Coyotes don't seem to be much threat to deer, at least here. We have an abundance of both. Just a few weeks ago I watched a coyote that seemed to be trying to catch a deer in a 50 acre corn field...the corn was up perhaps 2' so I couldn't always see the coyote. The coyote would head for the deer (a yearling I'm guessing....perhaps 80#) at a fast trot, and when it got within 20-30 yards the deer would jump and run maybe 50-100 yards. I watched this scene repeat probably 7-8 times before the deer finally turned and disappeared into the woods. It was almost laughable. Perhaps the result would have been different with more coyotes, but I think most of our mature deer (120 and up for most does, 50 more for bucks) would kick the snot out of a coyote or two. I really don't know what the average is, but I have seen many 200# + bucks taken around here over the years. I took one 15 years ago that was 230 field dressed; I would think they could do some serious damage.