Disturbing the peace

Our garden used to be peaceful with one Red Kite pair nesting in a group of trees behind the kitchen.  But for the last two years there has been a second Red Kite pair nesting about 250m away in a different group of trees.  I managed to locate the second nest a few days ago.  Both nests have female Red Kites sitting on eggs or maybe even chicks by now.  The two males are guarding their territories and searching for carrion.  Occasionally their paths cross, followed by an aggressive aerial display and much screaming :-(