Dept biologists said coyotes had zero impact on deer numbers...they didn't KILL deer. They were as wrong about that as they were killing does.
The dept biologists (many of them) have said the same thing I've always said. Coyotes do kill SOME deer, but certainly nowhere near the amount we're lead to believe.and killing does can be very beneficial to the overall health and age structure when the local deer numbers are taken into account. Obviously it doesn't apply everywhere to every piece of property.
Coyotes are likely taking out any weak, wounded, sick deer in the population. I've seen enough now through tracking that I'm certain they target the wounded deer hunters shoot that are marginally hit. It took me a while to put two and two together and but now that I know what I'm looking for......I see a lot of evidence of coyotes getting to the wounded deer before us and taking it on out. They aren't doing it by just jumping on it and attacking it when they find it. They get it up and push it just like we do when I'm tracking if we jump a wounded one. They just follow along behind trailing it until the injury or ailment wears them down to the point of exhaustion. I see it commonly on leg hits for instance. The buck can run fine to start with....but then after awhile that one good front leg starts wearing out of him and suddenly he can't climb that ridge or cross that steep creek bank. I've watched my dogs track one partially up a ridge and back down....up it again...and back down....before finally just staying in the bottom. Once the deer reaches the point of exhaustion then that's when the coyotes....most likely in packs....take it on out. Probably without to much of a fight at that point.
I've even seen though where they attacked some straight out of the bed. The evidence was big wads of white hair leading in a bread crumb like trail away from where the deer had initially bedded. I also commonly find deer that should have never went as far as what they did on their own and they'll be eaten up by coyotes once we do find them. I've seen them have green gut matter blown out at the hit site the size of a paper plate and when we get to where they bedded at 300-400 yards, no deer to be found....where did we find it??...Over a mile away with nothing left but a skeleton and rack. One of the last deer I tracked this year was shot in the hind quarter and up into the back of the guts with a 7 mag. It ran to a prime spot for one to bed up...wet and thick along a small creek. He left from there though and continued down the little creek for 1100 yards....moving through prime bedding cover the entire way. He didn't go that far on his own will....the coyotes got him up and pushed him....he was eaten up too. I can give you one account after another of situations where I'm just about positive its happening. Wounded deer don't want to go any farther than they have to. I'm sure there's some exceptions but you're just not likely to see one travel these long distance without being pushed.
I wonder if this is the same thing the red wolf did as well. It would only make sense that a predator like this would choose the less risky method of taking a deer out. I'm not sure how big they are but it would hard for me to believe that they attacked and took down full grown deer with any regularity. I would think they likely targeted the weak and injured as well. If so that means that the coyote is replacing them and the population could be controlled by them. Just a thought anyways