There are a few weeks in September and October when acorns (and beechnuts) are mature enough to eat, but haven’t yet fallen to the ground. Porcupines take advantage of this nutritious supply of food that is not yet accessible to small rodents, deer and turkeys, and climb oak trees to consume acorns. Because an average porcupine weighs between 12 and 35 pounds, it is unable to climb all the way out to the end of a branch, where acorns are located, so it nips off the tips of fruit-bearing branches and then scoops out the acorn, leaving the cap still attached to the branch (diagnostic porcupine sign). When all the acorns on a branch have been eaten, the branch is discarded. You can often find many of these branch tips, or “nip twigs,” in the canopy of large oaks on a good mast year, but inevitably some fall to the ground. The end of the twig is usually cut at a 45° angle, and often you can see the lines made by the porcupine’s incisors. (Beechnuts are also harvested in this manner, as are the cones and terminal buds of eastern hemlock in winter.) Red squirrels also nip twigs in order to reach fruit, but typically do so when they harvest the cones and terminal buds of conifers. (Thanks to Ethel & Michael Weinberger for photo opportunity)
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