Surprisingly, the animals aren't just living in nature reserves or remote wilderness, but appear to co-exist in areas dominated by humans across a third of Europe's land mass, the authors wrote in their article published in the journal Science on Thursday. Guillaume Chapron, a researcher at the Swedish University of Agricultural Sciences and lead author of the study, cited the example of local herders in northwestern Spain who tolerate wolves killing mountain ponies because that keeps them from preying on more valuable cattle.