BC Conservation Data Centre: Species Summary
Aplodontia rufa
Mountain Beaver
| Scientific Name: | Aplodontia rufa (Rafinesque, 1817) | ||||||||||
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| English Name: | Mountain Beaver | ||||||||||
| English Name Synonyms: |
Sewellel
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| Classification / Taxonomy | |||||||||||
| Scientific Name - Concept Reference: | Wilson, D. E., and D. M. Reeder (editors). 1993. Mammal species of the world: a taxonomic and geographic reference. Second edition. Smithsonian Institution Press, Washington, DC. xviii + 1206 pp. Available online at: http://www.nmnh.si.edu/msw/. | ||||||||||
| Classification Level: | Species | ||||||||||
| Taxonomy Comments: | This species was formerly tracked as two subspecies; Aplodontia rufa rufa and A. rufa rainieri. According to Piaggio et. al. (2013), A. rufa rainieri should be synonymized with A. rufa olympica and A. rufa rufa does not occur north of Oregon. The result is that BC has one species, A. rufa olympica, and thus will be reported out on as A. rufa. |
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| Species Group: | Vertebrate Animal | ||||||||||
| Species Code: | M-APRU | ||||||||||
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| Conservation Status / Legal Designation | |||||||||||
| Global Status: | G5 (Apr 2016) | ||||||||||
| Provincial Status: | S3 (Mar 2024) | ||||||||||
| BC List: | Blue | ||||||||||
| Provincial FRPA list: | |||||||||||
| Provincial Wildlife Act: | |||||||||||
| COSEWIC Status: | Special Concern (Dec 2022) | ||||||||||
| SARA Schedule: | 1 - Special Concern (Jun 2003) | ||||||||||
| General Status Canada: | 4 - Secure (2005) | ||||||||||
| Ecology & Life History | |||||||||||
| General Description: | |||||||||||
| Global Reproduction Comments: | Low rate of reproduction. Monoestrous. Gestation lasts 28-30 days. One litter of 2-4 (usually 2-3) altricial young born March-April, sometimes as late as early May in north. Young are weaned in about 6-8 weeks. Females sexually mature in about 2 years; yearling females may ovulate but do not breed (see Carraway and Verts 1993). A few live up to 5-6 years. | ||||||||||
| Global Ecology Comments: | Usually solitary but may live in loose colonies. Population density estimates generally range from 4 to 8 per hectare, but up to 15-20/ha (see Carraway and Verts 1993). Home range of 10 adult radiotracked for 3-19 months was 0.03-0.20 ha (mean 0.12 ha); moved up to 43 m from nest (see Carraway and Verts 1993). Significant predators include coyote and bobcat. | ||||||||||
| Migration Characteristics: (Global / Provincial) | |||||||||||
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Nonmigrant: Local Migrant: Distant Migrant: Within Borders Migrant: |
Y / N / N / na / |
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| Habitats: (Type / Subtype / Dependence) |
Agriculture / Cultivated Field / Unknown
Agriculture / Hedgerow / Unknown Agriculture / Pasture/Old Field / Unknown Alpine/Tundra / Alpine/Subalpine Meadow / Unknown Alpine/Tundra / Krummholtz / Unknown Forest / Conifer Forest - Dry / Unknown Forest / Conifer Forest - Mesic (average) / Unknown Forest / Conifer Forest - Moist/wet / Unknown Forest / Mixed Forest (deciduous/coniferous mix) / Unknown Grassland/Shrub / Meadow / Unknown Grassland/Shrub / Shrub - Logged / Unknown Grassland/Shrub / Shrub - Natural / Unknown Other Unique Habitats / Avalanche Track / Unknown Riparian / Riparian Forest / Unknown Stream/River / Stream/River / Unknown Subterranean / Sub-soil / Obligate |
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| Global Habitat Comments: | Forested areas from near sea level to timberline. Damp ravines and shaded hillsides in coastal and montane forests with an abundance of herbaceous ground cover. Typically in riparian habitat in moist coniferous forests. Most abundant near water courses in early to mid-seral stages vegetated by a tangle of second growth tree species, shrubs and forbs, and containing debris left from earlier forests (Carraway and Verts 1993). See Beier (1989) for information on habitat in the Sierra Nevada. Prefers damp soils; digs network of tunnels along stream banks. Tunnels generally are just below the ground surface, usually on north slopes in California, on south slopes in British Columbia. Primarily fossorial but can climb trees and swims well (but not arboreal or aquatic). Mostly underground in winter. Oval nests are constructed with leaves, twigs and grasses in a chamber that may be about 2 feet below the surface of the ground. | ||||||||||
| Provincial Habitat Comments: | There are few specific data on the habitat requirements of A. r .rufa in British Columbia. Based on Cosco (1980), Gyug (2000), and Ransome (2003) this subspecies is associated with coniferous, mixed and Red Alder forests on moist slopes or hillsides near small streams or seeps. Humid sites with a dense understory are ideal. An important requirement is deep soils suitable for excavating burrow systems and tunnels. Although tunnels may be in wet soils, the nest sites are located above the water table. Various studies (Carraway and Verts 1993) have shown that this species reaches highest densities in early to mid seral stages. | ||||||||||
| Food Habits: |
Herbivore: Adult, Immature
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| Global Food Habits Comments: | Feeds on a wide variety of vegetation; consumes ferns, forbs, and deciduous plants in summer; conifer foliage in fall/winter if other plants are unavailable (Banfield 1974). Forages mainly above ground (Epple et al. 1993). Requires free surface water or succulent vegetation on a daily basis. Caches grasses and forbs for winter food. Coprophagous. | ||||||||||
| Global Phenology: |
Circadian: Adult, Immature
Crepuscular: Adult, Immature |
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| Global Phenology Comments: | Active during winter. Throughout the 24-hour day in summer, 5-7 periods of activity alternate with periods of rest. More active at night than during daylight hours. | ||||||||||
| Provincial Phenology: (1st half of month/ 2nd half of month) |
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| Colonial Breeder: | N | ||||||||||
| Length(cm)/width(cm)/Weight(g): | 47/ / 1400 | ||||||||||
| Elevation (m) (min / max): |
Global:
Provincial: |
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| Distribution | |||||||||||
| Endemic: | N | ||||||||||
| Global Range Comment: | Pacific coast of western North America, from southwestern British Columbia south to central California. From near Merritt, British Columbia, south along the Cascade, Olympic, Coast, and Siskiyou ranges to Rio Dell, California; Mt Shasta, California, southeastward through the Sierra Nevada of eastern California and west-central Nevada; Point Arena, Mendocino County, California; and near Pt. Reyes, Marin County, California (Carraway and Verts 1993). | ||||||||||
| Authors / Contributors | |||||||||||
| Global Information Author: | Hammerson, G. | ||||||||||
| Last Updated: | May 30, 1995 | ||||||||||
| Provincial Information Author: | |||||||||||
| Last Updated: | |||||||||||
| References and Related Literature | |||||||||||
B.C. Ministry of Environment. Recovery Planning in BC. B.C. Minist. Environ. Victoria, BC. |
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Banfield, A. W. F. 1974. The mammals of Canada. University of Toronto Press, Toronto, Canada. 438 pp. |
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Beier, P. 1989. Use of habitat by mountain beaver in the Sierra Nevada, J. Wildl. Manage. 53:649-654. |
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Carraway, L. N., and B. J. Verts. 1993. Aplodontia rufa. Am. Soc. Mamm., Mammalian Species No. 431:1-10. |
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Carraway, L.N., and B.J. Verts. 1993. Aplodontia rufa. Am. Soc., Mammalian Species No. 431:1-10. |
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Cosco, J. 1980. Mountain beaver (Aplodontia rufa): its biology and implications to forestry in British Columbia. B.S.F. Thesis, Faculty of For., Univ. B.C. 108pp. |
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Engeman, R. M., D. L. Campbell, and J. Evans. 1991. An evaluation of two activity indicators for use in mountain beaver burrow systems. Wildl. Soc. Bull. 19:413-416. |
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Epple, G., et al. 1993. Effects of predator odors on feeding in the mountain beaver (APLODONTIA RUFA). J. Mamm. 74:715-722. |
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Gyug, L.W. 2000. Status, distribution, and biology of the Mountain Beaver, Aplodontia rufa, in Canada. Can. Field-Nat. 114(3):476-490. |
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Hubbard, C.A. 1922. Some data upon the rodent Aplodontia. Murrelet 3:14-18. |
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Ingles, L. G. 1965. Mammals of the Pacific States. Stanford University Press, Stanford, California. |
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Jones, J. K., Jr., R. S. Hoffman, D. W. Rice, C. Jones, R. J. Baker, and M. D. Engstrom. 1992a. Revised checklist of North American mammals north of Mexico, 1991. Occasional Papers, The Museum, Texas Tech University, 146:1-23. |
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Martin, P. 1971. Movements and activities of the mountain beaver (Aplodontia rufa). J. Mammal. 52:717-723. |
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Nagorsen, D. W. 2005b. The rodents and lagomorphs of British Columbia. Royal B.C. Mus. Handb., Victoria, BC. 410pp. |
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Nagorsen, D.W. 2002. An identification manual to the small mammals of British Columbia. B.C. Minist. Sustainable Resour. Manage., and Minist. Water, Land and Air Prot., and Royal B.C. Mus., 153pp. |
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Pfeiffer, E.W. 1958. The reproductive cycle of the female mountain beaver. J. Mammal. 39:223-235. |
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Ransome, D.B. 2003. Distribution, population dynamics, habitat associations, and the influence of forest management on mountain beavers. Project No. R2003-0123. Unpubl. rep. submitted to B.C. Forestry Innovation Investment. DBR Forestry-Wildl. Integrated Manage., Mission. 46pp. |
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Todd, P. A. 1992. Mountain beaver habitat use and management implications in Yosemite National Park. Natural Areas Journal 12:26-31. |
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Wilson, D. E., and D. M. Reeder (editors). 1993. Mammal species of the world: a taxonomic and geographic reference. Second edition. Smithsonian Institution Press, Washington, DC. xviii + 1206 pp. Available online at: http://www.nmnh.si.edu/msw/. |
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Please visit the website Conservation Status Ranks for definitions of the data fields used in this summary report.
Suggested Citation:
B.C. Conservation Data Centre. 1995. Species Summary: Aplodontia rufa. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Mar 10, 2026).