In old news, over a month ago I read that a Muskox (Ovibos moschatus) had been seen in the the forests of northern Alberta, five hundred kilometers south of where it would normally be found. (I first learned of the sighting on Cryptomundo, which is a good place if you want to keep up on what's happening with Bigfoot, which you probably don't.)
The appearance of a Muskox in the boreal forest is perplexing given that the Muskox is is currently found only in the tundra, and is considered to be ecologically limited to that particular habitat. I speculate, though, that the Muskox's restriction to tundra habitats maybe be an artifact of thousands of years of hunting by humans. The tundra may simply have been the only part of the Muskox's natural range in which human population density was low enough that Muskoxen could avoid being completely wiped out. Now that the Muskox enjoys legal protection from hunting, it may be expanding southward into suitable areas. A good analog might be the Caribou (Rangifer tarandus), which inhabits both the tundra and the taiga, and in historic times was found as far south as Maine.