Porcupine Dens
In winter, porcupines, rather than build their own dens, seek out ready-made natural den sites, such as rock outcroppings, hollow logs and trees, even abandoned beaver lodges. Regardless of where they are, porcupine dens are often conspicuous because scat accumulates at the entry of the rock or log den where a porcupine is dwelling or at the base of an occupied tree (where it spills out from the den located several feet above the ground).
If you find a tree with a pile of scat at its base, and perhaps several paths leading to nearby food sources such as hemlock trees, look up to see if there is a cavity in the tree. Porcupines often return to the same den year after year; occasionally I have found that if a tree is being reused, whether by the same or a different individual, I’m not sure, porcupines often chew patches of bark off at or near the entrance to the opening of the den. One can only surmise that this is perhaps a visual signal to other porcupines and tree-dwelling creatures that the tree is currently claimed.
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