People have always been interested in how their pets see the world around them. For example, budgies. What colors do they distinguish? Do these birds see in the dark? Are they really, looking in a mirror, can distinguish their reflection in it? The answers to these questions can be found in the article.
Features of the view of parrots
Vision is the main receptor for the perception of the world for budgies, with which they have the opportunity to navigate in space. The main organ of vision is the eyes, arranged in such a way that parrots can see almost 360 ° around themselves, while each eye can focus on different objects.
The large size of the eyes relative to the size of the body allows you to see the picture in close up, while all the details are visible in great detail. And the changed shape of the lens and its movement relative to the cornea make the picture contrast. In addition, budgies can see 150 frames per second, people - only 24 frames, and dogs - about 15. This ability allows birds to distinguish even the smallest objects at high speed.
To understand how budgies and some other vertebrates see, scientists conducted a series of studies. It should be noted that until the beginning of the 70s of the twentieth century, the fact that many animals that are not mammals can distinguish the part of the spectrum invisible to the human eye in the near ultraviolet was still not known.
Color sensitivity
A person can judge how budgerigars are seen based on their own experience and the research of scientists conducted in this direction. Therefore, it is very difficult to accept the fact that parrots can see this world somehow differently. The visual system of a person is imperfect, but the ability to see allows him to perceive the world in three dimensions and move freely in space, while distinguishing the color of objects.
However, many animals: birds, reptiles and insects - are able to recognize ultraviolet rays. Experienced, scientists were able to find out what colors the budgerigar sees. To have an idea of the process of perceiving color and the contours of objects, you need to understand how it works.
Objects absorb light only at specific wavelengths; they reflect everything else. The perception of light goes through nerve impulses, which are caused in the brain by the influence of different wavelengths of reflected light rays.
The ability of vertebrates to distinguish colors is due to the presence of cones in the retina, which are a layer of nerve cells. It is they who transmit visual signals to the brain. In each of these cones is an opsin protein pigment, which is associated with retinal, a substance related to vitamin A.
When a pigment absorbs photons of reflected light, the retinal, under the influence of this energy, changes its shape and starts a series of molecular transformations that activate cones, and then retinal neurons. One of the types of these neurons sends an impulse along the optic nerve. And then the information is transmitted to the brain.
So that the brain can see the color, it needs to compare the reactions of several types of cones, in which there are different pigments. If more than two types of cones are present in the retina, then this will help to better distinguish colors. There are three types of cones in humans, and four in budgies.
It’s almost impossible for a person to understand what exactly and how budgerigars see. After all, experiments by scientists have shown that birds use all four types of cones.
What does the budgerigar see
Birds are not only able to see in the near ultraviolet, but they can also distinguish colors and shades that people cannot even imagine.
In order to at least partially come to an understanding of how budgerigars see, scientists, researchers have proposed the following incredible analogy. If human trichromatic vision is a triangle, then tetrachromatic bird vision requires another dimension for their trihedral pyramid - the tetrahedron. So, the space above the base (human triangle) of the tetrahedron is the whole variety of colors, inaccessible to humans, but natural for birds.
How parrots distinguish each other by gender
Parrots, along with other types of birds, derive considerable benefit from this variety of color information. Males are almost always colored much brighter than females. When it was already proved that birds see in the ultraviolet, then a scientist of the University of Minnesota Muir Eaton as an experiment studied 139 species of birds.
He measured the wavelength of light, which was reflected from the plumage of identical in color (in the eyes of a person) heterosexual individuals. Eaton's conclusion was overwhelming. In 90% of the investigated cases, birds correctly understood the difference between males and females.
Studies by other scientists on different continents have shown that colors with an ultraviolet component are often found in males in the “mating” plumage participating in demonstration courtship. Females prefer those males whose plumage reflects more ultraviolet rays.
As budgies see in the dark
In the process of evolution and breeding of these birds in an artificial way, they lost the ability of night vision. Do budgerigars see in the dark? Almost do not see. In the dark, parrots usually sleep.
If a human ancestor had not lost one type of cone pigment during evolution, and human vision would now be tetrachromatic, like in birds, most reptiles and fish, I wonder what we would see? What colors and shades would be available for us? Surely the world around would become brighter, more diverse and enchanting than we used to see it.