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Re: parental care (cobra)

On 12/22/03 5:10 AM, "Thomas de Wilde" <jedimr_thomas@hotmail.com> wrote:

> Jonathan Schmidt replied me (offlist):
>> What about the nest guarding in komodo dragons?  The
>> films I've seen certainly seem to show pretty plainly
>> that they guard their nests.
>> I would also point out that some kinds of turtles
>> prefer to lay their eggs in alligator nests due to the
>> regulated temperature and the guardian female.  It
>> isn't exactly parental care but is more than most
>> turtles do.

> I'm not the one who quoted that of all squamates only king cobra is
> documented to show true parental care, nevertheless I have only seen this in
> his (or better her) royal highness though. But I won't denie that there are
> other squamates or tortoises who show parental care

I'm the one who made the original comment.  As far as I know, komodo dragons
have not been shown conclusively to care for offspring or nests.  However,
there may very well be a publication on the subject that I missed.
Similarly, there is some evidence from zoo collections (including one in
which I worked for some time) that Solomon Islands skinks show maternal care
of the offspring.  This is, however, not much more than a hunch based on
circumstantial evidence at present.  Again, site choice is well documented,
but actual nest guarding or neonate protection is unknown for the huge
majority of squamates.

Incidentally, pythons that help incubate eggs also offer them some degree of
protection, so that's another marginal case.

>> importantly, we know some dinosaurs made nests that
>> even if covered in vegetation were relatively exposed
>> as mounds.  Is there any animal in existence that
>> builds an exposed nest and doesn't guard it?

Do megapodes guard?  The chicks are superprecocial, after all.

>> We may not want to say parental care is proven beyond
>> a shadow of a doubt in dinosaurs but is there any real
>> reason to think they wouldn't care for their young or
>> any reason to not say they more than likely did?

Given that crocs and birds show care, and given the data on nest
construction, it is reasonable to argue at least some species showed nest
guarding.  My comments about squamates being non-protectors was mostly just
in response to another list comment that terrestrial verts overwhelmingly
show parental care.

Also keep in mind, as was mentioned a few times on this thread, that there
are several levels of 'care'.  There is nest site selection, nest building,
nest guarding, protection of neonates, etc.  Even if dinosaurs showed care
(and again, many likely did), the level of care is another issue entirely.

--Mike Habib