I keep thinking a big jag could live pretty well off hogs, if they ever get established in Texas, and start breeding. Last I heard, though, it was only the occasional roaming male that ever made it into the States.
In the deep jungle, a black jag would still be well camo'd, and he'd have no disadvantage in stalking prey. In the desert or semi-desert I would have to think a black cat would be at a disadvantage, and natural selection would limit their numbers. Mutations do happen, heck white buffalo show up every now and then, but I can see why it would be extremely rare.
