Owls

How owls swivel their heads

It's the owl's greatest trick - turning its head almost a full circle.

     The puzzle has been how the bird doesn't throttle itself in  the process. If we did it, we'd cut the blood supply to our brains and  pass out.

"They haven't developed just one answer to the problem; they have several answers," said Dr Philippe Gailloud from Johns Hopkins University School of Medicine.

     "And it's because of this set of solutions that we don't see  lots of owls lying on the forest floor having suffered strokes," the  interventional neuroradiologist told BBC News.

http://www.bbc.co.uk/news/science-environment-21279609