Chickens are like nature's steady-cams*. They posses a remarkable ability to keep their heads stable even as their bodies move around. And it all has to do with their eyes.
The anatomic feature is demonstrated to great effect in this newly released Mercedes commercial**, which is presumably for some stability feature? We're not really sure. We're here for the chickens:
Pretty cool, right? Chickens – like most birds – lack the eye-control necessary to keep their gaze fixed on a stationary object while the rest of their body is moving. In humans, these compensatory adjustments are handled by the vestibulo-ocular reflex (VOR), an involuntary eye-movement that (and I'm simplifying here***) keeps your vision stabilized when you move your head. Lacking the oculomotor control that we humans possess, chickens have evolved to offload these compensatory adjustments to the muscles of the head and neck, instead. The result, as you now know, looks like this:
Or like this:
Or, as famously demonstrated by Destin of Smarter Every Day, like this:
Lots of birds do this. If you've ever seen a pigeon bob its head as it walked around, you've seen a bird compensate for the movement of its body for the sake of its vision (or, in scientist speak, you've seen "an optokinetic response to stabilize the retinal image"). Remember the Rotate Your Owl video? Same thing.