There are several species of deer that are hunted each year. Whitetail deer are by far the most hunted deer species, making up roughly 82% of the total deer hunting in the United States. Mule deer, Blacktail, Couse whitetail, Sitka blacktail, and Columbian whitetail make up the remaining deer species hunters pursue each fall. All of these deer live in vastly different habitats and have different habits, but one thing is true of all deer- they are extremely wary, and getting close for any length of time is very difficult.
The whitetail is arguably the wariest species probably because they are the most intensely hunted. With whitetail one of the things hunters see often is when a big buck is heading their way, the deer will oftentimes just look up in the hunter’s tree stand for no apparent reason. The wind can be right and the hunter can be silent and motionless yet the deer seemingly just knows the hunter is there. For years this was a mystery but it’s a problem that has plagued hunters for centuries. Once the deer does this invariably the next reaction is either foot stomping and snorting (which also alerts all the deer in the area that something isn’t right) or the deer will turn and bolt away. We now know that in many cases the reason the deer is acting this way is that he senses the presence of another large living being in close proximity by the bioelectric energy that we are emitting. His instincts kick in at that point and it gets really hard for the hunter from that point forward.
Hunters see similar reactions from the other deer species as well. A great example of this is stalking mule deer (or even Blacktail and Coues deer for that matter). Bowhunters know that getting into the range of a bedded mule deer is the ultimate challenge. Once a hunter gets inside about 50 yards of a bedded buck experienced hunters know that the stalking becomes extremely difficult and it is usually not long before the deer senses your presents and comes up on the run.
This makes for very difficult archery shots! Bowhunting hall of fame member and arguably the most successful bowhunter of all time on giant mule deer, Randy Ulmer, once told me that when stalking mule deer he simply never tries to get inside of 40 yards of any mature bedded buck. The reason is “they will just know you are there if you try to push in to close even if every condition is in your favor.”
Again the culprit is the electrical emissions that our bodies naturally emit through heart rate and muscle movement. Adding to that is if the hunter is getting excited as the distance closes. You see the faster your heart rate the more bioelectric emission you have making the situation even worse. Once that buck (no matter what the sub-species) senses the change in his electrical environment he is hard-wired through eons of evolution to instinctually react and work to either put space between himself and that field or at the very least move to positively identify what is emitting the energy. Once this happens coming home with that buck is exceedingly difficult for the hunter. The fact is almost all experienced deer hunters have seen the results of biosignature recognition but it is only in the past 15 to 20 years that science has finally figured out the cause of this phenomenon.