I've noticed numerous fresh small digging holes over winter and early spring on Majura reserve. Conical shaped holes 5-10cm deep. Not like rabbit digs.
Could they be echidnas getting grubs?
Pigs do a remarkable variety of marks and diggings but this is not one I have seen from pigs and pigs are not known at Ainslie Majura at the present time. Long nosed bandicoots are spreading in the ACT and they do what you describe - numerous small holes, conical shaped 5-10 cm deep but not the same as rabbit digs. Echidnas and bandicoots overlap in what they produce - either can produce some of the digs produced by the other, but only echidnas can produce wide digs, move stones more than a few cm wide, and throw dirt well to the side. I think this is robust enough to be echidna, most likely.
Bandicoots have been eliminated from Mts Majura Ainslie a long time ago, I'm afraid. There were pigs at the north slope attracted by carcass; perhaps 10years ago.