Foreign Finches gone Wild

[Mattyboy]

The older field guides to Australian birds note that feral flocks of Black Headed Mannikins were established for a while in reed beds near Sydney. That introduced species did not survive longterm. We don't know why.
The colonies of Red Bishops and White Winged Whydahs that once existed in SA and NSW respectively did well for a while but were apparently trapped out of existence, probably due to their scarcity in captivity and their monetary value.
Bullets were dodged in all these cases. We don't need more feral birds. We were quite lucky that more didn't become established when wild caught birds were being casually imported pre WW2.
Our present aviary populations of foreign finches are quasi domesticated and even in the event of a large scale release would have next to no chance of surviving and breeding.
St Helena (Common) Waxbills are now widely feral all over the world and spreading rapidly, even in southern Europe and parts of Asia. They're all over the Pacific islands. We're lucky they never got a toehold here back when that was possible, when wild birds were being imported.