Like other nocturnal birds of prey, owls have very keen vision , especially in low light conditions. Their eyes , however, remain fixed , so they have to rotate their neck to follow the movement of objects . In fact, they manage to turn their heads up to 270 degrees, and this without affecting their tendons and without excessively compressing their blood vessels, so the blood supply to the brain is not interrupted.
To do this, they have developed several anatomical adaptations. A group of researchers from Johns Hopkins University, in the USA, has discovered, for example, that one of the main arteries that feed the brains of these animals passes through cavities in the vertebrae ten times larger than the own blood vessel . Air pockets form in the remaining space that allow it to move smoothly when the bird twists its neck.
The way in which its fourteen cervical vertebrae are arranged – human beings have seven – favors this prodigious flexibility , which is also influenced by the fact that they only have one point of articulation between the skull and the first vertebra, which is known as occipital condyle. On the contrary, we have two.
