMunt i Serra de l'Obac Natural Park, n= 54). Weinvestigatedwhether urbanisation influenced wild boar body size, body mass, body condition, and the concentration of serum metabolites, considering also the effect of age, sex and use of anthropogenic food resources. Wild boars from the urban area had larger body size, higher body mass, better body condition, and a higher triglyceride and lower creatinine serum concentrations than non-urban wild boars. In addition, urban wild boars consumed food from anthropogenic origin more frequently, which suggests that differences in their diet probably induced the biometric and the metabolic changes observed. These responses are probably adaptive and suggest that wild boars are thriving in the urban environment. Our results show that urbanisation can change the morphological and physiological traits of a large mammal urban adapter, which may have consequences in the ecology and response to urban selection pressures by the species. The phenotypic plasticity shown by wild boars provides both further and new evidence on the mechanisms that allow urban adapter species of greater size to respond to urbanisation, which is expected to continue growing globally over the coming decades. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study investigated the impact of urbanisation on wild boars, showing that urban wild boars have larger body size, higher body mass, better body condition, and different serum metabolite concentrations compared to non-urban wild boars. Urban wild boars also consumed food from anthropogenic origin more frequently. These results suggest that urbanisation can induce adaptive changes in morphology and physiology in wild boars.