Slow mo walking chicken video, watch the head movement.

[Spinnor]

The video,

http://www.youtube.com/watch?v=XDCk0DaNwiQ&feature=results_video&playnext=1&list=PL28AFB6F1D7079B62

Observation of our chickens, when a chicken walks the head is kept motionless and then moves quickly to a new position, repeating over and over again as the chicken moves forward. Interesting to watch, there must be a reason?

So keeping the head motionless is best why? Is it a survival thing?

Do chicken eyes move in their sockets?

Thanks for any help!

 

[Spinnor]

See also, this is the best,

http://www.youtube.com/watch?v=PTpX21IJZz0&feature=related

 

[Spinnor]

Looks like pigeons do it also,

 

[aroc91]

http://www.ccmr.cornell.edu/education/ask/index.html?quid=472

It seems they're not as adept at detecting movement while they, themselves, are moving, so they need their head to be still to get a clear image. I've found that in addition to chickens and pigeons/doves, ostriches do it to. I think it'd be interesting to compare visual cortices between species that do it and species that don't.

 

[Ouabache]

Observation of our chickens, when a chicken walks the head is kept motionless and then moves quickly to a new position, repeating over and over again as the chicken moves forward.

After your post, I observed several wild turkeys walking across the pasture. They made the very same head movement.

 

[lisab]

Funny thing about chickens (and maybe other species)- when you pick one up and walk in the direction its head is pointing, it does the same head movement as it's being carried. But only up to a certain speed, then the head is still.

 

[aroc91]

I've looked at a few phylogenetic trees (man, are they inconsistent) to see if there was some sort of trend, some factor of relatedness that was common between bird species that have been observed head bobbing and those that don't, but there's no clear link. It's seemingly random. I found it odd, but interesting.

www.reinhold-necker.de/Head bobbing print.pdf

 

[Andre]

http://jeb.biologists.org/content/97/1/217.full.pdf about this phenomenon:

...One theory is based on the idea that movement in the environment is more easily detected if the eye is still (i.e. in hold phases) and that movement parallax (Gibson, 1950) generated when the eye is moving contributes a monocular depth perception (Welty, 1963). Thus head bobbing is considered to alternately optimize these two modes of visual exploration. This and the following theory emphasize monocular vision because many birds' eyes are laterally placed and thus they have only a monocular
view of much of their visual field.

Frost (1978) proposes that the thrust may provide retinal image motion in a preferred velocity range. The idea is that there are units in the visual system optimally responsive to stimuli in the velocity range provided by thrusts, and further, that the absence of backwards movement of the head keeps these units in an unadapted state.
The above theories are, of course, not mutually exclusive and the actual explanation may well involve a combination of them...

...There are two kinds of thrusts, those with and without saccades. It is difficult to sustain a theory involving visual input during thrusts with saccades. However, both Welty's and Frost's theories about the possible function of head bobbing may be correct for the thrusts without saccades.