Canine size, condition and health in wild boars

Abstract

AbstractCanines in wild boar Sus scrofa constitute weapons used in male–male conflict. We analyzed extensive data for the ecological correlates of canine size in several study sites in Extremadura, Spain, to determine their degree of condition‐dependence and their relationship with health status. Boars with relatively large body size had larger canines than small boars. Canine size was larger in estates without livestock, in estates with low population density, and in estates with rich holmoak forest. These findings are consistent with predictions for condition‐dependent secondary sexual characters. Boars with relatively large canines had large spleens for their body size, higher prevalence of Aujeszky's disease and higher prevalence of macroscopic lesions compatible with Bovine Tuberculosis than boars with relatively small canines. Thus, boars with large canines that were likely to be dominant and have differential access to females were in poorer health than boars with small canines. Since the virus responsible for Aujeszky's disease and Mycobacterium bovis are readily transmitted through direct contact during mating, we suggest that there is a sexual conflict over mating. Boars with large canines that are most likely to copulate with sows are also more likely to be a direct cause of transmission of disease to the sows.