IMO, a good 9MM would do a bang up job. There's some seriously powerful ammo out there. Plus, there's always the capacity advantage. It all depends, however, upon the dependability of your gun. I have a Star 30MI that has never jammed on me since I've had it (thousands of rounds.) I'd feel pretty confident with it.
A .38 SPL my be a bit soft, I think, for my tastes. Don't get me wrong, I love .38 SPL. I reload it and my bedside gun, which is also my favorite shooter, is a Model 10. It's just that snarling large wild animals seem to be high on the muscle and adrenalin scale, compared to humans. Thus I'd want the extra ft lbs of the 9MM. During a mauling, 17+1 sounds pretty appealing.
Some of the hotter .45 loads would do well, too, I guess. An M1917 would be a good choice. A semi-auto, if very jamless, would even be better.
I have no experience with a .40 so I'll remain mum about it.