Currently, there is no precise way of telling how far or how good a hawk can see.
However, hawks have large territories exceeding up to 20 miles in diameter.
Did you know they have been observed to chase after prey from at least 2 miles away.
Which gives us an indication,
Hawks can supposedly see from at least 2-miles to about 20-miles away.
“Is that good?”
Unquestionably, yes.
You see, a human can see only as far as 3-miles away, that too if nothing obstructs his view.
How Good Is a Hawk’s Eyesight?
It’s about 4-8 times better than a human eyesight.
Again, that’s just an estimate.
It would have been great if only a hawk could sit in the doctor’s office and give a full eyesight evaluation.
Clearly, that seems highly unlikely. Lol!
But that didn’t stop ornithologists.
So,
How Did Scientists Estimate A Hawks Eyesight?
By observing the hawk behavior in various circumstances and settings.
In one such experiment, ornithologists got hawks in a big garden-sized cage.
Then, they set up perches against two opposite walls.
They projected one wall with a screen of landscape and the other wall with the same landscape but with small grid lines.
Whenever the hawks approached the landscape without grids, they were rewarded with some food.
But when they moved towards a grid-lined landscape, then they were not rewarded.
Once the hawks got conditioned to always approach the wall without grids, the scientists started to narrow down the grid lines.
So much so, that eventually the humans were unable to see the lines.
However, the hawks still approached the landscape without grids.
This showed their eyes had a better resolving power than a human eye.
Or it could mean
Hawks can distinguish objects better than humans do.
But then, some hawks never approached a vole merely 1-mile away.
Also, some hawks never jumped on a rabbit sitting right under their perch.
Besides, we cannot simulate all kinds of natural possibilities with caged hawks.
Therefore, the estimations we do are somewhat conditioned responses.
So,
Perhaps, hawk eyes function differently than human eyes.
While comparing the two eyes is not like comparing apples and oranges.
But it may be something like comparing oranges and tangerines.
And so,
Humans cannot see how a hawk sees.
However, we can certainly try to understand how it works.
What Makes Hawk Eyes Excellent?
Here are the most prominent features involved:
1. Eye Size
While human eyes are slightly larger than hawk eyes.
However, human eyes don’t even weigh 1% of their total body mass.
Meanwhile, hawk eyes comprise about 15% of their total body mass.
Additionally, hawk eyes take most of a hawk’s brain space, leaving limited space for cranial nerves.
A Hawk has enormous eyes relative to its body mass, indicating the significance of eyesight for this raptor.
This makes sense as hawks rely mostly on their eyesight for hunting.
Since eyes create vision by collecting light.
Therefore, bigger eyes suggest a better ability to gather more light.
Consequently, a better vision with dim lights.
Or,
Hawks can see in the dimmest of lights because of their large eyes.
Though they cannot see in the dark, this explains how hawks can hunt in the early morning hours as well as late evening.
2. Structural Variations
Unlike humans, hawk eyeballs are shaped more like ovals with flattened lenses.
This means that there is more space from the lens to the retina lining. Consequently, the focal point of the eye. And so,
Hawks can focus on objects farther than a human can see.
Besides, hawk pupils are bigger than human eyes, allowing more light to enter their eyes. Thereby, creating better graphics.
The pupil is rounder to produce a wholesome view.
3. Color Perception
The retina is a light-sensitive membrane on the back of the eyeballs.
It contains two types of cells:
- Rods: Cells that are responsible for vision in low light.
- Cones: Cells that help in perceiving colors.
The number and complexity of these retinal cells determine the visual abilities of any animal.
For instance, owls lack cone cells and have highly developed rods.
Therefore, they can see in the dark but cannot see any colors.
Now, hawks have highly developed cone cells and adequate rods.
So, we can say:
Hawks are not color-blind, and they can see in dim lights but never without light.
The orientation to colors has been loosely observed with hawks choosing colored prey over other available prey.
Seemingly, hawks can also see colors of UV-spectra that humans cannot see.
This means hawks can see the urine of prey animals that appears colorless to us.
Also, they can probably see the heat waves coming from a living body.
Hawks may be able to detect prey through heat emitted from their bodies.
Pretty awesome right?
4. Position
The position of the eyes mostly determines the extent of binocular vision.
For instance, human eyes are fixed face-forwards, limiting human view mainly to the front.
But this also gives maximum focus on a singular object, adding fine details.
In contrast, prey animals have eyes on the back of their heads.
For instance, goats have eyes on the upper sides of their heads.
This allows them to observe their surroundings for a predator while feeding downwards.
Just like humans, hawk eyes are also fixed facing forwards giving them a binocular view.
However, hawks can also have monocular vision.
Hawks can see two different objects at a single time using both their eyes.
This allows hawks to scan an area better than normal vision.
5. Eye Protection
Hawks have three eye-protecting membranes.
Two of these, function the same way human eyelids do, closing the eye from above and below.
The third membrane called the “Nictating membrane” is absent in humans.
It covers hawk eyes from sides.
However, this membrane is partially transparent, allowing the hawk some vision, while protecting it.
Hawks use nictating membranes to protect their eyes from dust, winds, rain as well as their babies.
The eyes are almost completely fixed in well-adjusted boney eye-sockets.
These bones also give the hawk face a fierce appearance.
This is precisely why hawks look grumpy all the time, but I assure you they have nothing against you.
Anyways, all these adaptations give hawks exceptional visuals for hunting.
Still owing to their size and fixed positions, hawks cannot move much of their eyes as humans do.
So, you may be wondering:
How Many Degrees Can a Hawk See?
About 180° in both horizontal and vertical directions.
You see, hawks have forward-facing fixed eyes giving them some degree of overlapping vision to create a binocular view.
It is much like what a human sees.
But then, humans can rotate their eyes more freely, but hawks cannot.
However, humans can rotate their heads to only about 90°.
Meanwhile, hawks can rotate their heads to 180°, as well as to and fro.
They have two different focal points in their retina to see two objects in the same direction, with a single eye.
Hawks compensate their fixed eyes with their head movements.
But, then hawks differ in sizes from few grams to 2 kgs.
Also, they differ in their habitats and prey preferences.
And so, hawks have somewhat different visual requirements depending on their species.
A hawk’s capacity to see also differs among species.
Now, there are two major groups of hawks.
It seems that they have evolved their sights according to their habitats.
These include:
1. Buteo
These commonly inhabit open spaces like deserts, grasslands, and pastures.
The eyes for this group are arranged farther apart from each other, giving more visuals in a fixed frame.
Also, their eyes are almost immobile, giving a stable view.
For instance, Red-Tailed Hawks have relatively small binocular overlaps about 33° and wider blind areas typically 82°.
The eye muscles allow intermediate movement of approximately 5°.
2. Accipiter
These hawks are prevalent in woodlands so, they need more focus on a singular object than scanning a wider area.
That is why their eyes are located somewhat closer.
For instance, Cooper’s Hawks have binocular fields of 36° with narrow blind areas 60°.
Additionally, their eyes allow a movement up to 8°.
These Cooper’s Hawk can see objects held in their beaks through the back and forth motion of their eyes.
How Far Can Hawks See Their Prey?
Likely, at 2-4 miles distance.
Earlier, when we estimated how far a hawk can see, we were only wondering how far those eyes can work.
It’s just like wondering if a human can see the ocean from far away.
But a human may still not see a small boat some 10 miles on that ocean.
Now, you may be thinking something like,
“But why would a hawk not detect a rabbit sitting right under its cere?”
Again, that 2-4 miles range is an estimate and not an actual value.
You see, when we say a hawk will see a rabbit from 2 miles away, we are saying that it can see prey that much farther away.
However, a hawk may scan an area looking for any prey, and not just for rabbits.
Or,
The hawk does not know there is a rabbit below its perch so, the hawk is scanning the entire area to find anything to eat.
Perhaps, the hawk smelled a rabbit or saw some ultraviolet glowing rat feces.
But it still does not know where the animal is hiding.
And still, the hawks eventually dives at that running rabbit.
Ornithologists explain that:
Hawk brain is wired for detecting movement rather than observing prey.
Philosophically, humans see but hawks notice.
So,
When that hawk screams in distance, all the prey animals stop moving.
Probably, hoping and praying, “Please don’t notice me, please don’t notice me”.
And so, that rabbit under hawk’s perch is so still that it’s barely noticeable.
If it moves an inch, the hawk will come, and the rabbit will get killed and eaten
But then, eventually, a rabbit does move, and the hawk chases it.
I imagine the hawk saying “Drop on your knees”.
And the rabbit’s last words being, “Too late, well, I am dead”.
This is precisely why no animal likes playing Hide and Seek with hawks.
But then,
How Does Prey Size Affect Hawk Eyes?
Finding a larger prey scuttling away is easier than finding a smaller one.
Now, there is no exact way of calculating how much size will be visible from a certain distance.
It may vary from the color of prey to the type of hunting landscape.
But most hawks dive on a running rabbit from 1-2 miles distance.
Now, rats are about 1/4th the size of a rabbit.
So, if a hawk can see a rabbit from 1-mile away, the distance will be shorter for a rat.
So, a hawk will likely see a rat from half a mile to 3/4th of a mile (0.75 miles).
Now, all these may have sounded like hawks cannot see much.
But let me state again:
A hawk can see nearly everything around it in about a one-mile radius. It can focus on two different objects at the same time using two eyes. But it also has binocular vision. Also, a hawk can see an object while focusing on its background.
So, having hawk eyes gives them a truly magnificent view.
Wrapping Up
A hawk can see as far as 20 miles.
It can focus on objects in the same direction as well as see two objects at the same time.
Hawks can see about 8 times better than the human eye with more vivid colors.
However, they can’t see in the dark
Hawk eyes are wired for seeing a moving object.
Overall hawks have some pretty awesome vision which makes them really cool raptors!
Here’s some related articles about hawks which I’m sure you’ll find interesting so be sure to check them out
How long do hawks stay in one area?
Difference between a hawk and owl
