Due to their exceptional night vision and hunting instincts, owls can navigate through the dead of night.
This means, it appears that owls “Need” darkness to see, essentially making them blind during the day.
But, that’s a myth as:
Most owl species can see in the day almost as good as they see at night.
Now, you may be curious:
‘Why would an owl bother hunting at night at all?
Also, how come owls can see at night when most raptors don’t?’
Answering all such questions require some understanding of owl eye anatomy.
Probably, the most scientific approach would be comparing owl eyes to a diurnal raptor, say eagles that can see well during the day but not at night.
However, I doubt if contrasting an owl’s eyesight with an eagle’s vision will be insightful because we don’t see this world through a raptor’s eyes.
Therefore, I have decided to convey owl vision through human eyes.
So, let’s ask again:
Do Owls Have Good Daytime Vision?
They most certainly do.
Now, owl eyes are about the size of human eyes, making them the biggest eyes for any animal of comparable body ratios.
For instance, a 1.7Kg Great Horned owl has eyes weighing approximately 2.7grams.
To put that in perspective, owl eyes make up about 3-5% while human eyes account for merely 0.02% of their total body weight.
Theoretically, owls should have at least the same visual capacity as humans do.
It starts from the iris (the colored portion of your eye) adjusting the size of its pupil to take in light.
The lens focuses this light onto the retina – a membrane with photoreceptor cells, that senses light and helps the brain create images (See figure 1)
Owls only see in black and white but they can see in the dimmest of lights.
That shows how owls can see well in light, it does not tell us how it compares to regular vision.
So if you compare the two eyes, you will realize that human eyes are spheroids while owl eyes are tubular in shape
In fact, owl eyes are fixed in bony tubular skull bones that hinder any eye movement.
Consequently, owls can only see ahead of them
This is precisely why humans can roll their eyes in disgust, but owls will only give you mean stares.
Not even kidding, anyways,
Tubular eyes mean that owls cannot see on their sides as humans do.
- Though humans can turn their heads from side to side at 180 degrees, owls can turn their heads to about 270 degrees. This comes from owls having:
- Extra vertebra in their necks to support their nape.
- A singular freely movable joint at the neck, instead of two like humans do.
- Porous neck bones to keep arteries intact.
- Since owl eyes are permanently facing forward, they have limited monocular vision. However, they have exceptional binocular vision which gives them greater depth perception within 70 degrees range (See figure 4).
This implies that owls cannot see on their sides, but they can visualize the size the distance of any object with precision.
Figure 4: Representing the extent of Owl’s visual range with limits on the side and advanced Binocular.
All this validates an owl’s long-range vision even in light.
However, most owls still prefer hunting in the dark.
So, you may still be pondering:
Why would an owl deliberately choose a night when it has the largest eyes that can see light?
Are Owls Blind In The Day?
Now, you must understand that even though owl eyes function like human eyes.
Owl and human eyes are not identical.
The two differ from each other in the following respects (See Figure 5 for clarity):
|Differentiating Feature||Human Eye||Owl Eye|
|Lens||Medium-sized and relatively thinner to allow moderate light intake and better adjusting in kinds of lighting.||Thicker and larger to allow maximum Light intake.|
|Shape||Spheres that allow eye-rolling within sockets.||Tubular Shape that hinders eye movement, but reduces eye weight without compromising vision.|
|Tapetum Lucidum||Absent||A mirror-like reflective membrane behind the retina to focus better even with minimal lighting.|
Figure 5: Representing the Key differences in Human and Owl Eyes
Now, all these differences in owl eyes enable them to collect more light even with low light conditions.
If that does not make sense, you can feel a bit how an owl feels with daylight.
Say you spend 2 hours in a dark area to the point your eyes adjust, and then, you clearly see everything in that room.
Suddenly, your sibling walks in and switches on the damn light.
Likely, it will burn the hell out of your eyes because you were not ready for so much light.
However, you are inherently a creature of the daylight.
Imagine how much would it hurt an owl to see in the daylight when it has eyes adjusted to night all the time.
Another thing to mention is Owl pupils cannot constrict as much as human eyes do.
So, even if an owl comes out in daylight, it must half-close its eyes using its eyelids – a habit that makes it appear sleepy during the day.
Perhaps, you need more logical reasons for an owl to hunt at night than mere sore eyes.
So, let’s ask a similar question:
Why Do Owls Only See At Night?
Because Night is far more convenient for most Owls than the dazzling sunlight.
The comfort comes from the following reasons:
1. Nocturnal Hunting Adaptations
While most animals will find it hard to locate things in the broad daylight, owls are prepared to be creepy in the darkest of nights.
That boils down to evolution handing them down with perfect night hunting equipment:
|Owl Feature||How It Works||Remarks|
|Crooked Ears||Owl ears are located on different heights and positions. Consequently, one ear listens a split second later than another.||This allows an owl to hear a mole tunneling 1 foot below thick ice.|
|Eyes||Large eyes with reflective membranes and rod cells, allow owls to sense minimal light.||Owls can clearly see both during the day and at night.|
|Silent Feathers||Owls have serrated thick feathers that don’t make noisy air strokes.||This allows owls to fly without being detected.|
|Crushing Talons||Owls have gripping strength and long fearsome talons.||This allows owls maximum success with single strikes.|
|Piercing Beak||Despite being small, owl beaks can rip apart flesh.||–|
|Filoplumes||Facial hair-like extensions that help with measuring close objects as owls cannot see objects close to them.||Helps them navigate through victims at night.|
2. Lack Of Competition
Daylight is bustling with animals causing several distractions.
Which means the night presents a time of no competition for most owls as,
- Most animals don’t make noise at night that may disturb an owl’s sense of hearing, and therefore, its precision at hunting.
- Prey animals are vulnerable at night, making them easier to grab and consume.
- Most predators that steal other animals’ prey are not present at night.
- Competitors like hawks and eagles don’t present territorial disputes in the dark.
3. Eye Protection
Again, daylight is too bright for the owls as they must use their eyelids to adjust light intake.
Therefore, activity at night is easier for owls.
That said, none of these reasons restrict owls from hunting or traveling during the day.
Do Owls Fly Around During The Day?
They do but only if there is actual need!
You see, owl feathers are serrated with minute feathers arranged above regular feathers.
While this reduces air turbulence and silences an owl’s flight, this makes their wings heavy.
It’s harsh for an owl to take long flights even at night, or ride thermals as other raptors do.
So, if an owl is flying around during the day, it may involve
- Potential Mates
- Threats and Territorial Claims
- Scouting the area to locate potential Prey
That said, some owl species regularly hunt during the day.
For instance, Northern Pygmy Owls often hunt songbirds in the daytime.
Now, you may be questioning:
What Do Owls Do In The Daytime?
That depends on a particular Owl.
Since most owls are nocturnal or crepuscular in nature, they treat the day as diurnal birds treat their nights.
I bet you are thinking:
Do Owls Sleep During The Day?
They do, but most species have been reported to take only short naps of 2-3 hours at a time.
These naps help owls stay alert to potential threats as well as rest properly at the same time.
Now, there is no rule that classifies owls as nocturnal or diurnal only.
But here are a few general observations:
- Large owl species that reside in forests or woodlands are mostly nocturnal. It may be that prey is abundant even at night, thereby, keeping the owls at rest till dusk.
Barred owls and Great-Horned owls are mostly nocturnal that sleep during the day.
- Small and medium-sized owls that live in deserts may hunt throughout the day. It may be that prey is scarce at night but often visible during the daytime.
For instance, Short-eared owls, burrow owls, and Pygmy owls hunt mostly during the day but sleep in short naps at night.
For instance, snowy owls, barn owls, and Hawk owls.
Why Would Owls Be Out During The Day?
This may involve
Like other raptors, owls are also opportunistic predators.
So if they wake up to a rodent walking near their nest, they will make sure to gulp it down!
Also, owlets are extremely hungry beings.
Therefore, during the breeding season owls often hunt throughout the day with casual nap breaks.
2. Potential Mates
Biologically, no animal can ignore a chance of food or a potential mate.
So, if an owl happens to find an attractive mate, it will pursue the owl regardless if it’s day or night
3. Threats/ Territorial Claims
Not many animals have the audacity to take down an owl.
However, owls have little space for brains and therefore, they lack common sense.
Also, their short temper does not help their cause.
This is why owls often see other owl species as prey or threat that must be eaten or deterred, even if it’s too sunny outside.
4. Scouting for Prey
Sometimes owls scout earlier than the actual hunt to lock down the location of the best possible dinner.
Typically, this involves owls flying around and looking for prey hurrying towards its hideout around dusk.
While adult owls don’t normally stick together in groups, younger owls are exceptionally playful.
Owls can see both during the day and at night as their eyes are extremely receptive to light signals.
Owls prefer to not be active during the day, as sunlight is too bright for them.
Most owls sleep during the day, but if an owl must eat, find a mate or resolve a threat it may fly outside even amid broad daylight.