I thought another hiker was approaching but the tooter turned out to be a porcupine. It waddled up the path to within about five feet of me before it noticed my presence. Undeterred, it simply paused briefly to look me over, made a slight detour around where I sat and continued up the trail, still tootling merrily. That night I heard that same sound around the lean-to where I camped. Fortunately my pack was safely hung from a nearby tree.
Porcupines are very interesting animals.
Those distinctive quills are modified hairs that stiffen within an hour of the animal's birth. Their feet and claws are well adapted to climbing and their winter food is the inner bark of trees. They often girdle the tree and kill it in the process of feeding, but woodlot damage is generally slight. Unfortunately porcupines also love salt and they chew on items like chairs and canoe paddles that are salt-coated from human sweat. For this reason many woodland cottagers have little affection for these beasts.