Why can owls see well at night?

Answer 1

The night vision of owls is 100 times as keen as that of human beings, because their eyes are especially adapted for seeing in the dark. But most are almost color-blind and the pictures they receive are slightly blurred. This is because their eyes contain more rod-shaped receptor cells than cone-shaped ones.

Operating in bright light, cone cells sharpen details and react to color. Rod cells gather light and owls have 10 times as many of these as do human beings. Each cell contains "visual purple", a substance capable of transforming the slightest glimmer of light into a sight impression.

Owls have exceptionally large eyes and can control the amount of light entering by expanding or contracting the pupil. Each pupil can act independently of the other so that owls can see objects in the shadows and in bright light at the same time. Owls eyes are so large that they are supported by thin, bony, tubular structures called sclerotic rings. Because of this the eyes are almost immovable and nature has compensated for this by giving owls extremely flexible necks, which enable them to turn their heads through an arc of 270 degrees.

These birds have excellent binocular vision as their eyes are in the front of their heads. This gives them a tremendous advantage in swooping on small lively prey, because distance judgment depends on binocular vision. To add to their advantages at night, the owls have outstanding hearing, keener than that of any other carnivorous bird.

Answer 2

As most owls are active at night, their eyes must be very efficient at collecting and processing light. This starts with a large cornea (the transparent outer coating of the eye) and pupil (the opening at the centre of the eye). The pupil's size is controlled by the iris (the coloured membrane suspended between the cornea and lens). When the pupil is larger, more light passes through the lens and onto the large retina (light sensitive tissue on which the image is formed).
The retina of an owl's eye has an abundance of light-sensitive, rod-shaped cells appropriately called "rod" cells. Although these cells are very sensitive to light and movement, they do not react well to colour. Cells that do react to colour are called "cone" cells (shaped like a cone), and an Owl's eye possesses few of these, so most Owls see in limited colour or in monochrome.

Answer 3

The night vision of owls is 100 times as keen as that of human beings, because their eyes are especially adapted for seeing in the dark. But most are almost color-blind and the pictures they receive are slightly blurred. This is because their eyes contain more rod-shaped receptor cells than cone-shaped ones.

Operating in bright light, cone cells sharpen details and react to color. Rod cells gather light and owls have 10 times as many of these as do human beings. Each cell contains "visual purple", a substance capable of transforming the slightest glimmer of light into a sight impression.

Owls have exceptionally large eyes and can control the amount of light entering by expanding or contracting the pupil. Each pupil can act independently of the other so that owls can see objects in the shadows and in bright light at the same time. Owls eyes are so large that they are supported by thin, bony, tubular structures called sclerotic rings. Because of this the eyes are almost immovable and nature has compensated for this by giving owls extremely flexible necks, which enable them to turn their heads through an arc of 270 degrees.

These birds have excellent binocular vision as their eyes are in the front of their heads. This gives them a tremendous advantage in swooping on small lively prey, because distance judgment depends on binocular vision. To add to their advantages at night, the owls have outstanding hearing, keener than that of any other carnivorous bird.

But owls can also see well in the daytime. Although most species hunt by night, others are active at dusk or in full daylight.

Answer 4

Owls are nocturnal, have binocular vision and keen hearing. Also can almost turn their head completely around. Besides keen vision, they depend on echo location just like bats. Did you know that 90% of an owl's diet is voles(mice)? Owls like to roost in pine and cedar trees. After digestion is complete, the owl regurgitates a pellet containing all the feathers/fur/bones of what it has consumed. In our area, the biology teachers have students count how many voles are contained in a pellet. Usually it is at least 20. Owls are absolutely essential at keeping the wild rodent population under control. Most owls breed in Jan- Feb.
Since they are considered a bird of prey, it is a federal wildlife violation to kill one.

Answer 5

I used to be more of a night owl, but the older I get the less I am one. Have to get up too early to get to work. On Friday and Saturday nights I'm still a night owl.

Answer 6

They cant see well at night at all. They hear things and that's how they catch there prey by sound not sight. If a mouse was not moving the owl wouldnt know anything is there until it made a sound. Look it up, they hunt by sound at night.

Answer 7

Geez, people....all of you doing an *uncited* copy and paste of the same Wiki links and *none* of you get the whole answer correct, for *shame*.

--Yes, owls do have *VERY* large eyes in their heads, and way many more rods (low-light, low-detail sensing cells) in their retinas than cones (colored-light, high detail sensing cells), and their eyes have almost no side-to-side mobility courtesy of their extreme size in their heads (no room for muscle to *move* the eye much more than a tiny bit up and down), *and also* because unlike human or mammal eyes that are nearly *round* in a head, Owl eyes are *bell-shaped* and have a *very large* retinal area even for eyes so large...and yes, owls *do need* that double-jointed neck structure to compensate for the lack of side-to-side motion and peripheral vision....

--Yes, Owls also posess very large pupils that dilate almost to the point of making the irises (the colored *muscle* that controls the pupil) vanish from sight when seen head on, which lets in more light....but there is one more thing.

--Owls, like cats, have a *reticula* in each eye. This bit of tissue that lies between the lens of the eye and the retina acts as a one-way *light gathering mirror* that increases the total amount of light *in the eye* by 50-75% depending on the situation. This is why owls *and cats* get that shiny pupil thing going on in the dark because that is the light being reflected off the reticula inside their eyes. THIS is what all y'all copy and pasters, this is what you MISSED in your rush to plagiarize a "Best Answer" as quickly as possible....

Oh, and for Extra Credit....many species of mammals have a reticula or similar tissue in their eyes.....all but *primates*, because that light-gathering tissue tends to make frontal vision even more blurry than normal (if it doesn't also distort colors), and with primates (monkeys, apes and people) daytime high-resolution color vision is *top* priority.

--But, back to Owls. :) Not only do owls have superior night vision, but many of the larger species are among the few bird species to have *external ear* tissue as well. Why? Combine this with their disk-shaped faces, front facing ears and the fact that their ears are asymmetrical vertically, and what do you get?

One of the few bird species that not only has the night vision but also has hearing so acute that yes, owls can passively *echolocate* their prey as well, which is also why so many of the larger ones even, still prey on mice and voles, because they squeak, which makes them show up *really well* even in total darkness.....

Boo-yah! How you like me now?

Answer 8

simple there are two types of sight cells in the eyes one is the rod cells and the other are the cone cells one type operate in the light and are sensitive to light and the other ones are sensitive only to the dark and operate in the dark only the owls have more of the rod cells which operate only in the dark and contain rhodopsin which is a pigment sensitive to the darkhence they see better in the dark
the cone cells contain the pigment-- iodopsin sensitive to light

Answer 9

It's down to the size of their eyes and the fact that the nerve receptors within the eye are more acute than our own

Answer 10

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