As Jack_Flash stated, a similar thing was happening in the pasture behind my house except there weren't any calves, just steers. I would shine my spotlight out and they would have the steers herded into a circle. I can't imagine that 'yote could kill a full grown steer but what else could they be trying to do. I started off just throwing out a firecracker to scare them off. After about three times of being waken in the middle of the night from their yelping I'd had enough. I took this one from a little over 100yds with my .223. I've only seen 1 since so apparently they got the message.
