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Nutria - Photo by Justin Secrist
Scientific Name: 
Myocastor coypus Molina (ITIS)
Common Name: 
Nutria, coypu, coypu rat, nutria rat, swamp beaver
Native To: 
South America (Jojola et al. 2005)
Date of U.S. Introduction: 
First established populations introduced in the 1930s (Jojola et al. 2005)
Means of Introduction: 
Introduced for fur production (Jojola et al. 2005)
Damages vegetation and destroys habitat in wetlands (Jojola et al. 2005)
Current U.S. Distribution: 
Gulf of Mexico coast, Atlantic coast, Pacific Northwest


USDA. APHIS. Wildlife Services.

The nutria (Myocastor coypus), a large, semi-aquatic rodent native to South America, was originally brought to the United States in 1889 for its fur. When the nutria fur market collapsed in the 1940s, thousands of nutria escaped or were released into the wild by ranchers who could no longer afford to feed and house them. While nutria devour weeds and overabundant vegetation, they also destroy native aquatic vegetation, crops, and wetland areas. Recognized in the United States as an invasive wildlife species, nutria have been found in at least 20 States and most recently in California. The nutria’s relatively high reproductive rate, combined with a lack of population controls, helped the species to spread.

USDA. Blog.

Maryland’s eastern shore has seen thousands of acres of protective marshland impacted by the nutria's destructive feeding habits. To protect the valuable resources of Maryland’s Chesapeake Bay, The Chesapeake Bay Nutria Eradication Project (CBNEP) began in 2002 to permanently remove invasive nutria from the marshes of the Delmarva Peninsula and to protect, enhance, and restore the aquatic and river ecosystems they damaged.

USDA. Animal and Plant Health Inspection Service.

An interactive story map. The Chesapeake Bay Nutria Eradication Project (CBNEP) is funded largely by the U.S. Fish and Wildlife Service, and operations carried out by the U.S. Department of Agriculture's Wildlife Services. The program is also supported by a coalition of 25 private, local, state, and federal partners which is critical to the success of the project.
See also: APHIS Interactive Maps to explore plant and animal health or wildlife damage management data

Distribution / Maps / Survey Status

University of Georgia. Center for Invasive Species and Ecosystem Health.
Provides state, county, point and GIS data. Maps can be downloaded and shared.
DOI. USGS. Wetland and Aquatic Research Center.
Provides detailed collection information as well as animated map.



Google. YouTube; DOI. Fish and Wildlife Service.

Selected Resources

The section below contains highly relevant resources for this species, organized by source. Or, to display all related content view all resources for Nutria.

Council or Task Force

Washington State Recreation and Conservation Office. Washington Invasive Species Council.

Aquatic Nuisance Species Task Force.
IUCN. Species Survival Commission. Invasive Species Specialist Group.
Internet Center for Wildlife Damage Management.
See also: Rodents for more fact sheets

Texas Commission on Environmental Quality, Galveston Bay Estuary Program; Houston Advanced Research Center (HARC).

Federal Government
DOI. Fish and Wildlife Service. Chesapeake Bay Field Office.

Smithsonian Institution. Smithsonian Environmental Research Center. Marine Invasions Research Lab.

DOI. USGS. Wetland and Aquatic Research Center.
Provides distribution maps and collection information (State and County).
USDA. APHIS. Wildlife Services.
International Government

National Biodiversity Data Centre (Ireland).

State and Local Government

California Department of Fish and Wildlife.

Louisiana Department of Wildlife and Fisheries.

Maryland Department of Natural Resources. Wildlife and Heritage Service.

Virginia Department of Wildlife Resources.

University of Michigan. Museum of Zoology.
Oregon Sea Grant.
See also: Species Guides for more resources
Pennsylvania State University. Pennsylvania Sea Grant.
See also: Aquatic Invasive Species: Resources for additional species information
Columbia University. Center for Environmental Research and Conservation.


  • Integrated Taxonomic Information System. Myocastor coypus. [Accessed Sep 10, 2014].
  • Jojola, S., G. Witmer, and D. Nolte. 2005. Nutria: an invasive rodent pest or valued resource? In: D.L. Nolte and K.A. Fagerstone (Eds.), Proceedings of the 11th Wildlife Damage Management Conference (Paper 110). Fort Collins, Colo.: National Wildlife Research Center.