Thanks Steve and Mary for the lovely comments.

I was reading in my new bird book these birds dont build nests they lay their egg in another birds nest, than either the bird that owns the nest leave their nest all together or hatch the cowbirds egg, which is hatched earlier than their own bird.Well its very interesting.

This is quite a handsome bird in an understated kind of way! I like the blue irridescence in the black feathers.