One theory is that the beak click helps the owl to locate prey. Owls are predators that hunt small mammals, birds, and insects in low-light conditions. The beak click may create a sound that echoes and bounces off the surrounding environment, helping the owl to determine the location of its prey.
Another theory is that the beak click is a form of communication between owls. Owls are known to make a variety of calls and sounds to communicate with each other, and the beak click may be one of these sounds.
Finally, it is also possible that the beak click is simply a byproduct of the owl's anatomy. Owls have a unique beak structure that allows them to open their mouths very wide, and the beak click may simply be the sound of the beak opening and closing.