Scotland was effectively dewilded in 1603, when King James I (confusingly called James VI under the Scotch arithmetic system) united the crowns of England and Scotland. Matters were left there for a while, what with King James being otherwise occupied with far more important matters.
A hundred years or so later, the two countries were officially united (under English rule, obviously) and Scotch life continued in a more-or-less (probably rather less than more) civilized fashion until 1999 when the then Prime Minister (the communist Tony B. Liar) effectively threw them out and made them govern themselves. Informed scholars argue that the rewilding of the Scotch began with this folly.
If they wish to reintroduce wolves and bears, that is entirely their affair. However, Hadrian's Wall needs to be made wildlife-proof as nobody wants those critters (or their ferrets, weasels and drunks) on the southern side of the border.