If you're interested in the state of Australian bird life there are a number of reports available from Birds Australia, including the latest one on the effects of invasive species.
The report (a large download by the way and in a format that's a bit hard to read on a small screen) suggests that some native species are doing quite well, possibly too well (eg Australian white ibis) in some areas and others not so in other areas, for a number of complex reasons. But suffice to say that introduced plant species, as well as ferals (cats, foxes, etc) and many other invasive human factors, have upset the balance. This is no surprise in general but the details are worth reading.
The most common birds I see around my home include the noisy miner (introduced), spotted turtle dove/pigeon (introduced), blackbirds (introduced), pied currawongs, magpies, lorrikeets and Australian ravens (or crows as most people call them) plus silver-eyes and New Holland honeyeaters. The point is, are the natives in this list the ones that would normally have been seen around here a couple of hundred years ago, let alone 20, 50 or 90 years ago?