> Hi to Everyone,
> Could anyone shed some light on the reason for the behaviour of the
> Australian Hobby as described to me by Chris Hassell the warden at the
> Broome Bird Observatory.
>
> Chris says:
> At 5pm on 29th July 1997, five hundred metres along the road to Willie
> Creek off the Cape Leveque road on the Dampier Peninsula, four of us
> witnessed an Australian Hobby (Falco longipennis) eating dirt, small stones
> and charred wood fragments.
> [snip]
>From http://numbat.murdoch.edu.au/Anatomy/avian/avian4.html:
The gizzard is a highly muscular structure lined with a tough, abrasive
keratin-like layer of koilin, known as the cutica gastrica. It shows great
variation, and is most elaborate in granivorous and herbivorous birds.
The sandpaper-like grinding action may be assisted by grit and stones
deliberately ingested. This action is enormously powerful and can even deal
with metal particles.
I remember reading about this in "The Dinosaur Heresies" by Robert Bakker;
some dinosaur fossils have been found with neat piles of polished stones
nearby, suggesting that dinosaurs also had a gizzard (as do crocodiles?)
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Paul Taylor
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