Home/Species/ Coypu

Myocastor coypus

(Molina, 1782)

Coypu

G5Secure Found in 4 roadless areas NatureServe Explorer →

G5SecureGlobal Rank

Least concernIUCN

Identity

Unique IDELEMENT_GLOBAL.2.102549

Element CodeAMAFK01010

Record TypeSPECIES

ClassificationSpecies

Classification StatusStandard

Name CategoryVertebrate Animal

IUCNLeast concern

Endemicoccurs (regularly, as a native taxon) in multiple nations

KingdomAnimalia

PhylumCraniata

ClassMammalia

OrderRodentia

FamilyEchimyidae

GenusMyocastor

Other Common Names

Castor des marais (FR) Coypo, Nutri (ES) Nutria (EN) nutria (EN) Ragondin (FR) Ratão-do-Banhado (PT)

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/.

Taxonomic Comments

Moved from Myocastoridae to Echimyidae (ASM 2025, Galewski et al. 2005).

Conservation Status

Rank MethodExpertise without calculation

Review Date2016-04-04

Change Date1996-11-15

Range Extent Comments

Native to South America (southern Brazil, Paraguay, Uruguay, Bolivia, Argentina, and Chile). Introduced in Louisiana in 1930s, transplanted in various parts of U.S. by weed control promoters. Most successful in southcentral U.S. U.S. range includes southeastern U.S., Oregon, Washington, Oklahoma, and Maryland. Introduced also in British Columbia, Europe, northern Asia, and eastern Africa.

Ecology & Habitat

Habitat

Prefers freshwater marshes; also in brackish marshes. Nests in burrows, abandoned muskrat houses, or in dense vegetation.

Ecology

Home range probably is less than 2.5 acres. Can become very abundant. May displace muskrat populations, though the two species may coexist where conditions are "good" (Jackson 1990). In Maryland, population density was estimated at 3-16 per ha; trapper harvest, and in one year, freezing, accounted for most mortality (Willner et al. 1979). Commonly preyed on by alligators. Lifespan generally is 2-3 years or less.

Reproduction

Breeds year-round. Gestation lasts 130 days. Produces several litters of 3-5 young per year; estimated annual productivity was 8 young per female in Maryland; oldest females were 3 years old (Willner et al. 1979). Sexually mature in 4-8 months, depending on environmental conditions.

Terrestrial Habitats

Cropland/hedgerow

Palustrine Habitats

HERBACEOUS WETLAND

Other Nations (2)

CanadaNNA

Province	Rank	Native
British Columbia	SNA	No
Ontario	SNA	No

United StatesNNA

Province	Rank	Native
Nevada	SNA	No
Washington	SNA	No
Oklahoma	SNA	No
Mississippi	SNA	No
Virginia	SNA	No
Delaware	SNA	No
Oregon	SNA	No
Missouri	SNA	No
North Carolina	SNA	No
New Jersey	SNA	No
New Mexico	SNA	No
Georgia	SNA	No
Utah	SNA	No
Louisiana	SNA	No
Nebraska	SNA	No
Florida	SNA	No
Alabama	SNA	No
Arkansas	SNA	No
Maryland	SNA	No
Texas	SNA	No

Roadless Areas (4)

Oregon (4)

Area	Forest	Acres
Tahkenitch	Siuslaw National Forest	5,799
Tenmile	Siuslaw National Forest	10,818
Umpqua Spit	Siuslaw National Forest	2,090
Woahink	Siuslaw National Forest	5,309

References (23)

American Society of Mammalogists (ASM). 2025. Mammal Diversity Database (Version 1.13) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.10595931. Online. Available: https://www.mammaldiversity.org/
Baker, R. J., L. C. Bradley, R. D. Bradley, J. W. Dragoo, M. D. Engstrom, R. S. Hoffman, C. A. Jones, F. Reid, D. W. Rice, and C. Jones. 2003a. Revised checklist of North American mammals north of Mexico, 2003. Museum of Texas Tech University Occasional Papers 229:1-23.
Caceres, N. C. 2004. Occurrence of <i>Conepatus chinga</i> (Molina) (Mammalia, Carnivora, Mustelidae) and other terrestrial mammals in the Serra do Mar, Paraná, Brazil. Revista Brasileira de Zoologia 21:577-579.
Ceballos, G., J. Arroyo-Cabrales, and R. A. Medellín. 2002. The mammals of México: Composition, distribution, and conservation status. Occasional Papers, Museum of Texas Tech University 218:1-27.
Csuti, B., A. J. Kimmerling, T. A. O'Neil, M. M. Shaughnessy, E. P. Gaines, and M.M.P. Huso. 1997. Atlas of Oregon wildlife: distribution, habitat, and natural history. Oregon State University Press, Corvallis. 492 pp.
Davis, W. B. 1978. The mammals of Texas. Texas Parks and Wildlife Dept., Bull. No. 41. 294 pp.
Eisenberg, J. F. and K. H. Redford. 1989. Mammals of the Neotropics, The Northern Neotropics, Volume 1, Panama, Colombia, Venezuela, Guyana, Suriname, French Guiana. Chicago, The University of Chicago Press.
Eisenberg, J. F. and K. H. Redford. 1999. Mammals of the Neotropics, The Central Neotropics, Volume 3, Ecuador, Peru, Bolivia, Brazil. Chicago, The University of Chicago Press.
Evans, J. 1970. About nutria and their control. U.S. Fish& Wildl. Serv. Res. Publ. 86:1-65.
Galewski, T., J. F. Mauffrey, Y. L. Leite, J. L. Patton, and E. J. Douzery. 2005. Ecomorphological diversification among South American spiny rats (Rodentia; Echimyidae): a phylogenetic and chronological approach. Molecular Phylogenetics and Evolution 34(3):601-615.
Hall, E. R. 1981a. The Mammals of North America, second edition. Vols. I & II. John Wiley & Sons, New York, New York. 1181 pp.
Hamilton, W. J., Jr., and J. O. Whitaker, Jr. 1979. Mammals of the eastern United States. Cornell Univ. Press, Ithaca, New York. 346 pp.
Jackson, D. D. 1990. Orangetooth is here to stay. Audubon, July 1990, pp. 89-94.
Johnson, R. E., and K. M. Cassidy. 1997. Terrestrial mammals of Washington State: Location data and predicted distributions. Volume 3 in Washington State Gap Analysis- Final Report (K. M. Cassidy, C. E. Grue, M. R. Smith, and K. M. Dvornich, eds.). Washington Cooperative Fish and Wildlife Research Unit, University of Washington, Seattle, 304 pp.
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.
Lowery, G. H., Jr. 1974. The mammals of Louisiana and its adjacent waters. Louisiana State University Press, Baton Rouge. 565 pp.
Mammalian Species, nos. 1-604. Published by the American Society of Mammalogists.
Sealander, J. A. and G. A. Heidt. 1990. Arkansas mammals: their history, classification, and distribution. University of Arkansas Press, Fayetteville, Arkansas.
Whitaker, J. O., and W. J. Hamilton. 1998. Mammals of the eastern United States. Comstock Publishing, Ithaca, New York.
Whitaker, J. O., Jr. 1996. National Audubon Society Field Guide to North American Mammals. Alfred A. Knopf, New York, USA. 937 pp.
Willner, G. R., J. A. Chapman, and D. Pursley. 1979. Reproduction, physiological responses, food habits, and abundance of nutria on Maryland marshes. Wildl. Monogr. No. 65:1-43.
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/.
Wilson, D. E., and D. M. Reeder (editors). 2005. Mammal species of the world: a taxonomic and geographic reference. Third edition. The Johns Hopkins University Press, Baltimore. Two volumes. 2,142 pp. [As modified by ASM the Mammal Diversity Database (MDD) at https://www.mammaldiversity.org/index.html]