It's interesting to see that some populations which are nearly wiped out due to habitat changes, can adapt to the new conditions and slowly rebuild ... but it leaves questions like if the adaptation was behavioural or physical which allowed it's survival is the bird that survived tending to be its own sub species of what existed.

In Australia, well the north part of Queensland at the very least, since the 80s there's really not been that much funding or an obvious program of population monitoring of whatever native species remain, including birds.

I miss what used to be common bird calls from my youth even though I didn't know which bird species was responsible. I've resolved the mystery for a couple I could recall but one still eludes me. In my parts the high canopy tropical forests have taken a huge toll from the 90s, no real wet season with warm rain, no large storms, (these days it's not uncommon to hear alarm around a storm dropping 3 inches in a couple of hours ... used to have years where they were not uncommon,) a fungus pathogen taking out some trees which may just be down to the trees being stressed more than their evolution allowed for - oh yes, the fact that many summer storms on their westerly approach had started to hesitate on a direct track over the coastal areas might just boil down to the man made heat bubble with open cut coal mining and the large areas as per mining which now have no to little vegetation.