I am of the opionion that wolver is plural as in wolver > wolv = Wolfs > wolf.
Example, "See them wolver, that one is an ash tail, and that large wolv is an alpha, be carefull!"
I would love to hear peoples opinion making cases for either way, also +1 for making a case based on in game lore!
A quick search of the forums shows 6 threads that mention "wolv", one if which is this one, while there are 81 pages of threads that mention "wolvers". So, uh, no. "wolv" is not the singular and the plural is "wolvers".