How do I Identify a Nutria?
Nutria are easily confused with other mammals, particularly those found in and near water. This section will help you to identify nutria from muskrat, beaver, groundhogs, and otters.
Nutria (Myocastor coypus) are a large, aquatic, invasive rodent, native to South America. They have been introduced to coastal wetlands of Maryland, Virginia and North Carolina and are showing signs of continued expansion. This is of concern to natural resource managers because, as populations increase, nutria destroy coastal marsh vegetation through their feeding. These marshlands are critical for a number of ecosystem services such as filtering sediment and contaminants, and providing nursery grounds for a wide range of species. The health of coastal ecosystems and the economies that depend on them, is at increasing risk from nutria.
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This site was designed to provide basic information on identifying nutria and recording their locations to guide management decision making. Our goal is to gather observations from the public in order to better-understand where populations are expanding and why.
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Facial Characteristics
Nutria often have a distinct white muzzle and orange teeth. They also have more pronounced white whiskers than either muskrat or beaver.
Swimming
One of the best ways to tell a nutria from a muskrat is how the swim. Muskrat use their tail for propulsion, so it leaves a distinct "S" pattern in the water. Nutria drag their tails behind them.
This video shows the undulating tail of the swimming muskrat . (Courtesy of clove71 from Instagram)
This gallery contains other images of nutria in the field. These provide a reference for typical nutria encounters .
Nutria are often seen in water adjacent to the bank and eating. (Photo L. Mease)
This image shows a nutria in a grassy area next to a ditch. Nutria will often venture only a few yards from escape cover and water. (Photo D. Bray)
(Photo B. Leber)
Nutria are often seen in water adjacent to the bank and eating. (Photo L. Mease)