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Re: mammal mystery



 

On Tue, 18 Feb 1997, Ronald Orenstein wrote:

> Once again Mr Bois is ignoring birds.  Rails are extremely good at creeping
> through tangled vegetation and they do NOT travel torso-first - there are
> many other examples.  The only birds I know of that habitually walk around
> torso-first are some water birds with their legs set so far back on their
> bodies that they have little choice (eg penguins) and the Plains-wanderer
> of Australia, a bird of open grasslands.  Let Mr Bois spend a few hours (as
> I have) trying to get a glimpse of a tapaculo in a Brazilian thicket and
> then tell me how impossible it is for bipeds to be skulking little
> creepers!  Even a fairly large rail (and some of the big ones probably bulk
> larger than some small dinos) can squeeze through some pretty tight spots.

Would that I could spend time in Brazilian thickets.  In the meantime I
note the relatively few species which live in thickets and are flightless
(as non-avian dinosaurs were).  The kiwi is an exception-and I needn't
explain its survival.  Rails are not flightless are they.  They can fly
away from a low to the ground predator.  Surely if they were as "good" as
the others in this niche they would lose their wings.  After all, it is
expensive to fly (I claim this is demonstrated by the apparent rapidity
with which flightlessness occurs on predatorless island species).
Further, I say that the four legs are better at getting through what must
be, in a tangled thicket, a series of hoops.  It means landing on your
feet instead of your beak.  Otherwise, how to explain the great lack of
bipeds (without wings, now, since wings provide means
of escape) in the tangled thickets?