I'm kind of with Rack.
A mature buck is harder to kill than a mature doe, based on personality. The buck will go nocturnal, and only has to worry about his survival. The doe has young that she needs to take to food and tend to. That's not saying the doe isn't wary or a worthy adversary, just that she has to take way more chances. Young bucks and does are fairly easy to kill. Young bucks cause they are really dumb, young does cause there are lots of them.