I would agree, this is a good question.

Besides natural predators, keep in mind that deer like any other animal on this god given planet, do not like being disturbed or bothered.

And like many animals including us, we have become aware of warning signs that alarm us. And in the woods this can be mistaken the deer not liking these particular animals.

For instance. I have been stalking or watching deer that have squirrels around them and when another squirrels is alamrmed by be or somthing ells, they sound the alarm inturn the deer notices this and also takes action to vanish.

The same with blasted crows! many times I have watched deer run out of view when they start, cawing!

I have seen coons, squirrlls, and other smaller animals pester deer and even challenge them to food! frusterated the deer have just walk off into the woods or go to another spot.

As far as fox I've seen them around deer and not alarm them. I've accually seem deer chase them as if they were playing games?

KEEP HUNTING THE GREAT OUTDOORS & GOD ALIVE, PASS IT ON!