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Re: Birds Came First question.




On Thu, 2 Jul 1998, Ronald Orenstein wrote:

> At 10:04 AM 02/07/98 -0400, you wrote:
> >
> >Birds are, with the exception of one (or two?) megapode species, united by
> >the following characteristics: intensive parental care during incubation;
> >nest siting in the open air (where parental care is necessitated--unlike
> >fossorial nests).
> 
> This is not true.  First of all, there are more than two species of megapodes
> (22 according to the latest monograph).  

Yes, but only a fraction of these are hole-nesters--I think this is the
term I should have used rather than "fossorial".  I realize the birds you
listed are fossorial but they all (don't they?) manipulate the nest during
incubation.

> The function of parental care is far more than nest protection, of course -
> and in fact at least some megapodes (particularly the mallee fowl) are
> in almost constant attendance on the nest mound; parental care ends only
> when the young leave the nest.

In fact megapodes are unique in that they don't do _anything_ for
hatchlings.  Post-hatchling care is, I believe, a uniting trait of all
other birds.  And Coombs (in _Modern analogs for dinosaur nesting and
parental behavior_) argues that such hatchling independence and the long
incubation and predator-friendly vegetation mounds "necessitates nearly
total freedom from egg predation." 

> So I do not think Mr. Bois' generalization is meaningful.

Out of some 9000 species of birds only 4 or so have become secondarily
turtle-like in their reproductive behavior (inasmuch as they dig, bury,
and leave their eggs).  It seems fair to generalize.  Sorry I got my terms
wrong.