How come people have different answers to how many degrees owls can turn their heads around?

The number of degrees an owl can turn its head around is a matter of debate. Some sources claim that owls can rotate their heads up to 270 degrees, while others claim they can only rotate them 180 degrees. The discrepancy in these claims may be due to the different definitions of "turning the head around." Some people consider the ability to completely rotate the head around so that it is facing backward to be the true measure of head-turning ability, while others consider any rotation of the head to be a head turn.

In reality, owls have a remarkably flexible neck that allows them to rotate their heads a great deal, but they cannot completely rotate them around so that they are facing backward. The structure of the owl's neck is such that it is reinforced with tendons and ligaments that help to keep the vertebrae from completely rotating. This is important because if the owl were able to rotate its head too far, the blood vessels that run up the neck could be damaged.