Birds see a color that humans do not see

It is amazing that birds see a world quite different from our usual world, and thanks to a special camera that has the ability to simulate the vision of birds, it is possible to identify the characteristics of this distinctive aspect.

In addition to her horror, the photographs contributed to explain why birds can move between thick leaves in a very precise way, said Tessa Comandors, author of the report.

The author of the behavioral biologist Cynthia Tidor of the Swedish University of Lund, the team was seeking to discover patterns in nature that birds can see. They chose to show the truth of what birds see, because these organisms are highly visually oriented, depending on their vision to move and catch their food.

Unlike human eyes, bird eyes can monitor a fourth color. In fact, human eyes are characterized by three types of color receptors, or cones, which are sensitive to red, blue and green light waves. On the other hand, birds have a fourth future that differs in terms of the type of light waves that can be monitored, depending on their varieties.

For example, Australia's honeycomb has a fourth light-sensitive color, while parrot cones have the ability to capture more light within the ultraviolet portion of the visible spectrum.

To understand how these ultraviolet and ultraviolet light-sensitive cones translate visually, researchers have photographed the dense forest habitat in both Sweden and Australia. Researchers used a multi-spectral camera with filters designed to simulate what birds could see.

Multi-spectral images have clearly shown how ultraviolet receptors can detect large differences between the upper and lower leaves, making the position and direction of each paper clearly visible in three-dimensional form.

At the same time, the upper and lower surfaces of the leaf reflect similar levels of ultraviolet radiation. Therefore, the researchers believe that the differences are mainly due to the proportion of ultraviolet radiation reflected by the paper relative to the proportion of the movement.

UV rays are often reflected more than 25 times as much as they do.

In contrast, our small eyes can not show such differences because green light is transmitted and reflected equally, creating a lower level of contrast when seen through green waves.

Cynthia Tidor explained that ultraviolet vision helps birds fly and jump through thick leaves with the ability to move quickly and lightly. It also helps them to search for insects and spiders that hide on the bottom surfaces of leaves, while their ability to accurately identify these surfaces And quickly enhance accessibility to food.

The researchers noted that by adopting computer simulations, researchers discovered that the maximum variability at foliage level can be seen within short ultraviolet wavelengths in open and well-lit shadows, as well as longer UV wavelengths in closed, Low. This may explain why the fourth color observed by birds differs.

However, although the ability to see in four colors looks great and exceptional, this carries a number of negative consequences.

"One of the disadvantages of enjoying a fourth-type cone is that it will occupy an area within the retina that may be more devoted to one of the three other cones," said Tidor. "This could have devastating effects on the level of detail and sensitivity to dim light "He said.

"We have the conviction that what we see is reality, but only human reality," said biologist Dan Erik Nelson of the Swedish University of Lund. "In fact, other animals live in different worlds and realities, and now the world can be seen through their eyes, Discovering many secrets. "