There few things I enjoy more than chicken head tracking. Check out this new Mercedes-Benz commercial! Apparently, the video is highlighting the The Magic Body Control system which combines the "advantages of the Active Body Control (ABC, which is an active suspension system) with the newly-developed Road Surface Scan function, which is a stereo camera that scans the road ahead and prepares the car's suspension for uneven surfaces." (If you are interested in the car-related stuff, you can read more here.) But, on to chickens...
Here's perhaps the most "famous" chicken-head tracking video:
Here's a post on npr where Krulwich ponders this same topic. I tried to find some scientific sources to explain why this happens, the closest I found was an article entitled "How some birds keep their eyes on the prize" (which was eventually published) explaining the "aerodynamic trick [which] enables a bird to attain stabilized vision beneficial for the inspection of the environment."
Apparently, NASA originally did research on the vestibular sensory system of owls, back when they were looking at the effects of space travel on humans. As this post does a good job explaining,
It works like this: the three semicircular canals sense rotational movements and the otoliths sense linear accelerations. This information is integrated by the brain and used to help control eye movements so we don't become dizzy and to help our postural muscles keep us upright.So, humans participate in head-tracking, too, but birds (and some other animals) are just ridiculously good at it. (The aforementioned post also includes an owl-head tracking video, compliments of this NASA research.) You can read WAY more about the inner ear and your vestibular system on this NASA page.
Finally, according to some sources, the chicken head tracking commercials are not all that original.