America pacified the natives 100 years ago, there really is little need for "defensive" weapons any more in the wilds of Montana (for example).
Weapons to defend against "critters" can be useful, although I believe it's proven that pepper spray is more effective against bears than a pistol firearm (which usually takes several shots to be remotely effective)*
If all these reasons were really that true Canada would have even more lax laws than the US regarding firearms(larger with significantly less people and far more wilderness)**. It doesn't, in fact they are stricter and gun ownership (especially handguns) is significantly lower, with a third of the gun ownership per capita (even though hunting is still very popular here, due to the amount of wildlife still around).
Also worth noting that Canada has far more dangerous mammals left than the US - 25,000 Grizzlies in Canada compared to around 1,500 in the Contiguous United States(excluding Alaska) for example.
You can get handgun licences for protection from wildlife in many provinces, but they really aren't common (usually for people working full time in the back country). Most people just carry pepper/bear spray, which itself is usually registered.
*
http://www.fieldandstream.com/artic...pper-spray-instead-guns-stop-charging-grizzly