Characteristics of Porcupine, Erethizon dorsatum , Winter Den-sites in Living Trees in Wisconsin

Although Porcupines ( Erethizon dorsatum ) denned in a variety of structures in Sandhill Wildlife Area, Wood County, Wisconsin, hollow living trees predominated (67 percent). Diameter at breast height of den trees was significantly greater than that of trees in the surrounding forest, and den openings in living hollow trees were nearly twice the circumference of Porcupines. Porcupines probably do not prefer certain tree species over others; rather, they select species more prone to heart rot with cavities large enough to house a Porcupine.