Following on my return to Aus and checking out these messages and noting my
prior writings to birding aus (if not COG-list) about rhynchokinesis (see
information below). I believed that ducks cannot do this and was going to
add this comment to these about the Shoveler. Although as it turns out, it
wasn't that, in the subject photo, but just the bird's wing tip lined up
with the head.
However I have attached photographic evidence that ducklings can do this
rhynchokinesis, to add to the debate. I will admit that this photograph
attached here is pretty much the pinnacle of my bird photography ability. If
you look closely at each duckling, in some the bird's beak is properly
closed but in others the tips are spread. Now if you don't believe this is
my original work and I am indulging in a breach of copyright, then I
apologise, because I do not know who to ask and wonder if anyone else
does.......
Philip
Hi All,
For those interested in this. Between three pieces of information, all of
which match but take different approaches, we have a full story. It is clear
that there are two types of cranial kinesis (which is the term I used for
both): rhynchokinesis as in this case and, the other being prokinesis (the
common form). I'd say it must be that the same mechanism that applies, the
difference being the point of flexure in the beak and the point of
attachment of the quatratojugal to the premaxilla. It sounds complex but
actually it is easy to demonstrate on a bird's skull.
Philip
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