Another interesting note about "a" megapode, although I don't know if
it applies to other members of the family. Brush Turkey chicks hatch
fully fledged! I though that was pretty amazing. They're able to fly
hours after hatching as an adaption to having no parental care (I
assume it's an adaption - although which came first, the lousy parents
or the independent children? ;^)
Regards,
Chris - Brisbane
On Thu, 14 Oct 2004 11:38:44 +1000,
<> wrote:
>
> Hugo wrote "Evolution of the use of external heat sources for incubation
> must have included adaptations to egg/embryo physiology. Inadvertent turning
> may occur in the course of mound maintenance, but is not only unnecessary
> but also potentially damaging as megapode eggs have shells that are
> considerably thinner and more fragile than would be expected from comparison
> with those of other birds."
>
> I doubted whether megapodes would turn their eggs deliberately (as Hugo also
> said "To what extent are megapodes 'aware' of their eggs, anyway?"). Egg
> shells are very thin (apparently 69% that of the expected shell thickness)
> so any disturbance is likely to be dangerous to the well-being of the egg.
>
> Internal egg morphology does apparently differ from that of other eggs with
> the proportion of yolk to albumen very different. It could well be that
> these eggs have adaptations to counter the problems associated with simply
> just "sitting in the dirt" waiting to hatch.
>
> Isn't nature wonderful. Anyway, it was just one of these questions that
> sometimes pops into one's head!
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