My worry is how he'll handle the boredom that we all go through when nothing is moving as he gets older.
Boredom is not always good. Really not good to force young ones to sit still while bored (not just hunting). If I need my son to sit still with me for a period of time, I'll bring his gameboy and let him play for a few minutes at a time.
The way I look at that is that ifsomeone gets so bored still hunting when nothing is moving that they start to loose interest, there is always a choice that can be made to try and go find something, even if it is not the same game animal.
Personally, I was never able to sit for long periods of time when I was young. Now I can do about 4 hours max. I have done the all day thing in the past, but it's just not fun to me.