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Re: Troodon again



John Bois wrote:
> 
> On Tue, 23 Sep 1997, Dann Pigdon wrote:
> >
> >       Tool use is not necessarily signs of high intelligence. There
> > are many birds that use tools. I recently saw footage of a
> > wedge-tailed eagle using a stone to crack open an emu egg, and as
> 
> Could you tell us how the eagle did this? Thrown, like an Egyptian vulture
> at an ostrich egg; dropped from a great height, or held in the beak and
> hammered.  Was it a rockish stone, or merely a pebblish stone?

        It was a largish pebble, something it could fit in its
beak but which would be large enough to cause damage if it was
thrown at your head. Remember that the wedge-tailed eagle is the
largest raptor in Australia, so they have fairly large beaks.
The eagle held it in its beak and repeatedly belted the emu egg. Many
raptors seem capable of this, especially when it comes to eggs.
        A species of black cockatoo will also break off a piece
of branch and beat it against the trunk of a tree to attract a
mate. There is a snail eating species (I can't remember where or
what its name is) that uses a regular anvil stone to crack open
a certain species of snail. These stones are a boon to people who
study snails, since the whole range of morphological variation
of the snail species in the area is gathered and left around
the anvil. Tool use amongst birds may be as common as it is
amongst primates, since the majority of primate species never use
tools at all.
        What does this tell us about dinosaurs? Probably not much.
All modern birds seem decended from flying anscestors, so the various
weight saving features seem to have robbed them of many a useful
dinosaurian trait (sharp teeth, large heads with strong jaw muscles,
clawed hands, considerable bulk). Perhaps some modern birds have
to resort to behavioural adaptations to get things done that many
dinosaur species could have accomplished physically. Does this
sound familiar, as in the world's top predator that lacks claws,
sharp teeth or carnassials, great strength and speed, sharp senses?
(ie, us).
-- 
____________________________________________________
        Dann Pigdon
        Melbourne, Australia

        http://www.geocities.com/capecanaveral/4459/
        http://www.alphalink.com.au/~dannj
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