Last week, I asked if anyone could tell me what happened to this bur oak tree (Quercus macrocarpa) to lose much of its bark. There’s many reasons why a tree could lose its bark, so I tried to hint that I was “hiding” something in the provided pictures. What was I covering up? A North American Porcupine (. Congrats to @ttweakk on twitter for the correct guess!
This porcupine must have hung out in this tree all winter long by the looks of how much bark is missing. North American porcupines are generalist herbivores with a fairly variable diet. In winter, tree bark often becomes a primary food source, and porcupines can feed heavily enough from a single tree to the point of killing it. Because of the damage they can cause to trees, many people view porcupines as pests. But if this tree does die, it will create an opening that other trees can grow up in, contributing to a more varied and multi-layered forest.
Near the tree, I also found what appeared to be the porcupine’s den under a fallen log.
Porcupine pellets (poop) abounded inside.
Looking around the area, I didn’t see any other trees that seemed overly tasty to the porcupine. I wonder if the oak will produce any leaves in the spring. I think it might be a goner. I’ll have to check back and give an update. Maybe I’ll be able to give an update on the porcupine too. I consider myself as an expert porcupine spotter now (even though this is the first living, wild porcupine I’ve ever seen, yay!). You may notice the photos of the porcupine were taken in two different trees. I came back a few days later and still found the porcupine, which had moved to a tree a few hundred feet away that had no bark missing. However, a porcupine can have a 35 acre summer home range in Minnesota, so it might be tricky to find when more food is available.