Adaptive Diet Strategy of the Wolf (Canis lupus L.) in Europe: a Review

The diet strategy of the wolf in Europe is reviewed on the basis of 74 basic and 14 additional literature sources. The comparative analysis reveals clear dependence on the latitude (and, therefore, on the changing environmental conditions) correlated with the wild ungulate abundance and diversity. Following a geographic pattern, the wolf is specialised on different species of ungulates: moose and reindeer in Scandinavia, red deer in Central and Eastern Europe and wild boar in Southern Europe. Where this large prey is taken, the roe deer is hunted with almost the same frequency in every region. The wolf diet in Europe shows two ecological adaptations formed by a complex of variables: 1. Wolves living in natural habitats with abundance of wild ungulates feed mainly on wild prey. 2. In highly anthropogenic habitats, with low abundance of wild prey, wolves feed on livestock (where husbandry of domestic animals is available) and take also a lot of plant food, smaller prey (hares and rodents) and garbage food. The frequency of occurrence of wild ungulates in the diet of wolves in North Europe varies from 54.0% in Belarus to 132.7% in Poland, while that of livestock is in the range from 0.4% in Norway to 74.9% in Belarus. In South Europe, the frequency of occurrence of wild prey varies from 0% in Italy and Spain to 136.0% in Italy, while of domestic ungulates ranges between 0% and 100% in Spain. The low density or lack of wild prey triggers the switch of the wolf diet to livestock, plant food (32.2-85% in Italy) or even garbage (up to 41.5% in Italy).