North Country explorer from Amherst, New York
Habitat: Lowland, young mixed-wood forest.
These patterns in this softwood tree were almost definitely caused by a hungry porcupine, which we discovered nesting in its lair a few feet away. Rodents like porcupine and beaver love softwood trees like hemlock for their delicious wood below the bark. What is being nibbled at in this picture is the cambium layer of the tree, which is the area of new growth that is packed with nutrients, in order to make more vascular xylem and phloem every year. Porcupine have large incisors so they can effectively get at and remove the cambium.
I think this photo is a good testament as to how much work it is to rely on mature trees as a source of food. Each one of these minute scratches is part of a much bigger picture of repetition, time and energy expended by the porcupine. There are also some remarkable patterns created by this wild form of feeding.