Noisy Night Bird.

This bird was making a repetitive whistling sound into the night. It started again at 3am. Loud for a bird this size. A little bigger than a magpie lark. Dont know what it is. It was in a dense tree so not a good shot. I would say that he was in the same spot for 12 hours at least. Any ideas?

untitled-4647.jpg by robert, on Flickr