San Diego Desert Woodrat (Neotoma lepida intermedia)

San Diego Desert Woodrat (Neotoma lepida intermedia)



General Distribution
The desert woodrat is found throughout central and southern California and in the Great Basin, Mojave, and Colorado Deserts of Oregon, Idaho, Colorado, Arizona, and Nevada (Hall 1981). The San Diego desert woodrat occurs in coastal California from San Luis Obispo south through the Transverse and Peninsular Ranges into Baja California. Historic locations of the San Diego desert woodrat on and adjacent to National Forest System lands have been recorded from San Luis Obispo near Los Padres National Forest, San Fernando near Angeles National Forest, Redlands and the San Bernardino Mountains on and near the San Bernardino National Forest, and Julian near the Cleveland National Forest.
Systematics
Hall (1981) recognized 31 subspecies of desert woodrat (Neotoma lepida) from the western United States and Mexico. Four subspecies, N. l. lepida, N. l. gilva, N. l. grinnelli, and San Diego desert woodrat, occur in southern California. Two additional subspecies, N. l. californica and N. l. petricola, are also found in the Monterey Bay area.
Habitat Requirements
Desert woodrats commonly inhabit Joshua tree woodlands, pinyon-juniper woodlands, mixed chaparral, sagebrush, and desert habitats (Zeiner and others 1990). In the Little San Bernardino Mountains, desert woodrats occupy sandy deserts and boulder outcrops (Thompson 1982). Vegetation in these areas consists primarily of Joshua tree woodland and creosote scrub. Thompson (1982) observed desert woodrats actively avoiding open areas that did not provide adequate refuge sites. In rocky outcrops, desert woodrats are known to construct dens in the cracks between boulders using sticks, yucca leaves, tin cans, and other assorted materials (Thompson 1982). Desert woodrats appear to preferentially occupy dens in habitats with large-sized rocks and boulders because they provide better predator protection (Smith 1995).
Reproduction
In general, desert woodrats breed from late October or November through April, and females can produce up to four litters of two to four young each year (Bleich and Schwartz 1975). The gestation period is 30–36 days (Zeiner and others 1990).
Daily/Seasonal Activity
Desert woodrats exhibit nocturnal foraging behavior; any diurnal activity is restricted to the den site (Thompson 1982).
Diet and Foraging
Desert woodrats are primarily herbivorous and rely on a continuous supply of green vegetation for food and water (Thompson 1982). They do not appear to be highly selective in the type of vegetation they eat, but may be particular about the parts of each plant species they consume. Thompson (1982) observed woodrats eating the stems and twigs of one plant while discarding the leaves and flowers. Desert woodrats do not need to drink water. They are largely dependent upon succulent vegetation such as cactus and agave for moisture, although they can be sustained on creosote year-round (Lee 1963, MacMillen 1964).
Territoriality/Home Range
Thompson (1982) reported the average home range of desert woodrats in the Little San Bernardino Mountains to be 0.13 acre (533 square meters). Individual home ranges generally include one diurnal den and several feeding sites (Thompson 1982).
Predator-Prey Relations
Common predators of desert woodrats are snakes, owls, coyotes, badgers, skunks, and ringtails (Smith 1995).
Literature Cited
Bleich, V.C.; Schwartz, O.A. 1975. Observations on the home range of the desert woodrat. Journal of Mammalogy 56: 518–519.
Hall, E.R. 1981. The mammals of North America. 2d ed. New York: John Wiley & Sons.
Lee, A.K. 1963. The adaptations to arid environments in woodrats of the genus Neotoma. Univ. Calif. Publ. Zool. 64: 57-96.
MacMillen, R.E. 1964. Population, ecology, water relations, and social behavior of a southern California semidesert rodent fauna. Univ. Calif. Publ. Zool. 71: 1-59.
Smith, F.A. 1995. Den characteristics and survivorship of woodrats (Neotoma lepida) in the eastern Mohave Desert. Southwestern Naturalist 40(4): 366–372.
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.
Thompson, S.D. 1982. Spatial utilization and foraging behavior of the desert woodrat, Neotoma lepida lepida. Journal of Mammalogy 63(4): 570–581.
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