The white heron is also known as the Great Egret. With defining features such as its yellow eye colouration continuing above the eye, a distinct kink in its neck, and long yellow/orange beak. Separating it from the more common relative, the intermediate egret in the wetlands.
These birds are common throughout most waterbodies in Australia, however, I just noticed the map on Wikipedia today does not include Australia in its distribution. We tend to be forgotten or unknown to most of the world though? Something odd there, but I did expect better from an Oxford publication in 2005.
In general, these birds migrate to breed and are a very common sight around waterways both salt and freshwater in Australia. Their beak is perfect for picking small fish right from the top of the water. Their behaviour is simple, they simply walk alongside the waterways with their long legs eating the unsuspecting fish.