Johns Hopkins Experts Study How Owls Are Able To Contort Their Heads And Not Lose Blood Supply To Brain

Although not an entire 360 degree rotation, owls can spin their heads 270 degrees around. The most limber of humans can turn their head 180 to glance over a shoulder. Still it has baffled onlookers as to how these contortionist birds of prey manage to twist and tilt their heads in such an extreme manner, without causing injury to themselves.

Scientists at Johns Hopkins University School of Medicine studied over a dozen snowy, barred, and great horned owls, and have determined there are four major adaptations which facilitate in the bizarrely flexible head movement. Necropsies (performed after a natural death), angiography, and CT scans were used to discover the unusual biological characteristic.

The study’s senior investigator, interventional neuroradiologist Philippe Gailloud M.D., is an associate professor in the Russell H. Morgan Department of Radiology at the Johns Hopkins University School of Medicine.

“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.”

The birds have a distinctive bone structure and vascular system. These unique functional alterations prevent the loss of blood supply and injury. Humans do not have this attribute, therefore we are more prone to injury if we try to hyperextend our necks.

There are nearly 205 species of owls, sorted into two groups: barn owls and true owls. The distinctive difference between the two types is barn owls have heart-shaped faces, whereas true owls have rounder facial structures.

The feathering of all types of owls range from muted, mottled shades of brown, gray, and white. This allows for concealment from predators, and gives an owl the upper hand when sneaking up on prey. Owls are primarily nocturnal, avoiding conflict with hawks and eagles. Although there are a few species that are out in the daytime.

Owls hunt for small animals such as squirrels, mice, and other birds, insects, and reptiles. They have keen binocular vision, but their eyes are fixed. Therefore, owls must turn and twist their heads to see in every direction. They’ve evolved the ability of silent or near silent flight.

Culturally, owls are indicatively wise and noble, as demonstrated in children’s stories and movies.

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