Hello!
Last year I had a solitary Heron (a white faced heron I think) move into my yard for a few weeks, hanging around the pond. It looks like he has come back again, but this year he is very vocal. He has been here for about one week now, but he is still the only heron I've spotted. Are they common in the Toowoomba area?
I had the same for years, the same White-faced Heron came every year, sat in a tree or on a fence and called out very loud.He also kept looking to the sky, as if waiting for a partner. After a few days he left. The former owners of our property told me that a pair had a nest in our tree for many years. I think he was waiting for the mate to turn up, but as that didn't happen , left.
Hard to say though, because both sexes look similar, you might not be seeing the same bird?
M-L