Koala researchers in the Brisbane Ranges have discovered that they can identify individual koalas by the pattern of dots on the nose. This last weekend we went down to our farm at Heywood, and discovered a noisy male koala in a tree near the house. Next day he had gone from the tree but then we found another one nearby. By comparing photos I think I can say with confidence that it's the same individual because his nose pattern is identical.
Koalas can be very noisy. Several times I have been wandering in the bush, alone, watching for birds or flowers, jumpy about the possibility of stepping on a snake, wary of leeches climbing my boots, and nearly jumped out of said boots when a, previously unseen, koala has bellowed immediately above my head. They are very very loud. My immediate thought always is that somehow the neighbour's bull has crept up behind me. The Australian bush has nothing in the way of ferocious non-vegetarian mammals to be scared of so this reaction must be built into me/us genetically from the hunter-gatherer days of our ancestors in Africa.