Mammal Species of the World
Click here for The American Society of Mammalogists species account
- Original description: Baird, S.F., 1857 . Mammals. In Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean. Vol. 8, Pt. 1, p. 495. Beverly Tucker Printer, Washington, D.C., 8(1):1-757.
occurs (regularly, as a native taxon) in multiple nations
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: Extreme western North America, from the Columbia River in western Oregon south through California to northern Baja California, Mexico.
The range of the dusky-footed wood rat is restricted to the Pacific coastal area of the United States and Lower California. The range specifically extends from the Columbia River in Washington southward through the Sierra San Pedro Martir of northern Lower California. Toward the east, the dusky-footed wood rat's range reaches the Cascade-Sierra Nevada mountain system and the Mojave and Colorado deserts. In terms of altitude, this species lives at elevations of around 9,000 feet in the southern areas of its range.
Biogeographic Regions: nearctic (Native )
The fundamental pelage color of dusky-footed wood rats is cinnamon with variations toward tints of buff and pink. Every dusky-footed wood rat has vibrissae (whiskers) that are disposed in six parallel, evenly spaced rows. The ears are thin, large, rounded, and broad as well as hairy. The claws are short, sharp, curved sharply downward and almost equal in length. The claws are also colorless. There is some sexual dimorphism in this species. Females are about 38.5cm in length (including the 18.7cm tail). Males are about 44.3cm (including a 21.5cm tail). Males usually also weigh more than females.
Range mass: 230 to 300 g.
Average mass: 275.50 g.
Length: 48 cm
Weight: 267 grams
Comments: Heavy chaparral; hardwood, conifer, and mixed forests, typically in densely wooded areas with heavy undergrowth; riparian woodlands. Builds house of debris on ground or in tree; houses tend to be in situations that are shaded, relatively cool, and in good cover, and they may be used by many generations over several years. After breeding, males live in tree dens apart from females.
Habitat and Ecology
One study found that each woodrat averaged 1.8 houses/home range. Loosely colonial, with partially overlapping home ranges; several individuals may live in the same area, though individuals (aside from females with young) typically live in separate houses. Adult home range averages around 2,000sqm. Predators include hawks, owls, bobcat, coyote, long-tailed weasel, etc. Stick houses provide cover for many vertebrate and invertebrate commensals.
Most young are born from February (especially in south) to May. Gestation lasts 30-37 days. Usually one litter per year. Litter size is 1-4, usually 2-3. Weaning begins at three weeks (Carraway and B. J. Verts. 1991, Maser et al. 1981). Diet includes a wide variety of plants. Feeds on seeds, nuts, acorns, fruits, green vegetation, inner bark, and fungi. This woodrat stores food. It is primarily nocturnal.
The dusky-footed wood rat, although found on hillsides, usually select valleys and lives very close to small streams and water. Since this species likes areas that are covered, they tend to avoid open grassland and open oak woods with small amounts of underbrush. The plant species in the area affect the wood rat through the nature of the cover and screening it offers. Plants such as Arroyo Willow, Red Willow, and Coast Live Oak provide good protection.
Besides the biotic features of a habitat, there are also abiotic features which contribute to the nature of the dusky-footed wood rats' habitat. Light is avoided even when it is as weak as moonlight. Cold air is more suitable than extreme heat. When temperatures approach one hundred degrees fahrenheit, wood rats move to cooler places. Dryness of a wood rat's coat is important for maintaining good health, but low humidity is unfavorable. Within their habitats, rats live in colonies of three to fifteen or more nests (homes).
Terrestrial Biomes: chaparral ; forest
Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
Comments: Eats a wide variety of plants. Feeds on seeds, nuts, acorns, fruits, green vegetation, inner bark, and fungi. Stores food.
The dusky-footed wood rat feeds on seventy-two different types of plants. Some of these include Blackberry, Maul Oak, Valley Oak, Soap plant, Gold fern, and Bracken. This was determined by analyzing food specimens in homes of dusky-tailed wood rats. The plants consumed by the dusky-footed wood rat are utilized for nutrients as well as their water content. This species derives moisture from eating the vegetation. However, the availibility of certain plants varies with the seasons. This species has a tendency to store a large amount of food in its nests. In one nest, for example, there were one hundred and thirty-two cuttings of fresh material. The dusky-tailed wood rat eats food throughout the night. In one feeding period, they consumed 44.2g on average.
Population density is up to about 45/ha in optimal conditions; more typically 1-3 dozen/ha. One study found that each woodrat averaged 1.8 houses/home range. Loosely colonial, with partially overlapping home ranges; several individuals may live in the same area, though individuals (aside from females with young) typically live in separate houses. Adult home range averages around 2000 sq m. Predators include hawks, owls, bobcat, coyote, long-tailed weasel, etc. Stick houses provide cover for many vertebrate and invertebrate commensals.
Life History and Behavior
Comments: Primarily nocturnal.
Most young are born from February (especially in south) to May. Gestation lasts 30-37 days. Usually 1 litter/year. Litter size is 1-4, usually 2-3. Weaning begins at 3 weeks (Carraway and B. J. Verts. 1991, Maser et al. 1981).
Reproduction by a male dusky-footed wood rat depends on its proximity to other male conspecifics. In the presence of many male rats, individual male rats may not reach full sexual maturity or physical size. However, when a male wood rat is isolated it immediately increases its weight and becomes sexually mature. At this time, the testes increase in size dramatically.
The reproductive period of this species usually begins in late September and continues until mid-June or mid-July. This coincides with the onset of the rainy season and the growth of plants. The inactive reproductive period arrives in the dry season when much of the vegetation is not growing.
Females also show seasonal changes in reproductive activity. The months of April and May are when most females are reproductively active. Females mate with a single male, and there is no evidence of polygamy. During the breeding season, males move about changing nests in search of sexually receptive females. Males pair with the most accessible female, which is usually the one closest to their nests. The fewer females present in an area, the more a male will move.
Females remain in their original nests and may raise a succession of litters. Some females may experience reoccuring oestrous cycles without becoming pregnant. This occurs when there are fewer males than females in an area, and each of these males limits its attention to a single female. The result is that some females are without a male for a long time.
Once gestation begins, the female is intolerant toward the male and somtimes will attack the male. If a male approaches an intolerant female, and if he has not mated yet, he will leave the vicinity and find another receptive female. Once a male mates, he lives alone in a separate nest which he builds himself. By spring, most females begin producing young. The suckling young, about 2.8 per litter, are dependent to the mother until the time of weaning. Weaning begins three weeks after the young are born. After weaning, the young begin to eat the same greens as their parents. Females protect suckling young by hovering over them and attempting to bite an animal who tries to touch them.
Molecular Biology and Genetics
Statistics of barcoding coverage: Neotoma fuscipes
Public Records: 0
Specimens with Barcodes: 2
Species With Barcodes: 1
National NatureServe Conservation Status
Rounded National Status Rank: N5 - Secure
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
IUCN Red List Assessment
Red List Category
Red List Criteria
This species can be found abundantly within its geographgic range. It is not endangered or threatened.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
Comments: Generally populations are negatively affected by removal of undergrowth or shrubby vegetation.
Relevance to Humans and Ecosystems
Economic Importance for Humans: Positive
In coastal areas of California, feces from the dusky-footed wood rat can be found in large quantities in the inner base of the rat houses. These feces have be used as garden fertilizer. The commercial use of fertilizer in California has led to the removal of one to three sacks of feces per wood rat nest.
The dusky-footed woodrat (Neotoma fuscipes) is a species of nocturnal rodent in the family Cricetidae. They are commonly called "packrats" or "trade rats" and build large, domed dens that can reach several feet in height. Coyotes and other predators will attempt to prey on these rodents by laying waste to the dens, but the sheer volume of material is usually dissuasive. Occasionally, dusky-footed woodrats will build satellite dens in trees. Although these animals are religiously solitary, except in the mating season (when they are most vulnerable to predation), dens are frequently found in clusters of up to several dozen, forming rough "communities". The mating system in this species appears to be variable, with promiscuity most generally at high population densities and monogamy at lower densities.
They are similar in appearance to the common rat species Rattus rattus and Rattus norvegicus, but with larger ears and eyes, softer coats, and furred tails. The California mouse, Peromyscus californicus, which has similar distribution, is sometimes found living in woodrat dens. Dens contain a nest and up to several "pantry" chambers which are used to store leaves and nuts for future consumption.
Dusky-footed woodrats of California have been found to selectively place California bay leaves (Umbellularia) around the edges of their nest within their stickhouses to control levels of ectoparasites such as fleas. The leaves contain volatile organic compounds which are toxic to flea larvae. Among the terpenes most toxic to flea larvae in the bay leaves are umbellelone, cineole, and cymene. Wood rats are believed to have evolved this behavioral adaptation to cope with the environmental stresses posed by ectoparasites.
- Linzey, A.V. & Hammerson, G. (2008). "Neotoma fuscipes". IUCN Red List of Threatened Species. Version 2009.2. International Union for Conservation of Nature. Retrieved 4 February 2010.
- Musser, G. G. and Carleton, M. D. (2005). "Superfamily Muroidea". in Mammal Species of the World a Taxonomic and Geographic Reference. D. E. Wilson and D. M. Reeder (eds.) pp. 894–1531. Johns Hopkins University Press, Baltimore.
- McEachern, M. B., McElreath, R. L., VanVuren, D. H. and Eadie, J. M. (2009). "Another genetically promiscuous 'polygynous' mammal: mating system variation in Neotoma fuscipes". Animal Behaviour 77 (2): 449. doi:10.1016/j.anbehav.2008.10.024.
- Hemmes, Richard (2002). "Use of California bay foliage by wood rats for possible fumigation of nest-borne ectoparasites". Behavioral Ecology 13 (3): 381. doi:10.1093/beheco/13.3.381.
- Vassar College, URSI projects 2006 and 2007, Prof. Richard B. Hemmes and Edith C. Stout, Students Anna Payne-Tobin, Camille Friason, and Michael Higgins. The Role of Monoterpenes from California Bay in Nest Ectoparasite Control by Dusky-Footed Wood Rats, and Behavioral Adaptations to Parasites: Are Wood Rats Using Plant Essential Oils to Control Nest Ectoparasites?
Names and Taxonomy
Comments: Based on concordant patterns of morphological and mtDNA variation, Matocq (2002) split N. fuscipes into two species, N. fuscipes (dusky-footed woodrat) and N. macrotis (large-eared woodrat). This change was adopted in the North American mammal checklist by Baker et al. (2003). Musser and Carleton (in Wilson and Reeder 2005) also recognized the two as different species but applied the name "big-eared woodrat" to N. macrotis.