Yowie wrote:

This problem of "imported" species out-doing the native species is a
major problem here in Australia, particularly when it comes to feral
cats, dogs and pigs, although there are many other introduced species
that are wreaking havoc in their own environmental niches (can toads,
european carp, indian mynah bird etc etc).

Aren't cats causing problems in the Galapagos islands, too? None of the
animals there have predators, so they didn't evolve any fear of other
animals. That's a big part of the charm of that area - the animals will
come right up to you because they have no reason not to. But with cats
on the island(s), many species will be in big trouble.

And then there's the brown snake in Guam.

Joyce