![]() ![]() Although there are many exceptions to this rule, a 2018 study found that, overall, nocturnal owls are more likely to have dark eyes (like the Barred Owl), while owls active in daytime or at dusk are more likely to have orange or yellow eyes (like the Snowy Owl). In fact, some owl species are more active during the day than at night - and eye color can be a good indicator as to which type of owl you're seeing. They can dilate and contract the pupil of each eye independently, giving them an amazing amount of control over just how much light hits the retina in each eye. Not true! Owl pupils can contract in bright light just like ours do. ![]() ![]() There is a common misconception that because owls have excellent night vision, that means they're blind in daylight. Of course, even owls can't see in total darkness, but some species, such as Barn Owls, can hunt by sound alone, able to catch mice even in a sealed, pitch-black environment. Owl eyes are so big that in some species, you can actually see the base of their eyes by peeking into their ears (check out this article from 2018 for some amazing photos). They can't literally turn their heads all the way around, but they can rotate them 270 degrees (three quarters of a full circle) in either direction, plus 90 degrees up and down. To compensate, owls have evolved their famous ability to turn their necks incredibly far in either direction. These rigid rings prevent owls from being able to move their eyes - you can roll your eyes to the left or right while holding your head still, but an owl's eyes are fixed in place, pointing straight ahead. Owls have special bony structures called sclerotic rings to support these huge eye structures and hold them in place. They're more elongated than human eyes - yet another special adaptation to help them work more efficiently in low light. Owls' eyeballs aren't really balls at all. There's just one problem: fitting those gigantic eyes into the relatively small skull of a bird. The one downside is that owls tend to be farsighted and experience difficulty focusing on objects at close range, but sensitive bristles around their beaks make up for this a bit, giving them another way to sense objects close to their faces. All of these adaptations add up: Some owl eyes may be as much as 100 times more sensitive in low light than ours. If you've ever been out at night and seen owl eyes shining back from your flashlight beam, you no doubt noticed their reflective power, which is yet another way that owls enhance their night vision.īehind an owl eye's rod-packed retina is another layer called the tapetum lucidum, which catches any light that may have passed through the retina and bounces it back to those sensitive rods. Humans have about 20 rods for every cone, but in owls that ratio is more like 30 to one, making them exceptionally good at picking up movement even when it's dark. Like us, owls have two different types of light-sensitive cells in their retinas - rods (which detect light and movement) and cones (which distinguish color). ![]() In addition to their out-sized eyes, owl pupils dilate extremely wide to let as much light as possible hit the light-sensitive retina at the back of the eye. These translucent “third eyelids” close horizontally from the inside corner of owl eyes and are there to protect them from debris when the owl swoops in for the attack.īarn Owl. This arrangement sacrifices depth perception for a wider field of view that gives them a better chance of spotting incoming danger.Īlthough humans and owls share binocular vision, owls are equipped with an important feature that we lack: nictitating membranes. Prey animals, on the other hand, tend to have eyes situated on the sides of their heads. In fact, owls have the most forward-facing eyes of any group of birds! This provides them with acute depth perception that allows them to gauge distance to perfectly time their attacks. Where their two eyes' fields of view overlap, owls have 3-D or “binocular” vision, a trait they share with humans and the many other predatory animals. This arrangement is actually an adaptation for tracking the movements of potential prey. Owls' distinctive “wise” appearance comes from the intense stare resulting from the position of their piercing eyes, both of which are located facing forward on the front of the head, like our own. ![]()
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