[monocle]

Rabbits in Australia? Isn't this generally the case with imported species multiplying out of control because of the absence on natural predators?

[carptracker]

The conditions have to be just right for an invasive species to take off and become prominent. In general, very adaptable species do the best. And sometimes (the Perna perna mussel invasion of the Gulf Coast is the best example I know) an invasive species takes off and reaches huge abundances, and then later the native species figure out how to deal with the newcomers and then the newcomers can be driven down to manageable levels or in some cases they completely dissappear. Then there are other cases, like the rabbits, in which the oldtimers never learn to deal with the newcomers. In the case of Australia, most of the mammals are marsupials, which is a strike against them competitively to begin with, I think. Note that kangaroos and wallabys are not taking over anywhere new.