First, let me say that you must be cognizant of the laws in the jurisdiction where you hunt. Some states, or some state or federal lands, etc…, have laws or ordinances that prohibit concealed carry while hunting in the field. For the majority of the nation that is exempt from such stupidity, there is no reason not to carry your concealed handgun while hunting.
And you should.
I find that a good number of people who do carry a defensive concealed handgun, at least occasionally, do not do so while in the outdoors, especially if hunting. Such individuals might be more inclined to pack a pistol while hiking or the like, but while hunting they do not see the need. Afterall, if hunting during gun season of any sort, you are carrying a high-powered rifle or a shotgun. Why would you want to also carry a pistol? Why bother?
I remind the reader that violence can happen even in the wilds and wilderness. I have actually experienced several run-ins with hostile elements in certain places I have hunted. In all such circumstances I was holding a rifle in my hand while I spoke to the threatening entity, but I also wore a concealed pistol, hidden on my person, and I was glad that was so.
Why wear a concealed handgun when you are already carrying a rifle? Simple: anyone can see the rifle in your hands, but nobody will know about the pistol unless you are physically searched. Many hunters open carry a handgun: unless carrying a big bore revolver in brown bear country, don’t bother. Carry a concealed pistol.
Violence that occurs in the wilderness is unlikely to be someone at a distance taking pop shots at you that you can retaliate against with your hunting rifle. Rather, violence remains predominantly a close-range affair. The more likely scenario is this: a single, or several, “fellow hunters” approach with the usual small talk, and at the right opportunity put a muzzle on you and take your long gun. Now, your fate is in their hands. Of course, that concealed handgun, deployed at the right moment of opportunity, can dramatically change that fate.
Be weary of those who approach you in the wilderness, crime is not absent from the great outdoors just because the average crackhead has no use for anything outside of his urban abode. Be cautious when approached by strangers and wear your defensive handgun. Whether walking the inner city or roaming the wilds of the forest, the handgun remains the primary tool of civilian self-defense, no exceptions.
For those that would argue that the handgun is too uncomfortable while doing vigorous activity, I would suggest that you need to find the right holster. This past hunting season I wore my usual gun, in my usual AIWB holster, and I walked up and down mountain sides for three days straight. I did not even know the gun was there. Find the right rig that you can wear, always, and wear it, always.