Wild boar (Sus scrofa) harvesting using the espera hunting method: side effects and management implications

Harvesting of wildlife by man has been linked to demographic and evolutionary impacts in many populations. We investigated the sex ratio and age class structure in hunting bags of wild boar harvested by espera - nocturnal single hunt at bait - during four hunting seasons in Alentejo (Portugal). In addition, we assessed whether the hunting method is a significant predictor of the probability of harvesting an animal of a particular gender, of particular age class or of a particular combination of these two attributes. We found that the espera hunting method allows very selective harvesting regimes and, thus, it seems a highly effective population management tool. Removing a large proportion of adult males, however, may bias the population sex ratio towards females, reduce male life-expectancy and raise the degree of polygyny. Our results suggest that recruitment rates are resilient to this skewed sex ratio, and possibly the higher proportion of females in the adult population may even increase productivity