Was reading some of the archived articles and found the discussion on ‘why do pigeons bob their heads’ question rather interesting. Our dear Cecil maintains that it is a means to maintain balance. Others are opposed to this theory and are convinced that it has nothing to do with balance and all to do with eyesite and focusing abilities.
I was originally on Cecil’s side of this debate, but then it occured to me that when pigeons or chickens or other bobbly headed birds are CARRIED…they still bob their heads. However, if you block their vision with your hand, the bobbing ceases. They are focused on your hand (and I suppose the other eye would be focused on your chest) both of which would not appear to the bird, to be moving.
Hence, my brilliant deduction that the bobbing motion is INDEED a result of visual stimuli…not, in fact, balance oriented.
Anyone else have any enlightening thoughts on this debate?
That’s quite interesting. Next time I get to see live chickens I’ll try that experiment. But I really don’t see why their surroundings would make their heads bob. When you did this experiment with a bird, was it bobbing to the beat of your steps?
I don’t know how a bird’s eye actually functions, but the basic explanation was described in the original article.
As for my experience with it…I find that you don’t have to actually WALK to make the birds head ‘bob’…just hold it out in front of you and move them around. The bird will attempt to keep his head in a stationary location despite what his body does. It works if you move them forward, backward, in circles and even up and down…althought it’s less exagerated with the latter situation.
It appears that they will hold their heads in one location until the neck stretches beyond a comfortable position, then the head will ‘bob’ to catch up with the body. It maintains that position until the movement of the body forces the head to move again.
The only other way I can think to test the theory would be to actually blindfold a pigeon (or MY test subject, a chicken) and force it to walk around and see if the head bobs or not. Of course, I don’t know if this topic is important enough to warrent tormenting one of my chickens…but I’m game.
Just another observation here…but I noticed that while my chickens are walking around the yard their heads don’t actually ‘bob’ in time with their steps. There are generally two or more ‘bobs’ that occur within the period of one step. I have both giant and bantam (mini) breeds and the same action can be observed in both sizes.
Just another observation here…but I noticed that while my chickens are walking around the yard their heads don’t actually ‘bob’ in time with their steps. There are generally two or more ‘bobs’ that occur within the period of one step. I have both giant and bantam (mini) breeds and the same action can be observed in both sizes.
I’m seconding (thirding?) the stabilization theory. This stabilization actually developed to stabilize the heads of birds in flight. It then likely only feels natural for the birds to continue this behavior when moving in any fashion.
I’m a long time viewer of any scientific programs.
Yesterday I watched a deer bob its head while it moved slowly forward. I suspect that various prey animals (including pigeons) freeze head movement while the body is moving slowly (or stopped), in order to heighten sensitivity to any external motion which might warn of the approach of a preditor. If my theory is correct then the head bobbers will exclusively be animals which depend on rapid acceleration as a defence, since these are the animals which place a high premium on early detection of preditors. A mountain goat, skunk, etc., shouldn’t bob because they stand ground rather than flee. If my theory is correct, then the reason humans don’t head bob is that we aren’t quick enough to accelerate away from a lion, or tiger, so that extra milisecond of early warning wouldn’t help much.
My enlightening thought goes like that it is a respiratory draft in an accelerated creature caused by its outter feathers creating a heavier than air position for sight as it trots, but not (walk) otherwise there would not be any imbalance out of maintainance gramatically speaking.
I have the idea that it could be to provide a 3D image of the world around the pigeons (or other animals) head.
After each bobs, the brain could remember the last picture seen (using the idea of after images, which we as humans also experience) and combine it with the present one and thus compose a 3D image of the left and right side of the head.
So the pigeon can construct a 360 degrees 3D image of its surroundings. I am not sure about this, but being interested in 3D/stereo I am wondering if this could be the case…
Some birds, notably owls and raptors, have forward facing eyes that give them pretty good stereoscopic vision. If they don’t bob when walking, while birds with eyes on opposite sides of their heads do, that would add credibility to the theory.
Good point. Will take this into account in my work.
It is interesting to see an owl bobbing up and down while sitting. I think the bobbing up and down can make sure the 3D experience is in both x and y direction (stereo works best in the direction the two eyes are on a line: so in horizontal direction for normal eye positions).
In science they make matrixes of cameras to get a very good 3D image in all directions.
We just have a young kitten and she is also really using this technique (up and down bobbing of head) when trying to make a jump.
I will try to see if I can simulate this 3D image of 360 degrees (thus assuming after images in the brain). Perhaps I can do this with two 3D videos (played in sequence) on YouTube;-) Not sure yet, will think how to do it (and visualize).
