This was in the outback (not in a zoo) of Mareeba, and this particular guy appeared to be the grizzled, dominant male of the mob of wallabies that lived in the area. He is a Mareeba rock wallaby, and he and his group actually came right up to my bio group (although he would bite and chase off any that got too close to him).

Annnnd I thought he looked to be contemplating something under that nice tree, so I dubbed this photo "The Thinking Tree".