The return of Tsar Amba

Its become an almost recurring theme that whenever I frequent wolf-related groups/boards/forums, it is almost guaranteed for someone to say that wolves have no natural predators except man. This simply isn't true. Granted (staying within North America at least), bears and cougars may pick off the odd wolf, but not enough for them to be considered a serious threat. Indeed, wolves seem quite good at dominating other non-human predators throughout their range. In the Russian Far East on the other hand....