The significance of the domestic pig, Sus scrofa, to prehistoric Polynesians is hinted at by its inclusion among the species that they transported with them as they colonized Oceania. However, archaeological data reveal a pattern of pig distribution far more extensive in prehistory than at historic contact. Domestic mammal extirpation is a phenomenon apparently unique to prehistoric Polynesia. Although well recognized, the local extinction of domestic pigs in Polynesia prior to European contact has yet to be satisfactorily explained. Earlier accounts attributed the patchy distribution of pigs across the Island South Pacific to intentional extermination by their Polynesian keepers. More recent approaches seek to understand the disappearance of these animals within a biogeographic and ecological framework. Here, I test the hypothesis that the success of pig husbandry is correlated with ecological variables and demonstrate that the likelihood of pig extinction increases with decreasing island size.