If you’ve ever seen an owl spin its head backwards or upside down, you’ve probably wondered how on earth they do that. Burrowing owls are one species that can perform this alarming feat with their own particular brand of charm.
How burrowing owls spin their heads:
Owls like the burrowing owl have the uncanny ability to spin their heads up to 270 degrees, almost a full circle. But how do they do this, and why? First, scientists injected a harmless dye into the arteries of a group of owls. Researchers wanted to know why blood vessels aren’t restricted or severed when the owl turns its head to these extreme degrees. They could then follow the blood flow through CT scans.
They also examined deceased specimens and found that the neck bones of owls have large holes, much bigger that those of other birds. These holes can hold air that act as a cushion as the owl moves its head into these inverted and backwards positions. They also found that there is additional slack in the blood vessels in their necks, which is why they don’t stretch or break. Add to that a second pivot point in their necks (unlike the singular point humans have) and they can move their heads with an incredible range of motion.
The “why” of these cranial acrobatics is tied to the owl’s eyes. As with most owls, the burrowing owl’s eyes are somewhat stationary. They can’t flick their eyes from side to side so, to compensate for this lack of peripheral vision, they can turn their head enough to look backwards. Their eyes are tubular rather than spherical and, while this gives them excellent eyesight, it limits their mobility.
Take a look at this video of a burrowing owl showing just how far he can turn his head, and how that rigid stare can be quite enchanting as he gazes curiously at this photographer.
Video by youtube/Heykayde
Photo from Kimberly Collingwood/Unsplash
