Re: K-T Theories

[larrys@zk3.dec.com]

>Well, there are still rabbits in Australia, if that is what you mean.
>They are often eradicated *locally*, but they tend to return in
>the next population boom.

This was the scenario I was wondering about.  If the population
was in decline because of massive disease influx - more, probably
than just one disease, however virulent, could achieve - then how
much collateral damage needs to be inflicted to achieve extinction?
If Australia ever _does_ manage to eradicate the pest, we might
have an interesting data point to add the K-T argument, but it
seems fairly theoretical at this point.

>This whole thing is a fairly classic story of ecological imbalance.
>The rabbits were accidentally introduced into Australia (as pets?)
>and soon become the most common animal on the continent, due to
>a total lack of natural enemies and a nearly complete lack of any
>of the common diseases that kept the rabbits in check in their
>natural habitat.

Introduced as food.  I gather this was a fairly common occurance
with European settlers to toss out a few rabbits on new islands
so they will make a ready source of meat.  It was a devastating
practice, but they never noticed.  They did it all over the world,
but most places had predators that could deal with them.  I recall
reading that the thylacine was able to make a living off them, but,
of course, they were exterminated separately, partly, I suppose,
because they ate rabbits.  I don't think Australia had any other
large predators at that time.

regards,
Larry