Years ago my grandfather was a government trapper. We got called to a ranch loosing sheep. By the way they were killed it was dogs. There wasn't any running loose for miles. So the traps and snares went out. Ended up catching a set of really good border collies, trained sheep dogs and good ones. Theses dogs ran loose, wouldn't bother the owners sheep at all. They chose to travel about 5 miles, through several ranches with sheep and goats. Guess the dogs felt they were far enough no one would know, they were some sheep killing dudes too.
Them dogs were trained to do that knock the competion out then the market was good for the man who had them!