From: andrewt@watson.ibm.com (Andrew Taylor)
Subject: Re: Population growth and cultural destruction (Re: Nast
Date: Wed, 30 Dec 1992 19:23:17 GMT
Disclaimer: This posting represents the poster's views, not necessarily those of IBM
Organization: IBM T.J. Watson Research Center

In article <725702732snx@tillage.DIALix.oz.au> gil@tillage.DIALix.oz.au (Gil Hardwick) writes:
>Please do cite just one occasion where I have insisted exclusively on
>graduate qualifications to post here?

   Message-ID: <724469845snx@tillage.DIALix.oz.au>
   >The *minimum* entry requirement should be graduate level, while the
   >rest get on with mastering the undergraduate basics. Or qualifying for
   >fresher entry to start with would help . . .

>The issue throughout has been on the standard of debate, expecting that
>people do at least some level of homework before engaging in reasoned and
>thoughtful argument on any matter concerning the environment.

But you don't do this.  For example, you posted that quolls are extinct.
Not only are there several extant species but one is found not far from where
you live. Your knowledge of Zimbabwe apparently doesn't even extend to its
location.  But when I point out your many errors, the response is another
20 lines of blather, unblemished by any knowledge of Zimbabwe.

>I am far more interested in your reasons for selecting this one among
>very many indeed, and reposting it now after no other response to it
>was forthcoming whatever.

Actually I responded at the time but our news machine apparently did not
transmit it.  Here is another response to you which was apparently also lost.

> I have mentioned here before that it is the very small species rapidly
> becoming extinct . . .

You claimed this here before about Australian mammals and I explained to you
why it wasn't true.  You responded saying you were ignoring me because I wasn't
an Australian citizen (I am). Let me try again.

Although there have been a few extinctions among Australia's small mammals,
mainly hopping-mice with small ranges,  they have been relatively unscathed.
It is largely medium-size mammals that have affected.  From memory the critical
size range is 0.5 to 10kg.

One theory is that rabbits overwhelmed and destroyed the drought refuges
that these mammals depended on.  Sufficent fragments remained to support the
small mammals and the large mammals did not depend on the refuges.  It is also
likely that mammals in this range were more vulnerable to fox predation.
Tim Flannery's Australia's Vanishing Mammals should discuss all this.

[In response to an example of an inverted biomass pyramid from Alan McGowen]
> Alan, you forgot the case of land reptiles (water pythons) which live
> off small land mammals (swamp plain rats) as their respective life-
> cycles replicate those of whales and krill, for example.

Last I heard, there wasn't a good estimate of the density of the Flood Plain Rat
(R. colletti)'s density. The indications are it is extremely abundant.
Do you have any reference/source/basis for the claim that the Water Python's
biomass exceeds its prey

> cold-blooded reptiles just hybernate on it without feeding for extended
> periods over years while populations of the former wax and wane.

Reptiles do not hibernate, they may become torpid. I doubt Water Pythons 
much of that either.  I doubt even more that they spend years without feeding.

> A high turnover, BTW, does not equate with high productivity,

How can a high turnover not correspond with a high productivity?
Surely the replacement of lost individuals requires high productivity at
least at the species level.

Andrew Taylor