The thing we never know in most of these videos is what leads up to the takedown. The videos leave no doubt that coyotes will attack and kill an adult deer. But are these healthy adult deer? A number of the videos are in snow and ice. Is the deer sick or starving? In the ones with bucks, they have horns. Is it deer season? Have they been hit with an arrow or a bullet? In SC many deer are wounded by cars.
Anyway, the evidence surely points to coyotes attacking and killing adult deer and the doe I saw being chased was clearly very healthy. So it seems reasonable to assume that coyotes will chase, and possible catch and kill adult deer. Others have cited pretty heavy fawn tolls by coyotes in some regions. So the question is, will deer predation by an ever increasing coyote population have a significant effect on deer herd size. Obviously this will vary by region, climate, coyote populations and deer populations. But there can be no doubt that coyote populations are growing fast here in the SC piedmont. There are times when we can hear literally dozens of coyotes in a 360 degree arc around out cabin. During calving season you see them all the time, day and night. And the DNR is encouraging pretty much indiscriminate killing of coyotes. (A hunting license is required, but there is no season and they can be hunted at night. A trapping license is required and there is a season for trapping.)
Finally, the question I have to ask myself is do I want to actively hunt and kill coyotes, and or kill them whenever an opportunity arrives. I would say yes, but with the realization that in reality I will have no significant effect on coyote populations or the effect they have on cows, deer, turkeys or foxes. But, it is legal, I enjoy it and it makes me feel better about at least attempting to restore a balance to the property I own and manage. What the right 'balance' is is open to much debate but I have an idea how I want things to be in my neck of the woods and that is what I will strive for.....that is what management is all about, right?
P.S.: Years ago I read an article that coyotes where also integral in decreasing quail populations even thought they do not actually kill and eat that many quail. The thinking was that coyotes kill foxes and foxes are much more effective predators of rodents than coyotes. Then rodent populations increase and rodents prey on quail nests. I make no claims as to the validity of this idea. Quail populations around me seem to be stable or maybe slightly on the rise. I have also read that feral cats and roaming domestic cats take a major toll on quail and song bird populations......I'd be willing to bet that coyotes take a healthy toll on roaming cats...which is a good thing.