Porcupine Sign
Typically, male porcupines spend days at a time up in eastern hemlocks, eating the tender buds and leaves of branches, while females tend to spend the day in a den, and head for nearby food at night. In the photograph, a porcupine den tree is on the left, with scat from the den having fallen on the snow below. The trail you see was made by the porcupine, as she went from her den tree to a nearby feeding tree. Usually a den is chosen within a short distance of food, as was this one. If you look closely at the uppermost quarter of the photograph, you will see a sign that indicates recent porcupine activity – nipped hemlock branches in the snow, that have been discarded by a porcupine, who’s feeding in the branches up above them. It’s much safer to remain on a large limb and pull the desired tip of a branch in to you than it is to attempt to climb out on a thin branch. Once the porcupine nips the tip of the branch off and eats the tender buds and leaves, it drops the branch to the ground below.
Naturally Curious with Mary Holland 
What Other Naturally Curious People Are Saying