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Re: back to science




On Thu, 28 May 1998, Tony Canning wrote:

> I suspect you're at least partly right here - the need to guard the
> nest could restrict the number of eggs per clutch.  However, we have no
> idea how many clutches they could produce - it is possible that parental
> care ended at hatching at which point they would be free to lay another
> one.  If infant mortality were high (probable) they might have produced
> large numbers of young, but not in a single clutch.  I can't think of any
> other vertebrate with LESS energetic investment in a clutch of eggs than
> a large sauropod, and I doubt that energetics were a limiting factor.

This depends how encompassing the term "energetics" is.  A broad
definition might include: defending a nest; building a nest; fighting for
a nest site; courtship travails; defense costs; provisioning costs; and
finally, inasmuch as reproduction is the "purpose" of every organism, and
inasmuch as growing to a monstrous size was "for" putting new copies of
itself into the future gene pool, the very size of these animals was a
kind of energy expense.


And, in another post, the comment was made that cuckoos practice a lay and
leave strategy.  But this is only true from the parent's perspective.  The
eggs require parental attention--just parents of another species!  And I
would suspect that the bigger the animal the less likely such a strategy
was feasible.  Although it is known that turtles will lay their eggs in a
crocodile vegetation mound...so maybe not.