I wish I could draw the circle of peripheral vision I've seen pertaining to large ungulates, but in general, it is far larger than what we see. Again, tagging on to Tatume, prey species are different to predators. Prey sees all-around, while predators generally see directly ahead.

Also from yesterday:

I and my son were still hunting {ErikD, "smygjakt" på svensk I think, not sure norsk...?} and for a time I was on a trail recently opened up by loggers.

I was wearing a orange fleece vest over a camo coat {German surplus, a great match for our area for turkey, etc, and I buy them by the boxful as they are cheap and we wear them for chores around the ranch}.

Anyway, I rounded a little bend very quietly and there jumped up a whitetail. It bolted for about 10 steps and stopped, turning around to see what spooked it. It was screened by pine boughs, so I moved around the branches and there it stood in a little opening, and there I stood in the open as well.

I had my rifle on the animal and was momentarily confused. I thought it was a doe, then realized it was a spike buck, but only had one spike. The other was broken off. It was only 20 to 25 yards away, very close, and an easy shot. I held for a long time on the animal, placing the crosshairs here and there, and then got tired and whispered "Bang, You're Dead". I did not want this buck so I brought the rifle down and then kept walking. The buck trotted off.

OK, now, clearly this rascal saw me. He looked right at me for quite some time and was as I say, not more than 25 yards away. Wind was against him, but he saw movement and ME clearly. How come he didn't bolt? Who knows. I've shot a number of spikes and does under similar conditions, but very few big bucks that way as if they jump they typically keep going into cover. Maybe the spikes are just stupid...