Porcupines are slow moving nocturnal wild animals. Home owners may have two concerns regarding porcupines in their yard; one being that the porcupines are eating their trees, the other being the risk of injury to their pets as the result of being stuck with quills.
It should be noted that dogs are more likely to become stuck with a face full of porcupine quills than are cats. A dog will try to attack, where as a cat will usually back off. Porcupines cannot throw quills but may leave several stuck in a tree as a result of climbing – cats will sometimes become stuck with them this way.
Other than actually seeing the porcupine, or having your dog be stuck by one, you may notice areas on your trees that are stripped of bark. If you go out at night you may hear a porcupine in your tree. To note that is how I first became aware of these critters in my own yard, hearing noises in the apple tree at night.
As mentioned porcupines are nocturnal so the best time to see one in your yard is after dark, however in the day they often rest, sleeping in a tree. Depending on the amount of foliage in your tree you might be able to see one sleeping, they tend to return to the same tree day after day.
There are several things you can do to get rid of a porcupine.
In my case, where the porcupine was in an apple tree, I simply went out for a few nights and harassed it, eventually it never returned. I took a broom and poked at it until it came down from the tree, at which time I chased it away. They are slow moving so fairly easy to chase. I tried to get outside before it showed up so that I could chase it before it got into the tree. On one occasion it managed to climb higher in the tree so I could not get it, but I went inside for a few minutes and it climbed down and left in that time. Thus we see that it is possible to “train” a porcupine to stay out of your yard, and trees.
You can also set up barriers around your trees. There are several products one can buy, often at landscaping stores, hardware stores, or even livestock supply stores, to keep porcupines out of trees. Even wrapping the tree with tin foil may help keep a porcupine out of the tree, but it should be wrapped to at least 4 feet. You can try making a barrier with chicken wire will work, but if wrapped too close to the tree they will simply climb the tree through the wire. Stucco wire fences work well, and should be at least 6 inches from the truck, and at least 40 inches tall.
Wooden fences around trees are useless as porcupines can climb them, or will chew on them.