Oklahoma State University
Oklahoma Invasive Species
Oklahoma State University

Myocastor coypus

Country of Origin: Nutria’s original ranges include: Argentina, Chile, Bolivia, Uruguay, Paraguay and southern Brazil. (NAS)
History: Nutria are found in 16 U.S. states, they are South American natives.  Nutria distribution is in fresh and brackish marshes, rivers, bayous, farm ponds, freshwater impoundments, drainage canals, swamps and various other types of wetlands. (Nutria)
Intended Use: Nutria were imported into the U. S. between 1899 and 1930 for the fur trade to help in the decline of the beaver.  Many nutria were released into the wild, because of poor captive breeding. (NAS)
Mode of Invasion:

Nutria are highly prolific and breed all year.  Female gestation period is 128 to 130 days and are able to breed within 48 hours of giving birth.  Litter size ranges from two to 11 offspring.  The Nutria reaches sexual maturity at four to five months of age.  Nurtria are herbivores.  Their daily consumption is about 25% of their body weight.  These are a few of the things that led the Nutria to become invasive.  (Nutria)

Species Description:

Myocastor coypus are large rodents similar to beavers with long, thin tails that weigh up to 20 lbs.  Dense, grayish under fur overlaid with long shiny guard hairs dark brown to yellowish brown.  Nutria are nocturnal (active at night) with high activity occurring near midnight. (Nutria)

Map of Occurrence:


Effects of Invasion:

Enviromental Impacts:

Nutria eat the vegetation of the wetland below the waterline causing the banks of the wetland to become un-rooted, therefore, become unstable and prone to erosion.  Marsh loss removes the habitat for the native wildlife species including waterfowl, wading ducks, and muskrats.  (Nutria Eating LA’s Coast)


Economic and Human Impacts:

Nutria destroys any crops and cropland near the inhabited wetland. (Nutria Eating LA’s Coast)


Trapping with incentives and relocation, the incentives would include money and or goods.  Complete eradication of the species from seriously damaged areas. There is a reward of five dollars per Nutria tail that is delivered in Louisiana.  They are also consumed by humans as a meat source.  (Blackwater Nat. Wildlife Ref.)


Blackwater National Wildlife Refuge  http://www.fws.gov/blackwater/nutriafact.html


Boxrucker, J., Gilliland, G., Wentroth,B..  Oklahoma Aqutic Nuisance Speices Management Plan.  2008.  Oklahoma Department of Wildlife Conservation.Introduced Species Summary Project Nutria (Myocastor coypus)



Nurtia  http://www.aphis.usda.gov/lpa/pubs/fsheet_faq_notice/fs_wsnutria.pdf


Nutria, Eating Louisiana’s Coast www.nwrc.usgs.gov/factshts/020-00.pdf


USGS.  NAS-Nonindigenous Aqutic Sepcies  http://nas.er.usgs.gov/taxgroup/mammals/