Why Are Owls
DT-XVII: How and why can owls turn their heads 270 degrees like victims of demonic possession?
Fun fact: my roommate loves owls. When we first moved into our apartment three years ago he brought with him two owl figurines and an owl mantle. Plus an owl portrait. Since then he’s added an additional owl sign.
As animals go, they’re not the worst ones to be obsessed with. Big, innocent (or spooky) eyes, rotund bodies, swiveling heads, and a strangely inquisitive onomatopoeia. Pop culture is full of owls: Hedwig, Archimedes, Wan Shi Tong, the opening credits of Labyrinth…
My curiosity drove me to google where National Geographic told me that owls can turn their heads because, unlike humans, their heads are only connected by one socket pivot instead of two. They also have twice as many neck vertebrae as we do (14 to our seven).
Still, it raises further questions. Scientists have been puzzled for a while as to how Owls can do this without dying. As this article puts it:
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.
—John Hopkins University of Medicine
Thanks to a lot of dissection and imaging from the white coats at John Hopkins, we know that owl arteries work quite a bit differently than our own.
Unlike humans, whose blood vessels get smaller and smaller as they move from the heart, owls get larger and can even balloon while their heads are turned. This way blood can pool in reservoirs.
Additionally, important arteries pass through bony holes in the vertebrae that are ten times larger than the artery, creating an air cushion that protects the arteries from tearing.
But the crowning jewel are the various circulatory system detours. In most human beings, our blood can only reach our brain through a single predefined path that we’ve developed over millions of years of evolution. This is why the smallest interruption of that path (by the sudden jerk of a chiropractor for example) can disrupt our whole shit.
Not so with our good friend the owl. Owls have detours and side paths built into their heads, where arteries can exchange blood with each other so that when one path is blocked (by a head being turned) the blood has another path to the brain.
But if you’re anything like me, understanding the how really isn’t enough—it’s all about that why. And for owls the why goes all the way back to their function as nighttime predators.
As this video explains, owls can see really, really well in the dark, but their eyes can’t swivel or rotate within their sockets like ours can. So instead, their entire head needs to swivel and rotate 270 degrees in either direction. Visualize the owl as a lighthouse.
Now for my final question.
Who?