EU Sanitary Regulation on Livestock Disposal: Implications for the Diet of Wolves

Sanitary and environmental regulations may have indirect effects on the wildlife and ecosystem services beyond their regulatory scope. To illustrate such effects, this paper examines how EU sanitary measures, in conjunction with additional regulations and socio-economic changes, have caused wolf diet to shift in Galicia, northwestern Spain. Prior to the bovine spongiform encephalopathy (BSE) crisis in Europe in 2000, livestock carcasses used to be left on the field and were eaten by scavengers and carnivores. As a result of the BSE crisis, sanitary regulations regarding the disposal of livestock carcasses were introduced. These regulations affected the populations of avian scavengers. We hypothesize that wolf ecology has also been affected by the aforementioned regulations. We analysed wolf diet for the period 2003–2006 and compared the results with those of a previously published study (1974–1978). We found a shift in wolf feeding habits following the implementation of these EU regulations. A decrease in carrion consumption was registered, and wolves increased their feeding on the rising population of wild ungulates, especially on roe deer, and on wild pony. Future regulations should assess their potential indirect effects in the early stages of drafting to allow for the design of proper mitigation measures.