Activity patterns and social organization of wild boar (Sus scrofa L.) in a wetland environment: preliminary data on the effects of shooting individuals

Abstract

The expansion of European wild boar populations has produced an increase in the pressure of this species on Mediterranean marshlands. Aiguamolls de l’Empordà Natural Park in Spain is a protected area with close to 850 ha of Integral Reserves where all human activities, including hunting, are forbidden. Since the beginning of the 1990’s, the wild boar was only an occasional visitor to the reserves, but in the last few years, this ungulate has become a permanent resident, and a high concentration of individuals in the area has lead to the application of population control. Direct observations in the afternoon and at night (with the aid of photon intensifiers) from the periphery of the reserves have allowed the characterisation of 77 wild boar groups and their activity patterns. Most of the animals (70% in spring and 74% in summer) leave the reserves at the beginning of their daily active period, but in autumn and winter, the proportion of the animals that remain inside the reserves increases. The maximum numbers of wild boar inside the reserves occur in autumn, which coincides with the rut, the beginning of the hunting season, and the period when crops are not available in the areas surrounding the reserves. Mean group size was 4.4. The composition of the groups varies seasonally, which is influenced partly by biological events, but also by other factors, such as the removal of some individuals from the population.