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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

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Photo by Justin Secrist

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  • Decades-long Partnership Eradicates Destructive Nutria Rodents from Maryland

    • Sep 16, 2022
    • DOI. Fish and Wildlife Service.

    • The Chesapeake Bay Nutria Eradication Project (CBNEP) announced at an event at Blackwater National Wildlife Refuge today that Maryland is now free of the exotic, invasive nutria. The U.S. Fish and Wildlife Service (USFWS), U.S. Department of Agriculture’s Wildlife Services (WS), and Maryland Department of Natural Resources (DNR) have worked more than 20 years to make this difficult task -- never accomplished before on this scale -- a success.

  • Factsheet - Nutria, An Invasive Rodent [PDF, 1.48 MB]

    • Apr 2020
    • 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.

Distribution / Maps / Survey Status


Selected Resources

The section below contains highly relevant resources for this species, organized by source.

Council or Task Force
Federal Government
International Government
State and Local Government
  • Integrated Taxonomic Information System. Myocastor coypus. [Accessed Sep 21, 2023].

  • 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.