Had it happen to me one time. My brother-in-law shot a doe a couple of years ago. He made a decent shot but it was a little back so he decided to give her a little extra time. It was a morning hunt and he waited a couple of hours before coming over to where I was sitting. We took up the trail and followed her for approx 200 yards when up ahead of me I saw a big pile of hair and the ground was all tore up like something had been fighting. Another 40 yards through the brush and there she was....well what was left of her anyway. As we were standing there in disbelief a coyote took off out of the brush 30 yards in front of us! It's amazing how fast they can devour a deer. It had only been 2 1/2 hours since he had shot the doe till we recovered her. Undoubtedly the coyotes had tracked her and got ahold of her before she was dead. That's what the area of hair and blood was 40 yards away!