When calves get a little older you may find at mid-day, out on the prairie, some mile or two from water, a bunch of maybe forty calves.

Their mammies have gone to drink; but not all of them! No, never all of them at the same time.

One cow is always left to guard the helpless calves, and carries out her trust faithfully until relieved.

This was and is still a complete mystery to me.

Does this individual cow select and appoint herself to the office; or is she balloted for, or how otherwise is the selection made?
This might be another picture subject--the gallant cow on the defensive, even threatening and aggressive, and the many small helpless calves gathering hastily around her for protection.