Night barking requires management

My Pyr is wonderful in almost every way but the barking is a real consideration. He patrols at night and barks at things that I cannot identify. We live in a rural area so the neighbours are distant but in a suburban setting this would be a serious problem. He is an independent thinker who does not take orders so much as consider them. With a flock to guard he is purposeful and brilliant. As a pure pet he needs a patient owner.