BIRDS - Scientists explain how owl can rotate its head without cutting off blood

Medical illustrators and neurological imaging experts at Johns Hopkins have figured out how night-hunting owls can almost fully rotate their heads - by as much as 270 degrees in either direction - without damaging the delicate blood vessels in their necks and heads, and without cutting off blood supply to their brains.

http://phys.org/news/2013-01-scientists-owl-rotate-blood.htm