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How to keep your head on a swivel

Home - by - February 2, 2013 - 19:00 America/New_York - 7 Comments

Johns Hopkins


Lack of such adaptations could explain why humans are more vulnerable to neck injury

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

In what may be the first use of angiography, CT scans and medical illustrations to examine the anatomy of a dozen of the big-eyed birds, the Johns Hopkins team, led by medical illustrator Fabian de Kok-Mercado, M.A., a recent graduate student in the Department of Art as Applied to Medicine, found four major biological adaptations designed to prevent injury from rotational head movements. The¬†variations are all to the strigid animals’ bone structure and vascular network needed to support its top-heavy head. The team’s findings are acknowledged in the Feb.1 issue of the journal Science, as first-place prize winners in the posters and graphics category of the National Science Foundation’s 2012 International Science & Engineering Visualization Challenge.

“Until now, brain imaging specialists like me who deal with human injuries caused by trauma to arteries in the head and neck have always been puzzled as to why rapid, twisting head movements did not leave thousands of owls lying dead on the forest floor from stroke,” says study senior investigator and interventional neuroradiologist Philippe Gailloud, M.D. “The carotid and vertebral arteries in the neck of most animals – including owls and humans – are very fragile and highly susceptible to even minor tears of the vessel lining,” adds Gailloud, an associate professor in the Russell H. Morgan Department of Radiology at the Johns Hopkins University School of Medicine.

Sudden gyrations of the head and neck in humans have been known to stretch and tear blood vessel linings, producing clots that can break off and cause a deadly embolism or stroke. Researchers say these injuries are commonplace, often resulting from whiplashing car accidents, but also after jarring roller coaster rides and chiropractic manipulations gone awry.

Fabian de Kok-Mercado holds a barred owl.

To solve the puzzle, the Johns Hopkins team studied the bone structure and complex vasculature in the heads and necks of snowy, barred and great horned owls after their deaths from natural causes. An injectible contrast dye was used to enhance X-ray imaging of the birds’ blood vessels, which were then meticulously dissected, drawn and scanned to allow detailed analysis.


Adaptations of the Owl’s cervical and cephalic arteries in relation to extreme neck rotation


  1. Claudia

    February 2nd, 2013

    Cool. I’ll now stop trying to swivel my head…

    Thumb up +1

  2. Chieftain

    February 2nd, 2013

    When we lived in NC, we had a pair of Barred Owls that kept watch on our Koi pond. One of ‘em snatched a nice 3 pound Koi one night and spent the next three days eating it up in a tree. Impressive birds that are afraid of nothing.

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  3. even steven

    February 2nd, 2013

    @Chieftan… I have a pair of great horned owls living in the woods surrounding my house. I hear them often but have only seen them a few times. That’s part of the reason I keep the cats inside!

    Thumb up +1

  4. bubba

    February 2nd, 2013

    bubba enjoyed reading that. thank you.

    Thumb up +3

  5. RosalindJ

    February 2nd, 2013

    I feel like an it takes an owl’s flexibility to keep up with the administration’s crap, thanks.

    I listened to the Limbaugh Weekend at work today. He has the perfect term for what we’re going through since we’re not owls: whipsawing.

    Thumb up +2

  6. 123321123321

    February 2nd, 2013

  7. quick and easy chicken recipes

    February 16th, 2013

    Great read. Good post!

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