BC Conservation Data Centre: Species Summary
Lontra canadensis
North American River Otter
| Scientific Name: | Lontra canadensis (Schreber, 1777) | ||||||||||
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| English Name: | North American River Otter | ||||||||||
| Classification / Taxonomy | |||||||||||
| Scientific Name - Concept Reference: | Jones, C., R. S. Hoffman, D. W. Rice, M. D. Engstrom, R. D. Bradley, D. J. Schmidly, C. A. Jones, and R. J. Baker. 1997. Revised checklist of North American mammals north of Mexico, 1997. Occasional Papers, Museum of Texas Tech University 173:1-20. | ||||||||||
| Classification Level: | Species | ||||||||||
| Species Group: | Vertebrate Animal | ||||||||||
| Species Code: | M-LOCA | ||||||||||
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| Conservation Status / Legal Designation | |||||||||||
| Global Status: | G5 (Apr 2016) | ||||||||||
| Provincial Status: | S5 (Mar 2025) | ||||||||||
| BC List: | Yellow | ||||||||||
| Provincial FRPA list: | |||||||||||
| Provincial Wildlife Act: | |||||||||||
| COSEWIC Status: | |||||||||||
| SARA Schedule: | |||||||||||
| General Status Canada: | 4 - Secure (2005) | ||||||||||
| Ecology & Life History | |||||||||||
| General Description: | |||||||||||
| Global Reproduction Comments: | Implantation is delayed 8 months or more. Gestation, including delayed implantation, lasts 9-12 months. In many areas, births peak in late winter-early spring; parturition dates may not be closely synchronized within a given population. Litter size is 1-6 (average 2-3); 1 litter per year. Young may first enter water at about 7 weeks, are weaned at about 3 months, stay with mother for about a year. Male may rejoin family after young leave den. Females breed for the first time at 2 years. Males become sexually mature at 2 years, but may not breed successfully until 5-7 years old. Females evidently breed in alternate years in some areas (e.g., Alabama, Georgia), every year in Oregon (see Toweill and Tabor 1982). | ||||||||||
| Global Ecology Comments: |
Home range typically is linear; 20-30 miles for a pair or male; less for females with young (Jackson 1961). May hunt over as much as 80-100 km of stream during the course of one year. In coastal Alaska, summer home range size averaged around 20 km of shoreline in males, 10 km in females, with ranges twice as large in oiled areas (Bowyer et al. 1995). Population density of one per 2.2 miles has been recorded (Baker 1983). Density was estimated at one otter per 86 ha of coastal marsh in Louisiana (Shirley et al. 1988). In Idaho, density was one family group and 1-3 subadults or nonbreeding adults per 15 km of waterway, plus one breeding adult male for each 20-30 km of waterway (see Toweill and Tabor 1982). Density in coastal areas of the Gulf of Alaska was 0.30-0.85 otters/km of shoreline (Testa et al. 1994, Bowyer et al. 1995). |
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| 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) |
Forest / Conifer Forest - Mesic (average) / Facultative - occasional use
Forest / Conifer Forest - Moist/wet / Facultative - occasional use Lakes / Lake / Facultative - frequent use Lakes / Pond/Open Water / Facultative - frequent use Ocean / Eelgrass Beds / Facultative - occasional use Ocean / Intertidal Marine / Facultative - frequent use Ocean / Kelp Bed / Facultative - occasional use Ocean / Marine Island / Facultative - occasional use Ocean / Sheltered Waters - Marine / Facultative - frequent use Ocean / Subtidal Marine / Facultative - frequent use Other Unique Habitats / Estuary / Facultative - frequent use Riparian / Riparian Forest / Facultative - frequent use Stream/River / Stream/River / Facultative - frequent use Wetland / Bog / Facultative - frequent use Wetland / Fen / Facultative - frequent use Wetland / Marsh / Facultative - frequent use Wetland / Swamp / Facultative - frequent use |
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| Global Habitat Comments: | Streams, lakes, ponds, swamps, marshes, estuaries (in some areas), beaver flowages, exposed outer coast (Pacific Northwest, Alaska). When inactive, occupies hollow log, space under roots, log, or overhang, abandoned beaver lodge, dense thicket near water, or burrow of other animal; such sites also are used for rearing young. Highly associated with beaver on Mount Desert Island, Maine (Dubuc et al. 1990). Uses traditional haul-out sites along the banks of aquatic habitats. May travel long distances overland, particularly in snow. | ||||||||||
| Food Habits: |
Carnivore: Adult, Immature
Invertivore: Adult, Immature Piscivore: Adult, Immature |
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| Global Food Habits Comments: | Feeds opportunistically on aquatic animals, particularly fishes (mostly slow-moving, mid-size species), frogs, crayfish, turtles, insects, etc., sometimes birds and small mammals. In coastal waters eats marine species (Bowyer et al. 1995). Commonly preys on nesting seabirds in some areas (e.g., Alaska islands). See Toweill and Tabor 1982 for many further details. | ||||||||||
| Global Phenology: |
Circadian: Adult, Immature
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| Global Phenology Comments: | Active in winter, even in fresh deep snow. May be active at any time of day. In Idaho, most active from dawn to midmorning and in the evening (see Toweill and Tabor 1982). | ||||||||||
| Provincial Phenology: (1st half of month/ 2nd half of month) |
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| Colonial Breeder: | N | ||||||||||
| Length(cm)/width(cm)/Weight(g): | 131/ / 13600 | ||||||||||
| Elevation (m) (min / max): |
Global:
Provincial: |
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| Distribution | |||||||||||
| Endemic: | N | ||||||||||
| Global Range Comment: | Throughout most of North America north of Mexico, except the extreme southwestern U.S. Extirpated from large areas of the interior U.S. following European colonization. Has been reintroduced in some parts of the range (e.g., Colorado, Virginia). | ||||||||||
| Authors / Contributors | |||||||||||
| Global Information Author: | Hammerson, G. | ||||||||||
| Last Updated: | Dec 16, 1997 | ||||||||||
| Provincial Information Author: | |||||||||||
| Last Updated: | |||||||||||
| References and Related Literature | |||||||||||
Baker, R. H. 1983. Michigan mammals. Michigan State University Press. 642 pp. |
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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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Berg, W. E. 1982. Reintroduction of fisher, pine marten, and river otter. Pages 159-173 in G. C. Sanderson, editor. Midwest furbearer management. Proc. Symp. 43rd Midwest Fishand Widlife Conference, Wichita, Kansas. |
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Bowyer, R. T., J. W. Testa, and J. B. Faro. 1995. Habitat selection and home ranges of river otters in a marine environment: effects of the Exxon Valdez oil spill. Journal of Mammalogy 76:1-11. |
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Caire, W., J. D. Tyler, B. P. Glass, and M. A. Mares. 1989. Mammals of Oklahoma. University of Oklahoma Press, Norman. Oklahoma. 567 pp. |
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Dubec, L. J., W. B. Krohn, and R. B. Owen, Jr. 1990. Predicting occurrence of river otters by habitat on Mount Desert Island, Maine. J. Wildl. Manage. 54:594-599. |
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Engelstoft, C. and F. Mogensen. 2005. Marine-living Northern River Otter health and their feasibility as a sentinel species along the coast of southern Vancouver Island. Report prepared for Dr. Helen Schwantje, Biodiversity Branch, Ministry of Environment. Victoria, BC. 33pp. |
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Godin, A. J. 1977. Wild mammals of New England. Johns Hopkins University Press, Baltimore. 304 pp. |
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Hall, E. R. 1981a. The Mammals of North America, second edition. Vols. I & II. John Wiley & Sons, New York, New York. 1181 pp. |
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Hamilton, W. J., Jr., and J. O. Whitaker, Jr. 1979. Mammals of the eastern United States. Cornell Univ. Press, Ithaca, New York. 346 pp. |
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Herkert, J. R., editor. 1992. Endangered and threatened species of Illinois: status and distribution. Vol. 2: Animals. Illinois Endangered Species Protection Board. iv + 142 pp. |
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Jackson, H. H. 1961. Mammals of Wisconsin. University of Wisconsin Press, Madison. 504 pp. |
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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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Reid, D. G., et al. 1987. A possible method for estimating river otter, Lutra canadensis, populations using snow tracks. Canadian Field-Nat. 101:576-580. |
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Schwartz, C. W., and E. R. Schwartz. 1981. The wild mammals of Missouri. University of Missouri Press, Columbia. 356 pp. |
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Serfass, T. L., R. P. Brooks, and L. M. Rymon. 1993. Evidence of long-term survival and reproduction by translocated river otters, LUTRA CANADENSIS. Can. Field-Nat. 107:59-63. |
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Shirley, M. G., et al. 1988. Population estimates of river otters in a Louisiana coastal marshland. J. Wildl. Manage. 52:512-515. |
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Shump, K.A., Jr., A.U. Shump, R. A. Aulerich, and G.A. Heidt. 1976. A bibliography of Mustelids. Part V: Otters, Michigan State Univ., Agri. Exp. Sta. Jour. Art. No. 7759, 32 pp. |
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Tango, P. J., E. D. Michael, and J. I. Cromer. 1991. Mating and first-season births in interstate transplanted river otters, LUTRA CANADENSIS (Carnivora: Mustelidae). Brimleyana 17:53-55. |
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Testa, J. W., D. F. Holleman, R. T. Bowyer, and J. B. Faro. 1994. Estimating populations of marine river otters in Prince William Sound, Alaska, using radiotracer implants. Journal of Mammalogy 75:1021-1032. |
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Toweill, D. E., and J. E. Tabor. 1982. River otter LUTRA CANADENSIS. Pages 688-703 in J. A. Chapman and G. A. Feldhamer, editors. Wild mammals of North America: biology, management, and economics. Johns Hopkins Univ. Press, Baltimore. |
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Tumlinson, R., and S. Shalaway. 1985. An annotated bibliography on the North American river otter, LUTRA CANADENSIS. Oklahoma Coop. Fish and Wildl. Res. Unit, Oklahoma State Univ., Stillwater. |
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van Zyll de Jong, C. G. 1987. A phylogenetic study of the Lutrinae (Carnivora; Mustelidae) using morphological data. Can. J. Zool. 65:2536-2544. |
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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. 1997. Species Summary: Lontra canadensis. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 8, 2026).