Illinois officials on lookout for invasive, semi-aquatic rodent. How to report sightings

Southern Illinois has seen a couple of verified reports of an invasive species native to South America in the last couple of years, and anyone who sees one is asked to make a report to the Illinois Department of Natural Resources.

The nutria, which has been spotted in the southern tip of the state, is a semi-aquatic rodent that’s larger than a muskrat but smaller than a beaver, according to IDNR.

Only two reports of nutria have been verified in the state in recent years, both in Pope County in 2022, IDNR wildlife diversity program manager Stan McTaggart confirmed in a recent email to the BND, but several credible reports have been made since the early 2000s.

Nutria are also occasionally found in wetland habitats in northwestern Kentucky and southeastern Missouri along the Mississippi and Ohio rivers, McTaggart added. Here’s what to know about the invasive species and what to do if you see one.

More on nutria

Nutria are considered invasive in the U.S. and can harm levees, crops and wetland systems. They can also carry diseases such as tuberculosis and septicemia, as well as parasites like flukes, tapeworms and nematodes , IDNR reports.

Experts at Southern Illinois University Carbondale and IDNR are researching semi-aquatic mammals including beavers, mink, muskrats, river otters and others to determine if there are any nutria populations in southern Illinois. Preliminary results indicate nutria are not well-established in southern Illinois wetlands, McTaggart said.

“We are concerned about nutria damaging our wetland ecosystems because of their voracious appetites and habit of feeding on wetland plants and digging to get to their roots,” McTaggart said. “We are hopeful that the few nutria found were dispersers and not able to establish populations. The effects of this invasive species to our native wetland ecosystems are unknown, but we want to stay on top of it. In other parts of the country, nutria have had significant negative effects on coastal marshes.”

Nutria weigh 15 to 25 pounds on average , according to the Missouri Department of Conservation, and are typically 30 to 42 inches long. They have white whiskers, while beavers and muskrats have black whiskers.

If you find an animal you believe is a nutria at or adjacent to a wetland in southern Illinois, you can submit a report with a high-quality photo to IDNR online. McTaggart said people should examine photos of other semi-aquatic animals online to be sure what they saw was a nutria, as native species are much more common and can be easily mistaken for nutria.

While nutria are native to South America and thrive in the warmer climate there, warming temperatures in southern Illinois may allow more members of the species to survive there , the Southern Illinoisan reported Aug. 22.

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