This bird was originally known as the Ground (or Mountain) Thrush. More recently it has been called White’s Thrush, and now it is known as the Bassian Thrush (Zoothera lunulata). I mention all of these names, in case you wish to refer to any older Bird Books which you might have.
I have seen this bird in the Robertson Nature Reserve, usually late in the afternoon, which is a time of day when it seems to be quite active. The first time I saw it, two years ago, it walked ahead of me, along one of the paths. It was difficult to see in detail, but its shape and behaviour is distinctively "thrush-like" - a bird which runs along the ground, stops, looks around, and then runs again (like the much more common "Blackbird").
Recently I observed two Bassian Thrushes at the Robertson Cemetery, in the heavy brush, just at the end of the road leading to the Cemetery. They are a bird of the heavy cover. They search for worms and ground-dwelling insects, under the leaves on the ground. Consequently, it is likely that, as with the Whipbird, you will hear the bird searching through the leaves on the ground, looking for food, before you will see it appear under some vines or other low growing plants.
To observe these birds, I found it necessary to sit perfectly still, underneath a bush. I tried to photograph them, but with little success, as they are quite shy, and they like to come out to play, late in the afternoon, when the light is poor. (Sorry about the poor quality image.)
They are extremely well camouflaged. It is for this reason that this bird is easily overlooked. It is not a common bird, but it is not regarded as rare. From my experience, you could expect to find this bird in any local patch of heavy rainforest around Robertson. I have also heard it calling, just on dusk, in the dense scrub along the Belmore Falls Road, but I have not actually seen it there.
In its behaviour the Bassian Thrush is very similar to the introduced "Common Blackbird" - to which it is related. The call of the Bassian Thrush is a thin whistle, not dissimilar to the Blackbird. It is known to call at night, and at "first light", and at dusk.