Evidence of hybridization between wild boars and feral pigs (Sus scrofa) from Argentina: implications for the success of the invasion process

Hybridization between individuals of different subspecies play an important role in evolutionary processes. These crosses in exotic species have been reported to generate effects such as alterations in the local gene pool, enhance genetic variability, morphological and coat colour changes, which gives it a greater adaptive potential and, thus an increase in invasiveness. Sus scrofa do not escape this scenario, since cases of hybridization between wild boars and their domestics have been reported in several European countries. In Argentina, S. scrofa is one of the most concerning invasive species, and distributed throughout most of the country, generating contact sites between the wild (wild boar and feral pig) and domestic forms. Recently, genetic studies suggested the possible hybridization between wild boars and feral pigs from Argentina, so the aim of this study was to determine for the first time if such hybridization occurs, as well as to quantify the genetic diversity in a population of feral pigs from the Buenos Aires province, through molecular markers MC1R, NR6A1, control region and microsatellites. For this purpose, N = 161 samples were collected at 34 sampling sites. Through the markers MC1R, NR6A1 and the mitochondrial control region, hybrid individuals and pure wild boars were found. On the other hand, the diversity indexes evaluated with the control region and microsatellites were higher than expected. Therefore, this work reports for the first time the effective cross between wild boars and feral pigs from Argentina, as well as a high genetic diversity, which could positively contribute to the effect as an invasive alien species.