For centuries, people have looked to owls as symbols of wisdom, mythical guides and protectors, and sometimes even spooky harbingers of death. About 250 species of these captivating birds, with their penetrating stares and mysterious vibes, live on every continent except Antarctica. Here are a few fantastic facts about them, from their asymmetrical ears to their unexpected connection to a medieval poet.
Owls Can Turn Their Heads 270 Degrees
No, owls can’t turn their heads completely around (as a popular myth suggests), but they can swivel three-quarters of the way. They have a few anatomical adaptations that make it possible, such as extra neck vertebrae that allow their heads to turn and rotate at multiple angles. But until a few years ago, it wasn’t clear how owls could do these moves without also twisting their arteries and cutting off blood to their brains. In 2013, a team from Johns Hopkins University injected dye, representing blood flow, into several owls that had died of natural causes, and then manipulated the birds’ heads. The dye pooled into “reservoirs” under the animals’ jaws, which suggested that when owls pivot their heads, these reservoirs maintain a supply of blood for their brains.
Owls Can’t Move Their Eyes
An owl’s eyes are proportionally enormous, comprising up to 5% of the animal’s body weight (for comparison, human eyes make up about .0003% of our total weight). Their huge size — along with pupils that dilate extra widely and a reflective layer at the back of their eyes to utilize available light — are adaptations for zeroing in on the movements of tiny rodents and other prey at night. However, they can’t move their eyes much in their tubular sockets. Owls do, however, have binocular vision (the ability to merge information from two eyes into one image, like humans), which increases their depth perception and allows them to judge the distance to their prey accurately.
Lopsided Ears Give Owls Excellent Hearing
They’re usually not very noticeable, but owls do have ears, and they serve an important role in hunting. Their ears are often situated asymmetrically, with the right ear a little higher than the left in most species. Sounds made by their prey, like rodents scratching in leaf litter, will hit each ear at slightly different times, allowing the owl to triangulate the location of the sound. Most owls also have circular patterns of specialized feathers to channel sound into the ears.
These anatomical arrangements pay off: Experiments with barn owls have shown that their incredibly sensitive hearing helps them find prey in complete darkness; they will often hover over prey and listen to its movements before striking. Great gray owls have also been observed successfully striking prey hiding under a layer of snow.
Their Silent Flight Has Inspired Quieter Machines
Owls sport specialized feathers that muffle the sound of their wings flapping and let them sneak up on a meal. The feathers on the leading edges of their wings have comblike structures that dampen air turbulence and cut down on “whooshing” noise, while finer feathers on the top and trailing edges further break up the sound, resulting in a virtually silent flight. Engineers have tried to mimic this quality when designing quieter aircraft, wind turbines, drones, fan blades, and more.
Not All Owls Are Night Owls
Most of the world’s owl species are nocturnal — they’re more active at night, with physical adaptations for hunting by moonlight. In North America, these denizens of the dark include the adorable, football-shaped northern saw-whet owl and the diminutive eastern and western screech owls. Some species can be seen hunting at dawn or dusk as well as at night; barred owls, great horned owls, and long-eared owls are considered crepuscular (most active at twilight). Diurnal species are primarily active during the daytime: Short-eared owls and snowy owls can often be seen flying over grasslands in search of rodents, while northern pygmy owls and northern hawk owls live in forests and are seldom spotted.
A Group of Owls Is Called a “Parliament”
This collective noun has an unusual literary source. In The Silver Chair, one of the books in C.S. Lewis’ Chronicles of Narnia, a talking owl named Glimfeather calls for his fellow owls to form a parliament; the group of birds advises the novel’s two protagonists on their quest. Lewis was actually riffing on a literary antecedent, Geoffrey Chaucer’s 14th-century poem A Parliament of Fowls, in which the narrator dreams that Nature gathers birds together to choose their mates. Thanks to the worldwide popularity of Lewis’ Narnia books, people began using the word “parliament” to define a group of owls by 1968, according to the Oxford English Dictionary.