ELI5: Why do birds have “robotic” movement?

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Not an expert but I asked the question before and the answer I had was this. The brain of the bird is made to mostly perceive movements (like the raptors in Jurassic Park). So in order to see those movements they try to stay still most of the time. When they have to move, they will move most of their body and keep the head at the same place so that they can still perceive movement in reference to them. Then they will quickly readjust when they can’t do that anymore, giving that weird look when they do. try to google “chicken stabilizer” for illustrations of how they try to always keep their head still in relation to their environment.


Not an expert, it’s based on my curiosity and interest in birds. Correct me if I’m wrong. Birds have a different vision than us as a necessity. They fly, dive bombs, go fast and move through obstacles all the time. As such, having the ability to stabilize images is paramount. There are multiple ways to do so. Basically, to see something, your eyes need to see it, transmit it to your brain, and your brain treat it. The faster you move, the faster you need to treat images. The more complex your sight, the harder it is to treat. On top of that, you need to account for the movements of the body. All of that is a long and complicated process. We, humans have simplified it by having a shorter sight. We don’t need to see far and we didn’t need high speed treatment. So we can stabilize images really well, and treat them very well. Birds on the other hand go fast and need to see far to avoid not only the obstacle in front of them but the obstacle behind the original obstacle. They on the other hand have given up a lot of their ability to stabilize images. Instead, they’ve learned to stabilize their head. If you have no vibration to account for, you don’t need to care for it. As a result, birds usually go for burst of movement then stabilize to see again. They’re not blind but when they jump around, but they have a much harder time focusing and seeing properly. So to avoid times with lack of awareness, they move fast and in burst so they can stabilize after and check their surroundings again.


Birds can’t move their eyes inside the sockets. They’re stuck facing one direction. Lots of birds do head movements to look at the same object from different angles, which gives an effect similar to depth perception.


Birds’ vision gets very blurry when they move, so they try to keep their head as still as possible. When they’re walking, they bring their head forward quickly, then their body follows while the head stays in place, giving them some time to see clearly, then they quickly bring their head forward again, repeat. When they look around, they also move their head in quick bursts so they lose their clear vision for only a moment at a time. They also can’t move their eyeballs around, so they have to move their heads in these quick bursts every time they focus on something different.


Not an expert either, but that’s probably the result of 2 main things. – Birds can see “faster”. Kind of they see “more frames par seconds” – They have a wider field of view. Combining both they only have to turn their head less, and when they turn their head it might seem “quick” for you, but it’s just standard for them. We tend to move our head when we watch a moving object, for example, a car, because we tend to have our head facing what we focus. That’s white not the case for birds who can see a shit load all around their head. That’s actually a behavior that could be extended so reptiles too and maybe things like rodents too. I presumed you where speaking about when they are on a branch and looking around. Because they look nothing like robots when they are hopping around or flying 😀