I've got a friend that hunts coyotes all winter. He regularly finds carcasses and lots of tracks. There's no way to tell what the deer died from, but judging by the number of carcasses he finds thoughout the winter it doesn't look like natural causes...unless you consider coyote kills natural. Coyotes are very efficient predators, so it wouldn't surprise me to find them bringing a bunch of fawns back to the den....easy pickin's if you ask me.