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Invasive Species: Nutria


(Myocastor coypus)
*Not detected in Michigan*


Report this species: 

Use the Midwest Invasive Species Information Network (MISIN) online reporting tool.

- Or - download the MISIN smartphone app and report from your phone -



  • Approximately 2 feet long with dark brown fur.
  • Large yellow or orange colored front teeth.
  • Thick, rat-like tail covered with bristly hairs.
  • Long white whiskers on either side of nose.

Photo courtesy of U.S. Geological Survey.

Photo courtesy of Saxifraga - Jan van der Sraaten.

Habitat: These semi-aquatic rodents inhabit farm ponds, drainage canals, bayous, freshwater and brackish marshes, swamps, and rivers.

Diet: Nutria’s preferred diet includes bulrush, cordgrass, roots, and rhizomes and tubers of cattails.

Native Range: South America.

Local Concern: Nutria, sometimes call coypu, are hosts for several pathogens and parasites that can infect people, pets, and livestock. Eating, digging, and rooting habits cause erosion and convert healthy marsh into open water habitat. Depredation to crops is another concern regarding nutria, especially considering its relatively high reproductive rate.

U.S. Distribution: Freshwater marshes in coastal areas of the Gulf Coast States.

Potential Means of Introduction: Intentional or accidental release.

Native look-alikes and how you can distinguish them from nutria:

  • American Beaver: Length of between 39 and 47 inches, no white whiskers, wide flat tail with little hair on it.
  • Muskrat: Length of 16-25 inches, no white whiskers, long, rat-like tail that’s slightly flattened on the sides.


Nutria Invasive Species Alert - Printable PDF