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From: afsipmh@cid.aes.doe.CA (Patrick Hertel)
Newsgroups: rec.birds,sci.bio
Subject: Re: HEAD JERKING OF WALKING BIRD
Message-ID: <1990Jul30.132412.6397@cid.aes.doe.CA>
Date: 30 Jul 90 13:24:12 GMT
References: <1990Jul28.033019.5059@ddsw1.MCS.COM>
Reply-To: afsipmh@cid.aes.doe.CA (Patrick Hertel)
Organization: Environment Canada
Lines: 16

In article <1990Jul28.033019.5059@ddsw1.MCS.COM> arf@ddsw1.MCS.COM (Jack Schmidling) writes:
>
> 
> Subject: Re: HEAD JERKING OF WALKING BIRDS
> 
> 

 I believe that the head jerking is due to the fact that a bird's eye is 
fixed and therefore it has to move its head to "refresh" its receptors.
It would explain why the head jerk is not necessary when the bird is carried 
and looking off to the side.
-- 
Pat Hertel                 Canadian Meteorological Centre
Analyst/Programmer         2121 N. Service Rd.
phertel@cmc.aes.doe.ca     Dorval,Quebec
Environment Canada         CANADA           H9P1J3