Jack Sparrow Asleep

So I caught Jack napping.  I was amazed when he didn't move quickly to the wall of his cage when I came near.  I suddenly realized that he was sleeping!
All that was visible was the white panel on the side of his head, no beak.  It seemed like he was tucking his head under his wing (da poor ting) as in the song, but this article I read says that he was actually resting his head on his back feathers to relieve the stress on his neck.  Here's a link telling about avian slumber:http://www.birdwatchersgeneralstore.com/snooze.htm