What kind of pupils does a goat have? Goat eyes

Answered by veterinary ophthalmologist, microsurgeon, Ph.D. Konstantin Perepechaev

The pupil is essentially a diaphragm, which, by contracting or expanding, regulates the flow of light onto the retina of the eye. In addition, its size and shape affect the field of view and the quality of the image obtained on the retina. Different animals - depending on the ecological niches they occupy, location in the food chain, lifestyle and type of nutrition - these characteristics differ from each other.

Herbivorous ungulates (goats, sheep, cows, antelopes, horses, etc.) in the food chain are always victims of any predators. In accordance with this their visual analyzer forms visual information, and the brain processes it from the point of view of the “prey mentality”. Any fast-moving object, even if it is not clearly visible, may well be an attacking predator, so any unexpected movement immediately causes the herbivore to protective reflex: defense and/or flight.

All herbivores have large, slightly bulging eyes, located almost on the sides of the head. This provides the widest field of view. For example, overall width A horse's field of vision is approximately 350º. Thus, the horse does not see only a narrow sector directly behind the poll. (In the article “My Planet” you can read and even observe how a horse, bee, cat, etc. see the world.)

IN daytime in strong light, the eyes of goats and sheep look like narrow slits; in the dark, the pupil dilates, taking on the appearance of rectangles or even squares. The long horizontal pupil enhances the image quality of objects in front and behind the animal, making it easier to move quickly over uneven or mountainous terrain

The rectangular, or rather, horizontal-oval pupil of herbivores just helps them see the widest possible panoramic picture around them. Due to the stretched shape of the pupil, a goat, for example, has a viewing angle of almost 340°, that is, when grazing, it calmly observes what is happening around it, without even raising its head. In the daytime, in strong light, the eyes of goats and sheep look like a narrow slit; in the dark, the pupil dilates, taking on the appearance of rectangles or even squares. This mechanism contributes to the same thing - better review in the dark. A goat, like other animals with such pupils, is able to notice a moving predator almost behind itself at night. When a predator appears in the field of view of at least one of the goats, the entire herd will have time to escape.

According to latest research The long horizontal pupil also enhances the image quality of objects in front and behind the animal, making it easier to move quickly over uneven or mountainous terrain, and also helps the eye capture more light along the surface and less glare overhead. Additionally, by observing zoo animals grazing, researchers discovered that the animals' eyes rotated so that the line of the pupils always remained horizontally aligned, even when the animals' heads were tilted vertically downward.

And fainting goats competing for attention can't distract attention from the look of the goats' eyes. Their horizontal, rectangular pupils appear alien compared to the round pupils of humans and dogs and the vertical pupils of cats. Why do goats' eyes look this way? And for that matter, why do cat eyes look the way they do?

In a new study, vision scientist Martin Banks found that the shape of an animal's pupils is a clue to its place in the food chain . Banks and his team examined the eyes of 214 various types land animals, and found a clear relationship between the shape of their pupils and their ecological role.In predatory animals that ambush their prey, as a rule, vertical section pupil, while herbivores, which are prey for other animals, have horizontal pupils.The predator-prey distinction based on pupil shape suggests that both hunters and those being hunted derive some advantage from a specific pupil type.

To find out what these benefits might be, the researchers analyzed the abilities of the two pupil shapes and how they might serve the different visual needs of predators and prey. Goats and other herbivores (eg, deer, large cattle and elk), which are hunted by predators, have a fairly simple strategy to avoid being eaten: pay attention to danger and run if they see it.

To support such a strategy, their eyes must be able to do two things. “On the one hand, these animals must have panoramic vision in order to detect predators that might approach different directions,” the researchers write. “On the other hand, they must see straight ahead clearly enough to move quickly over potentially uneven terrain.”

Horizontal pupils help here because their shape creates a sharp panoramic view that is wider and shorter than what others get by having round or vertical pupils, and such a pupil allows the animal to see almost everything around it. A long horizontal pupil also improves the quality of images of objects in front and behind the animal, and also helps the eye capture more light along the surface and less glare overhead.

Of course, these benefits don't work if the pupil remains oriented in the same way and becomes vertical when the animal lowers its head to graze. However, after observing grazing animals at the zoo, researchers discovered that their eyes rotate in such a way as to remain horizontally aligned when their heads are in an upright position.

The researchers say the long horizontal pupil seems ideal for these animals. In other words, goats strange eyes because they help them survive.

At the same time, the team found that vertical, slit-shaped pupils help small predators such as ambush and judge the distance to prey and other objects so that they know how far they should jump.

“For those species that are active both day and night (for example, domestic cats), the pupil size provides dynamic range"needed to help them see in dim light and also to prevent them from going blind in the midday sun," Martin Banks said in a statement. “However, this hypothesis does not explain why the cuts are placed vertically or horizontally. Why don't we see with diagonal cuts? This study is the first attempt to explain this."

Round pupils, like those in humans (or like those in adult cats), tend to belong to carnivores. The eyes, which are slanted to the sides like those of goats, belong to animals that graze in the pasture and are prey. Using computer models, the researchers confirmed that lateral eyes produce a much wider field of vision than eyes like ours.

Researchers say that next accent will be done by them by studying the shape of the pupil of animals that live in water. This will be much more difficult, since the lateral position of the eyes of a sea creature, such as an octopus, for example, can indicate that it is both a predator and a prey.

If you found our article interesting, please leave a review and share it :) Thank you!

The shape of the pupils of animals is predominantly round, but there are plenty of exceptions. One of these representatives is found among the artiodactyls - the goat (goat). She has rectangular pupils, turned horizontally. In bright light they narrow to the point of forming a line, and in the dark they expand to their maximum. The latter determines the origin of the expression “bug-eyed goat.”

U large number In ungulates, the pupils are rectangular in shape. We exclude the giraffe.

Who else has

Let us list other animals endowed by nature with rectangular pupils:

• cow, horse, llama, hippopotamus, mongoose, octopus;
• a sheep (ram) is a relative of a goat, which determines the shape of the pupils in question;
• shark, stingray - looks like a rectangle with vertical arrangement. Occurs in some species;
• gecko - less reminiscent of a regular rectangle, but its shape is elongated, which allows it to be included in the list. Not all members of this family of lizards have such pupils;
• amphibian (aka frog) - depending on the type of amphibian, the pupils are located horizontally or vertically.

Why are the pupils rectangular?

The explanation here is simple. Let's take a goat for example. She needs to constantly receive food - she grazes. Previously, goats were wild and were hunted by other animals. In this regard, there was a need to survey the surroundings without lifting the head from the ground. This led to the dilation of the pupils horizontally. The viewing angle began to reach 340 degrees without turning the head.

The same explanation applies to other representatives of the animal world with rectangular pupils.

Almost all people have seen a goat at some point in their lives. But hardly anyone had the desire to look into her eyes. And if you looked in, you would be somewhat surprised to see the shape of the pupils. Read on and you will find out what kind of pupils a goat has and what is remarkable about them.

Pupil shape

Most often, people believe that everyone has pupils. This opinion is formed by analogy with the human eye. But this is not so, in many animals the pupil has a completely different shape, for example, the pupils of a goat are located horizontally.

During the daytime, they look like a narrow slit. When dilated, the goat's pupils turn into rectangles.

Why do you need a rectangular pupil?

Due to this shape of the pupil, the goat’s viewing angle reaches 340 degrees without taking into account the rotation of the head. That is, when grazing, the goat has the opportunity to observe what is happening without raising or turning its head. For comparison: a person’s vision is only 160-180 degrees when the head is motionless.

In the daytime, in strong lighting, the goat's pupils are greatly constricted and look like just slits. serves mainly to protect the goat's eyes from taking on the appearance of rectangles with the arrival of twilight and night time. In a very dark room or with strong excitement, the goat has square pupils - this is achieved by further dilating the pupil. This mechanism contributes to the same thing - better visibility in the dark. A goat, like other animals that have the same pupils, is able to notice a moving predator almost behind itself at night. This helps the animals have time to notify other animals in the herd and escape, avoiding death.

The pupils of a goat give the animal the opportunity to feel relatively safe, because, having almost all-round vision and a tendency to live in a herd, a group of goats can graze calmly. If a predator appears in at least one of the goats, the entire herd will have time to escape.

It is interesting that, having such remarkable abilities to see around them and in the dark, goats are unable to judge the distance to various objects. These animals cannot even correctly determine the direction of movement, since their spatial vision is extremely poorly developed.

The emergence of the pupil shape of goats

Such a pupil was formed in goats and other artiodactyls millions of years ago. Initially, most likely, the pupils were round, but with constant exposure to the sun, the pupil began to narrow. Since animals feed with their heads low, the pupil began to narrow precisely at horizontal direction, in order to give them the opportunity to survey the horizon without interrupting their food. Gradually, muscles formed inside the eye that close the goat’s pupils to the slit in bright light. In the dark, these muscles relax so that animals can feed at night with the same quality of vision.

Who else has a rectangular pupil?

Among domestic animals, sheep have pupils of the same shape. In the wild, almost all artiodactyls have this feature. Except artiodactyls rectangular pupil Oddly enough, octopuses and mongooses also have: they also need to protect their pupils from bright sunlight for night life. And controlling the horizon for these living organisms is also a vital task.

Various types of pupils reflect different image life, different habits and needs. To understand why and why pupils have different shape, we just need to analyze what we know about living beings. And then the horizontal rectangles of a goat, the vertical slits of cats, and the predatory squint of a shark will become clear. You just need to look into the eyes of someone other than yourself sometimes.