Birds are masters of wonder. The anatomy of their feathers fascinates usits millimeter flight hypnotizes us, and their singing has the ability to calm us down. We have never stopped studying birds, since they have capacities that continue to surprise us: for example, that of guide their flight from the «compasses» they have in their eyes.
But have you ever wondered how a bird sees the world?
These winged beings can perceive ultraviolet rays. Contrary to us, who only have three photoreceptor cells in the retina to capture light waves that are converted into the colors blue, red and green, the birds have four of these neurons eyepieces. This gives them the ability to perceive ultraviolet rays.
To find out why the gaze of birds and other species has evolved in this way, a team of researchers from the University of Lund, in Sweden, designed a camera to capture images of vegetation as a bird would see it. The camera recreates the spectral sensitivity of different bird species, allowing scientists to compare different gazes and their variants: for example, between cells that capture ultraviolet and violet, and generating another series of images of vegetation captured in blue, green and red.
Thus, the researchers discovered that the UV vision of the birds allows them to better see the contrasts of the vegetation. Dan-Eric Nilsson, Professor at the Department of Biology at Lund University, explained it as follows:
What appears to be a green mess to humans consists of pale, easily distinguishable leaves to birds. No one knew this until this study was done.
This helps the birds to be able to see better among the foliage of their habitats, which are usually dense and dark jungles and forests; In order for birds to fly over them and find food, they need to perceive the ultraviolet rays that radiate from the leaves.
Knowing this not only helps us to better understand the evolution of birds and their gaze, but it is also an exercise in empathy necessary to understand any other being. And what better if it is one that dazzles us as much as the birds.
* Images: 1, 2) CC; 3, 4) Lund University
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