Wherever wolves become common, they start having an effect on the surrounding ecology. Animals that once had no effective prey, now start acting differently. Take elk/red deer, (Cervus elaphus), for example. It seems that when they can feed, unhindered, in open areas, they have lots of calves. Which is fine, up to a point. But when wolves come into the picture, they flee to forest edges where it's harder for wolves to catch them. Only trouble is, the graze isn't as rich in the forested areas. So they don't have as many calves. Maybe that will keep the wolf population from getting out of hand.
IN other wolf-related news, there is a move to reintroduce wolves to the Scottish Highlands , again in order to control elk/red deer. These mammals(the deer, at least), have apparently gotten overabundant, just as they did in Yellowstone, before wolves were reintroduced. I don't know what, if anything, reintroducing wolves to the Scottish Highlands might do. Wolves tend to avoid people if they can, under "natural" circumstances, but although today the Scottish Highlands don't have that many people, they do seem to have a lot of sheep. And, like farmers and ranchers here in the US, farmers in Scotland might get a tad upset by having wolves around. Still, it's an interesting proposal, seeing as how there haven't been any wolves, anywhere in Scotland for some 250 years. And anyway, most people in Scotland live in cities and would probably love to know that there are wolves" out there". It's going to be an interesting time for both wolves and people. . . .