Abstract
Assessing the externalities of nature conservation policies, conceived as unintended socio-economic and ecological effects, is essential for evaluating societal costs and improving conservation strategies. This is particularly relevant in the case of wolf conservation and its interaction with traditional pastoralism, an animal farming system that provides valuable ecosystem services but is rapidly declining across Europe. We used structured questionnaires with Spanish herders to evaluate the environmental and societal impacts of livestock-guarding dogs (LGDs) as a measure to prevent wolf attacks. On average, farms with 750 sheep employed five mastiffs and three sheepdogs, with LGD numbers increasing in wolf-abundant areas. The number of mastiffs rose proportionally with herd size (0.6 mastiffs per 100 sheep), whereas sheepdog numbers plateaued. The estimated annual cost per LGD was €364, with LGDs contributing approximately 7% of a farm’s carbon emissions. Sixty-one percent of herders reported minor societal conflicts involving LGDs, primarily dogs chasing pedestrians or cyclists, while 1% involved minor bites. The likelihood of societal conflict increased with the number of LGDs on a farm. Additionally, each LGD caused an estimated 0.71 wildlife fatalities per year, mostly involving small mammals such as rabbits, hares, and young ungulates. These findings highlight the need for urgent coexistence strategies to balance effective wolf conservation with the sustainability of traditional pastoralism. Without targeted intervention, the continued expansion of Spain’s wolf population may increase costs to herders and foster growing public opposition to wolf conservation efforts.