Personally, I never hike nor hunt nor scout nor camp without a pistol on my belt. I usually use a .357, because of the balance of weight and capability of the cartridge. Perfect for where I live. 9mm is second string, but the closer I am to the border, the more it gets considered as a legitimate alternative to the .357 due to capacity.
The pistol goes with me regardless of whether I'm hunting with a shotgun, rifle, or .22 pistol - yes, sometimes I hunt small game with a .22 pistol. Even then, a serious pistol is still riding on my hip.
For just scouting, I almost always leave the heavier long guns at home. If I want to plink or possibly shoot a rabbit, I take along a .22 of some description. I have friends who routinely hike with an AR or .30-30 when not hunting for protection. I don't question their decision, but I don't follow suit. .357 or full-sized 9mm, depending on where I am, suffice for protection needs. I haven't gone stump shooting with a bow in far too long, though. Hmmm. Maybe next weekend, I'll have to think about doing some of that.