Have you ever wondered if other human beings have the same vision of reality as yours? I mean, we are of the same species, and we are constituted basically under the same mold; so, our eyes are very similar, right? However, this doesn’t really mean that our vision is exactly the same as that of others. Now move that scenario to other species, whose physical makeup varies so much from ours. You would expect to find that even the same landscapes our eyes capture are completely different for other species, and science confirms this. The eyesight of hummingbirds has a great chromatic capacity; they are capable of seeing colors that we humans cannot even imagine!
The human eye has about 110 million cells called cones. In the human eye, there are three types of cones, each capable of capturing different spectrums of light: red, green, and blue. This is the system known as trichromatism, which allows us to distinguish approximately one million different hues. Of course, this varies from person to person since vision depends not only on the eyes but also on the brain’s interpretation.
But as you might expect, other species have evolved according to their survival needs. Vision plays an important role when it comes to survival. Bees, for example, are also trichromatic, but unlike our eyes, their cones capture ultraviolet, blue, and green light. This is why they live immersed in an ultraviolet world full of objects that seem to flash all the time.
How does the hummingbird’s vision work?
Hummingbirds, on the other hand, have taken their eyesight to an even higher level. They have a tetrachromatic system in their eyes, composed of four types of cells specialized in capturing light. For this reason, they can distinguish a wide range of colors, including non-spectral ones. So, not only are they able to visually distinguish ultraviolet light, but they also see colors that humans cannot perceive.
Research from the Department of Ecology and Evolutionary Biology at Princeton University concluded that the vision of the hummingbird is essential for signaling and foraging. Other types of birds also have tetrachromatic systems in their eyes, and it is even believed dinosaurs had it too.
“This color vision system is the norm in birds, some fish, and reptiles, and almost certainly existed in dinosaurs. We believe that the ability to perceive many colors outside the (human-range) spectrum is not just an ability of hummingbirds, but a widespread feature of animal color vision,” explains Stoddard, leader of the research.
And here we can highlight the fact that birds need to travel long distances without getting lost. Albert Einstein himself theorized about bird migrations, and he thought that vision would play a fundamental role in their sense of orientation. In conclusion, reality is not what we see per se, or at least it is not the same reality for all living beings, much less for all species.
Text courtesy of Ecoosfera
Translated by María Isabel Carrasco Cara Chards
Photos: Pexels: Philippe Donn/ Frank Cone
