Wolves may catch a few beaver, but when it is froze up I can guarantee you that they can't open a lodge and get to them. Wolves are somewhat leery of a large beaver because they are a dangerous. A beaver to protect himself immediately go for the legs and can beak them with ease.
I have an aquiantance in Orr, Minn. and the wolves put him out of the cattle business. In the winter the wolves on a couple of occasions chewed through a closed barn door and killed cattle. This was documented by the DNR and they paid for depredation losses. In the spring,calf depredation was very high. The pack got established in he area and devastated it. This was before they were delisted. Because of depredation, over a 9 year period the Feds killed 61 wolves on his property, and they finally bought his cattle business out. Wolves, in late winter and early spring when they kill a cow, deer or what ever just eat the fetus and go on to kill something else. They only eat frozen animals if they are driven to it by hunger. If live game can be had they kill it.
Wolves are OK and have a place in the eco-system that contains lots of wilderness. But I don't believe they are compatible in populated areas where there is domestic livestock. All they have to contribute is the price of a hunting license. I also don't believe that they have the same genetics as the wolves did say century ago. They have become a cross bred, hybrid animal. The alpha instinct, and environment, food supply awareness in thier breeding traits of natural selection is gone. The Apostle Islands on Lake Superior is an example. The moose population crashed, the wolf population continued to grow due perhaps to inbreeding, now they have crashed to less than a half a dozen animals and the moose are flourishing again.
The wolf can no longer maintain a balance, which makes it necessary for us to step in and manage them.