With caribou, it's either feast or famen! Nothing wrong with "feasting" when the opportunity comes!!
From what my AK friends have told me and what I have seen on hikes in the tundra this is entirely correct! I have crept up to caribou within in 10 yards and they just sit there. I have also had them spook 400-600 yards out! They are a different critter than our average whitetails, mulies, and elk that have a lot more people to deal with!