J.B. Pritzker, Governor |


(Myocastor coypus)

Sergii Koviarov from Pixabay-nutria7089358
Two nutria sitting in the water near the streambank.

Did You Know?

Nutria (Myocastor coypus) are native to South America and are considered an invasive species in the United States.

They were brought to the U.S. in the late 1800s by fur farmers looking to raise them for their (then) valuable pelts. The animals escaped or were turned loose as the fur market declined in the 1940s. Some of the escaped nutria survived and thrived, establishing populations and spreading across the south and into the northeast U.S.

Negative impacts caused by nutria range from compromising levees when they dig their burrows, damaging crops, and ecological disruptions caused by excessive removal of native plants in wetland systems. Nutria can also carry diseases including tuberculosis and septicemia as well as parasites including various flukes, tapeworms and nematodes.

Click to expand.

Report Nutria Sightings in Illinois

Please send an email with the subject line as “nutria sighting” to with information about any nutria that have been trapped or found (e.g., roadkilled nutria). Due to the similarities of nutria to beaver and muskrats, the IDNR is not collecting information on nutria sightings that cannot be verified.

Click to expand.

Description & Identification

Nutria are dark-colored, semi-aquatic rodents that resemble muskrats and small beavers. There are several characteristics can be used to differentiate between the three species.

USFWS National Digital Library
Two nutria laying on their shelter in a wetland.
Two nutria laying on their shelter in a wetland.

Nutria are larger than muskrats but smaller than beavers, and their backs are more arched. Additionally, nutria have white muzzles and long, white whiskers, while muskrats and beavers have black whiskers.

The tails are another distinguishing feature. Nutria have long, round tails that may become shortened due to frostbite during cold Illinois winters. In comparison, beavers have broad, paddle-like tails and muskrats have thin, laterally flattened tails. When in the water, muskrats move their tails in a snake-like fashion as they swim, whereas nutria drag their heavy, rat-like tails behind them while swimming.

Average Length: 36 to 42 inches including the tail

Average Weight: 15 to 20 pounds


Differences at a Glance

Characteristics             Nutria             Beaver            Muskrat
Tail Heavy, round and rat-like Broad and paddle-like Laterally flattened
Weight 15-20 pounds 25-60 pounds 1.5-4 pounds
Body Length 24 inches 31-41 inches 10-14 inches
Tail Length 12-18 inches 10-20 inches 8-11 inches
Whiskers white black black
Lodging Platform of dead vegetation or burrow Lodge of mud and sticks Mounded hut of mud and vegetation

Click to expand.


Size comparison of a six-foot man, muskrat, nutria, and beaver.
Size comparison of a six-foot man with a muskrat (left side), nutria (middle), and beaver (right side next to the man).

Click to expand.

Signs: Tracks

Nutria tracks can reach up to 6 inches long. They have 5 toes per foot and have webbing on the hindfeet.

Click to expand.

Behavior & Reproduction

Nutria primarily eat vegetation but will also consume invertebrates such as mussels and snails. They are skilled at digging and readily excavate burrows and build platforms for feeding and nesting. While nutria are generally nocturnal, they can be observed early and late in the day.

Nutria breed throughout the year and can have up to 3 litters per year, averaging 4-6 young. There are few native predators large enough to take down adult nutria, allowing populations to grow rapidly. Population status is currently unknown in Illinois since so few animals have been verified.

Negative impacts caused by nutria range from compromising levees when they dig their burrows, to crop damage, and ecological disruptions caused by excessive removal of native plants in wetland systems.

Click to expand.

Distribution & Abundance

Nutria are native to South American and were brought to the United States in the late 1800s by fur farmers. Escaped and released animals survived and spread across the southern U.S. and the northeast U.S. Nutria have been documented moving up the Mississippi River Valley and are found in Missouri, Arkansas,Tennessee and Kentucky. To date, there are no coordinated eradication efforts reported from these states, but most have opened their trapping seasons to include nutria during the regular beaver, muskrat, and otter seasons.

Nutria in Illinois?

Anecdotal reports of nutria have been received from various locations in southern Illinois since the early 2000s. Despite multiple reports from credible sources, documentation corroborating these reports was limited.

Credible reports with minimal documentation:

  •  In the early 2000s, there were observations from duck hunters with the USDA Forest Service in the Cache River.
  • Around 2010, IDNR Conservation Police found a roadkilled nutria at Horseshoe Lake, but no carcass or photos were presented.
  • In the 2010s, there was an incidental capture by site staff or site trappers at Mermet Lake, but again there were no photos or carcass. Additionally, staff at Cypress Creek National Wildlife Refuge observed a live nutria southeast of Perks.
  • In 2019 or 2020, a Pulaski County, Illinois fur buyer purchased pelts from a trapper in Ballard County, Kentucky.
  • On June 24, 2021, at the Cache River State Natural Area near Karnak, a photo of a roadkilled nutria was posted on social media. While there was no carcass during the site visit, the IDNR Distric Wildlife Biologist verified the location.
  • On April 19, 2022, an IDNR Natural Heritage Biologist observed a nutria at Lovet’s Pond Nature Preserve in Jackson County, Illinois.

Illinois verified nutria (with documentation):

  • On February 14, 2022, two nutria were incidentally captured in two beaver traps in Round Pond in Pope County. These animals were verified by an IDNR District Wildlife Biologist.

Click to expand.

Actions Being Taken


The IDNR is working with researchers from Southern Illinois University-Carbondale (SIUC) to identify and sample priority habitats in southern Illinois. Work includes:

  • Semi-aquatic mammal surveys conducted by SIUC in cooperation with USDA Wildlife Services
  • Identification of nutria and/or populations of nutria in southern Illinois
  • Establishment of a reporting system to identify nutria locations
  • Evaluation of the best methods to remove nutria

   Detection methods considered

  • USDA trained dogs (used in Chesapeake Bay eradication program)
  • E-DNA water sampling
  • Scent stations

Removal efforts

Nutria removal efforts in Illinois will need to be a coordinated effort. It will also be necessary to assess the impacts that nutria have on wetland ecology, agriculture, and infrastructure. The IDNR is working with USDA Wildlife Services to assess and remove nutria populations where found in Illinois. Additionally, the IDNR encourages private landowners and wildlife-related non-profit organizations and agencies (i.e., The Nature Conservancy, American Land Conservancy, U.S. Fish and Wildlife Service, etc.) to trap and remove nutria on properties that they own and manage.

Click to expand.