There are so many factors that need considering when talking about the life span of deer. Many of these factors are specific to your region. Wolves and winter in Canada for instance. Lions and EHD here in Wyoming. Now lets consider vehicle, farming(fawns), pollution/loss of habitat. This really is a HUGE question that when we think about it, shows us how damn tough and adaptable the rascals really are. Five years in a whitetails life is 43800 hours of looking over your shoulder.....somebody's trying to stick you, hit you with there truck or bury there teeth and claws in you. Amazing!