title: How much does it cost to look like a pig in a wild boar group?
abstract: Hybridization between domestic and wild species is known to widely occur and it is reported to be one of the major causes of the current biodiversity crisis. Despite this, poor attention has been deserved to the behavioural ecology of hybrids, in particular in relation to their social behaviour. We carried out a camera trap study to assess whether phenotypically anomalous colouration in wild boar, i.e. potentially introgressed with domestic pigs, affected the hierarchical structure of wild boar social groups. Chromatically anomalous wild boars (CAWs) were detected in 32 out of 531 wild boar videos. In most videos (75%) CAWs were the latest of the group, independently from their age class and group composition. Aggressions by their wild type fellows were recorded in 31.25% videos; by contrast, no aggression among wild type individuals was observed. The lack of camouflage may expose CAWs, and thus their group, to a higher predation risk, compared to wild type groups. This individual loss of local adaptation may increase predation risk by the wolf or detection by hunters, being maladaptive for the whole social group.
authors.affiliation: Department of Science for Nature and Environmental Resources, University of Sassari, Via Muroni 25, 07100 Sassari, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Battocchio
authors.affiliation: Department of Chemistry and Bioscience, Aalborg University, Frederik Bajers Vej 7 H, 9220 Aalborg East, Denmark.
authors.forename: Laura
authors.initials: L
authors.lastname: Iacolina
authors.affiliation: Department of Science for Nature and Environmental Resources, University of Sassari, Via Muroni 25, 07100 Sassari, Italy; CIRSeMAF - Department of Biology, University of Florence, Via Madonna del Piano 6, I-50019, Sesto Fiorentino, Florence, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Canu
authors.affiliation: Department of Life Sciences, University of Siena, Via P.A. Mattioli 4, 53100, Siena, Italy. Electronic address: moriemiliano@tiscali.it.
authors.forename: Emiliano
authors.initials: E
authors.lastname: Mori
mesh_terms: D000374:Aggression; D000818:Animals; D000829:Animals, Domestic / Q000523:psychology*; D006824:Hybridization, Genetic; D012880:Skin Pigmentation; D012919:Social Behavior; D034421:Sus scrofa / Q000523:psychology*; D013552:Swine / Q000523:psychology*
keywords: Aggressive behaviour; Coat colour; Hierarchy; Hybridization; Social units; Sus scrofa