General Distribution
Reported sightings of porcupines in southern California are rare. One historic occurrence was reported
from the San Bernardino Mountains in 1906 (Hall 1981). The most recent porcupine record is from a
road kill in the San Bernardino Mountains in the 1960s (Stephenson and Calcarone 1999). There is a
reliable report of a road kill in the San Gabriel Mountains during a large wildland fire in the 1980s (Loe
pers. comm.). Some evidence for porcupine presence in the San Bernardino Mountains was found in
1989. Stephenson (1999) reported that lodgepole pine trees in the upper end of Balky Horse Canyon in
the eastern San Bernardino Mountains were stripped of bark in a manner similar to that described in
previous reports of porcupine behavior (Dodge 1982). In addition, field crews conducting research on
California spotted owls have reported several sightings of porcupine during the 1990s (LaHaye pers.
comm.). Systematics
Hall (1981) recognized six subspecies of North American porcupine (Erethizon dorsatum), also known
as American porcupine (Woods 1973). The subspecies E. d. epixanthum occurs in northern and eastern
California (Woods 1973, Hall 1981). Porcupines in southern California were formally recognized as E.
d. epixanthum (Woods 1973) but were more recently identified by Hall (1981) as E. d. couesi, a
subspecies described from Arizona and Nevada. Habitat Requirements
In California, porcupines are primarily found in coniferous forests, but across western North America
they occur in a wide variety of habitats including pinyon-juniper woodlands, riparian forests, sagebrush,
rangelands, and desert chaparral (Dodge 1982, Woods 1973, Zeiner and others 1990). Reproduction
Porcupines usually breed during autumn or early winter. After a gestation period of about 7 months,
young are born in April, May, or June (Woods 1973). Females generally have one young; twins are
rare. Daily/Seasonal Activity
Porcupines are generally solitary but may occasionally share a den with other porcupines in the
winter. Porcupines are mostly nocturnal and are active year round except when temperatures fall below
0 ° F (-18 ° C) (Woods 1973).
Porcupines have been known to wander between different habitats and occasionally migrate short to
long distances (Woods 1973). Porcupine migrations have been reported in Oregon and northern
Montana. Diet and Foraging
Porcupines shift their foraging habits between winter and summer. During the winter, they feed
primarily on the inner bark of trees and on evergreen needles (Woods 1973). In the western portion of?their range, porcupines prefer to forage on yellow pine trees. In summer they feed on a variety of food
items, including roots, stems, leaves, berries, catkins, seeds, flowers, nuts, riparian vegetation, and grass
(Dodge 1982, Woods 1973). Territoriality/Home Range
Using radio-telemetry over a 30-day period, Woods (1973) determined the average summer home range
of porcupines to be 32 acres (13 hectares) for females and 36 acres (14.6 hectares) for males. The winter
range is smaller and more restrictive than the summer range. In New York, the winter feeding range of
porcupines was reported as 13.3 acres (5.4 hectares). Porcupines are not territorial, but have been
reported to defend their feeding trees (Woods 1973). Predator-Prey Relations
Fisher (Martes pennanti) is the primary predator of porcupines (Woods 1973). Managing fisher
populations has been suggested as an effective method of controlling porcupine numbers (Cook and
Hamilton 1957). Mountain lion, bobcat, red fox, coyote, bear, marten, wolverine, eagles, and great
horned owl have also been reported to prey on porcupines (Ingles 1965, Woods 1973). Literature Cited
Cook, D.B.; Hamilton, W.J., Jr. 1957. The forest, the fisher, and the porcupine. Journal of Forestry 55:
719-722.
Davis, W.B.; Schmidly, D.J. 1994. The mammals of Texas. Austin, TX: Texas Parks and Wildlife Press.
Dodge, W.E. 1982. Porcupine, Erethizon dorsatum. In: Chapman, J.A.; Feldhamer, G.A., eds. Wild
animals of North America. Baltimore, MD: Johns Hopkins University Press.
Hall, E.R. 1981. The mammals of North America. 2d ed. New York: John Wiley & Sons.
Ingles, L.G. 1965. Mammals of the Pacific states: California, Oregon, and Washington. Stanford,
CA: Stanford University Press.
Stephenson, J.R.; Calcarone, G.M. 1999. Southern California mountains and foothills assessment:
Habitat and species conservation issues. General Technical Report GTR-PSW-175. Albany, CA: Pacific
Southwest Research Station, Forest Service, U.S. Department of Agriculture.
Woods, C.A. 1973. Erethizon dorsatum. Mammalian Species 29: 1-6. Published by the American
Society of Mammalogists.
Zeiner, D.C.; Laudenslayer, W.F., Jr.; Meyer, K.E.; White, M., eds. 1990. California's wildlife. Volume
III: Mammals. California statewide wildlife habitat relationships system. Sacramento, CA: California
Department of Fish and Game.
Information gathered from California DFG - California Interagency Wildlife Task Group
