Such extensive workings were found along the Wonderland Trail in Stevens Canyon in 1947 and 1948. The first indication of the activity of mountain beavers was the undermined condition of the trail in several places, where burrows crossed under the path and caved beneath the feet. Upon investigation many freshly cut stems of bracken were discovered, and several piles of recently excavated earth, in some instances sufficient to fill a bushel basket. This site was typical: excellent cover; several small streams; and deep, very moist soil with few rocks and an abundance of food plants.
Natural enemies of aplodontia undoubtedly include nearly all of the predatory animals, particularly the skunks and weasels, which can invade the dens without difficulty.
YELLOW-HAIRED PORCUPINE
Erethizon dorsatum epixanthum Brandt
The porcupine is a large, short-legged rodent (total length about 30 inches), clumsy and awkward appearing, slow-moving, bearing long, sharp quills or spines over most of the body and on the short, club-like tail. The pelage is composed of soft, brownish-black or black hair. Intermixed with the pelage, and extending beyond it are the quills and long, stiff, shiny, yellowish-tipped hairs, which give a yellow tinge to the underlying dark color. It is impossible to confuse this unique animal with any other found in the park.
The almost impregnable armor of the porcupine is adequate protection against most predators.
Specimens in park collection: RNP-42, RNP-47, and a mounted specimen, Longmire Museum, Park Headquarters.
The several species of porcupine are widely distributed, ranging in the timbered regions of the northeastern states, the Rocky Mountains from near the Mexican boundary northward, and from northern California into Canada and Alaska.
Formerly rare, the first actual record was of a single individual in Paradise Valley in 1933, porcupines are increasing throughout the forested areas of the park, although the animal is still considered uncommon.
An apparent lack of interest or concern in events is probably the outstanding characteristic of the porcupine. Protected as it is with an almost impregnable defense of quills, it has no need for speed and shows little fear of any other creature, even man. If pursued when encountered, it will waddle away at top speed, which is about equal to a man’s brisk walk. If crowded closely, the animal will take to the nearest tree if given the opportunity, or may thrust its head beneath a convenient root, log, or rock, then thrash the muscular tail about vigorously in an effort to discourage attack. The tail is indeed a formidable weapon. The quills are loosely attached to the skin, and are readily detached when they strike any object. They may even be loosened by the swinging of the tail, and fly through the air for a short distance. It is conceivable that quills thus detached might actually penetrate the skin at short range, but a porcupine can not “shoot” its quills.