Wild boar distribution trends in the last two centuries: an example in Northern Spain

Abstract

An analysis of the Wild boar distribution in the province of Asturias has been monitored from 1800 to 1991. Considering periods of half a century our results reveal a minimum in Wild boar distribution occurring around the middle of the XIXth century and a strong increase in the second half of the XXth century. Several hypotheses have been advanced in order to explain this expansion, including an amelioration of winter temperatures, Wolf population reduction, human depopulation and ageing in rural areas. Comparing each of these data sets with the Wild boar distribution from 1850 until now the results show that only ageing of rural people has evidenced a good relation with the Wild boar expansion occured in these last decades. Obviously, ageing of human rural population led to the desertion of crops and field as well as to a decrease in stock breeding practices. All this meant an instantaneous take over of shrublands and forests which have been used by wild boars as diurnal shelters.