If you have ever spent any length of time admiring an owl, whether this be in person or whether it was on TV, you will have most likely witnessed the funny little way they bob their heads. It can be quite endearing to watch as it appears the owl could be dancing but there’s a very good reason for this and it all revolves around the owl’s eyes, not just to look extremely cute!
I will be going into further detail below but to summarise quickly for those who want a short snappy answer… An owl bobs and rotates its head because their incredible eyes actually have their limitations and this is that they remain in a fixed position. This means that owls must move their heads in order to gather visual perspective.
When an owl wants to focus on something, follow its movements, figure out how fast it is moving or figure out its distance, they will move their head up and down, back and forth and often round in circular movements. This helps them to judge the position and the distance of its surroundings. By moving their head in this manner, they can decipher how the world around them fits together in their vision, and it sharpens their senses to be the incredible hunters that they are.
An owls most prominent feature is their eyes, and the anatomy of their eyes is fascinating . Their eyes are so large they cannot move freely in the eye socket and must remain forward facing, this is because they are held in place by a structure within the skull known as sclerotic rings which means their eyes are more tubular rather than round. This means their focus is extremely efficient as once they are fixed on something, their focus will stay there.
An owls whole visual perspective is managed by the movements of the head instead. If you look forward into the distance and focus on something specific and then begin to move your head, you’ll realise that anything closer to you will appear to move much more than anything in the distance. This is a small example of how a head movement helps the owl to figure out their surroundings. If an owl is watching their prey in a field in the distance, they can move their head around to decipher how far away the prey is and what is closer to the owl and what is closer to the prey in terms of surroundings. This is known scientifically as motion parallax and another description of this is the feeling you get when you are sitting on a train and looking out the window. The train is moving quickly and therefore anything close to the window is moving fast and becomes a blur whereas anything in the distance moves much slower and can be watched for much longer.
Since owls are unable to move their eyes, instead they have 270 degrees’ motion in their necks so they can see anything they need to from one single spot. Their incredible range of movement mixed with their extremely superior eyesight means that an owl can hunt a small insect from miles away and know the exact spot to swoop down. They can also hunt nocturnally so they also learn how to do all of this in the dark! Incredible, right?! In fact, it is this nocturnal sight that plays a huge role in why their eyes cannot move. Being nocturnal means the eyes need far more receptors attached to their eyes for this to be possible, which limits the movement of the eyes. I suppose the loss of movement isn’t such a bad thing when we consider what they gain from this. Especially since they can make up for it with all their head bobbing!
You can often notice that younger owls and owlets are more likely to move their head more dramatically and more often and this is because they are at the beginning of their development and haven’t figured it all out to perfection just yet. They are still learning how to gather their perceptual awareness.
I hope this has answered the question, I guess this could be considered the science made simple version but I have no problem with that! Hope you enjoyed 🙂