Whitetails and mulies use different escape strategies and inhabit the type of terrain which best suits their instincts. Whitetails are hiders and will choose the most dense cover. Mulies rely on their eyesight to detect danger at a distance and then move away from it, often using their stotting gait to gain an uphill advantage on the predator. Unfortunately this is what makes the mulie more vulnerable to hunting because separation space from an animal predator will still leave them vulnerable to a rifle shot.
I'm fortunate to be able to "hunt" deer in one form or another on a daily basis. In the growing season I do wildlife damage claims on forage crops and spend a lot of time in the field observing the activities of bear, elk, sheep, mulies and whitetail (and getting paid for it

). When I visit a ranch I can pretty much predict whether it will be used by mulies or whitetails based on the terrain and type of cover available. River valley bottoms tend to be whitetail country, while hilly terrain is for the mulies. In some cases you will see both on the same ground. This used to be the case in the Battle River country around Wainwright/Hardisty, AB where we would often take both species on the same ground on the same day. I see this to some extent along the Similkameen River and Bridesville areas in southern interior BC, but the whitetails still go for the low ground while the mulies will be on the hilly, broken slopes. Where I live is strictly mulie country where the deer hang out around the orchards and vinyards on mostly hilly terrain. Most days I do a 3 mile hike and see an average of 15-30 deer per day. You can generally predict where they will be based on the wind direction and intensity as well as their current feeding opportunities, incl my wife's flower garden

. Mulies also seem to tame down more than whitetails, if not heavily hunted. Mr. Whitetail will always be a lot more jumpy and ready to charge for the nearest cover when he sees you.
It's interesting to see mulies making a comeback in east central SK where I grew up and started hunting. They were our native deer and are all that you see in the old homesteader's hunting pictures. They were pretty much shot out by subsistence hunting in the 1920s/30s. At the same time the whitetails moved in to exploit the agriculture and cleared land and were a lot more successful at making a go of it, in spite of the continued hunting pressure. My father shot a big whitetail buck in the mid '30s which was quite a novelty for all of the old timers to see. Nowadays the hunting pressure is a lot less and there are a lot fewer people living in the country, so the mulies are back and are co-existing nicely with the whitetails.
Like I said in my original post, deer are a lot more alarmed by human odor than by the smell of gun oil, so it is important to use the wind to your advantage.
