Wild boar Sus scrofa mortality by hunting and wolf Canis lupus predation: an example in northern Spain

Abstract

Over the last decades, wolf Canis lupus predation in northern Spain has focused on wild ungulates, even though livestock and other prey, such as other carnivores and small mammals, and garbage have been available. During 1994 and 1995, we studied the impact of wolf predation on wild boar Sus scrofa in four study areas in Asturias, Spain. The diet of the wolf was assessed by scat collection and analysis (N = 106, 329, 372 and 649, respectively). The mortality of wild boar was deduced from density estimates and hunting records from the Nature Reserve of Somiedo. Wild boar represented 3-31% of the biomass of food found in the wolf scats in the study areas. We estimated that 75% of wild boars eaten were piglets. The wild boar mortality rate was estimated at 38% (146 dead individuals out of 385). Wolf predation was estimated to cause 12% of the mortality of wild boar and to affect 4.5% of the wild boar population. Hunting had a higher importance as a mortality factor than wolf predation (31 and 12%, respectively). Even though, a two-year study is insufficient to come to a final conclusion, our results suggest that wolf predation may have a low impact on young wild boar and that a hunting pressure of the size we found is unlikely to control the wild boar population.