This is the alpine form of Pseudemoia entrecasteauxii. As soon as you get above the treeline the normally plain brown colour pattern switches over a short distance (tens of metres) to this strongly striped form (not to be confused with P. pagenstecheri). It lacks some of the additional pale stripes on the back that are found in P. pagenstecheri. They look very different but a genetic study by Mark Hutchinson and Stephen Donellan indicated they were the same species. WillO.