Like most birds, crows are tetrachromatic. This means that, instead of the RGB characteristic of humans, they perceive four color channels. So these are crows for you – black, and for each other they are very colored.
The resolution of the crow’s eye – both spatial and temporal – is very high. That is, according to the screen resolution and FPS, the corvids effortlessly make leather bags. Happy. But in the dark, Humans have a serious advantage: Ravens have poor night vision. This is a payment for good color perception and high resolution.
But the main feature of the crow’s eye is not at all in this. Due to their wide specialization, ravens have unique hybrid vision. I explain: in a rough approximation, in nature there are two types of vision: circular monocular and frontal binocular. Victim and predator (a picture with a decaying “owl-dove” is attached). Circular is characteristic of those who need to be on the alert all the time. The ideal option for them is a 360° VR camera to minimize the dead zone in which danger lurks. Pigeon, cow, duck, horse are great examples. Very often, the owners of such vision, looking closely, turn their heads to the right or left side in the object of interest, so that it is opposite the eye. But what is located in front of their nose, they see poorly, at the very edge of the retina.
In contrast, binocular vision covers a relatively small sector in front, but allows you to see it with both eyes, and most importantly, due to the stereo effect, it makes it possible to accurately determine the distance to objects in the field of view. This is very important when attacking (and also, for example, when jumping from branch to branch). Examples: an eagle, a dog, a cat, an owl (SUDDENLY, for example, a monkey, because measuring the distance is more critical for her than a circular view). Binocular holders, looking closely, turn their nose (beak, face) to the object of interest.
Let’s get back to our bara… crows. The location of the eyes, as well as their mobility, which is not quite typical for birds (the eyes of the birds are large, the head is small, and there is almost no room for the driving muscles), give the crows a unique perk: hybrid vision. Look again at the picchu above. The crow can do both of these modes. The eyes of the ravens can either move apart, providing a view of almost 360 ° (in fact, somewhere around 320 °, according to my observations, a narrow sector of the “blind zone” remains from the back of the head), or come down literally to the tip of the beak, if they require. Thus, having the possibility of a circular view, the crow is not without the advantages of binoculars; while a chicken or a duck pokes its beak into the trough at random with an error of a couple of centimeters to the left and right, the crow takes out a mote from the human eye without any problems, because despite the intimidating appearance, the crow’s beak is a high-precision instrument on a stabilized platform, equipped with high-resolution cameras. Threaded a needle? Now imagine that your hands are not trembling, and your eyes (with the option of focusing almost point-blank) are located on your fingers. This gives the crow a significant bonus to subtle manipulation with its beak, and the ability to instantly switch to a circular view does not allow the bird to be taken by surprise. In addition, binocular vision gives a noticeable bonus to maneuverability in flight, because the built-in rangefinder greatly facilitates the calculation of the trajectory.
Author: Daniel Lee