Our Calves and the Egret Birds

One day while looking out our dining room window I watched a funny sight - 2 of our calves were aggravating 3 egret birds.  The birds were on the ground and the calves would "make a run at them".  Naturally, the birds flew then landed.  Time and again the calves did the same thing - 6 times.     Finally, I suppose the egrets had endured enough of the calves antics.  They landed close beside the head of a mother cow grazing.  The calves observed, waited a little, then went off to explore.  Seems as though the calves were not going to bother the bird that close to the cow.  The egrets seemed to be pretty smart figuring that one out.