Deer in Spring Landscape

(Myocastor coypus)

Description & Range:

Nutria are large rodents that look like beavers with long, thin tails similar to muskrats. Nutria may weight up to 20 pounds and reach about 24 inches from tip of nose to tip of tail. Nutria have thick brown fur and orange front teeth. They are designed for aquatic life, with webbed feet and eyes, nostrils and ears located high on their heads to enable them to expose as little of their bodies as possible when breathing at the surface of the water.

Nutria are native to South America and now can be found in 22 states. Nutria were introduced to Blackwater National Wildlife Refuge in the 1940s, where they were farmed for fur. Currently, nutria can be found on the Eastern Shore of Maryland as well as in the Potomac and Patuxent rivers on the Western Shore.

Two Nutria photo by Steve Hillebrand, USFWS


Nutria can be found within wetlands such as fresh and brackish marshes, rivers, bayous, farm ponds, freshwater impoundments, drainage canals, swamps.


Nutria are herbivores, so they feed entirely on plants. Nutria eat wetland plants such as Three-square rush. Nutria can consume 25% of their body weight per day and tend to eat the roots of wetland vegetation, often causing erosion in wetlands. Occasionally, nutria will feed on crops.


Nutria breed year round and have a gestation period of 130 days. Males are able to reproduce at 4-9 months of age while females can reproduce at 3-9 months of age. Nutria can have 1-13 young per litter, and females can breed the day after they give birth to a litter.

Captive Nutria photo by Christine Eustis, USFWS


Nutria spend much of their time in the water. They are colonial species which tend to live in groups consisting of a dominant male with 2-3 females and their offspring. These groups live in dens and are most active at night. If food is limited, then nutria will become active during the day to feed.


Nutria are an invasive species in Maryland due to their destructive feeding habits on marshes. Nutria are managed as a furbearer species in Maryland, and currently, a nutria eradication program is in progress. To learn more about furbearer management, then click here. To see some commonly asked questions about Nutria, then click here. Finally, if you are interested in more information on invasive species found in Maryland, then click here.

Bank erosion caused by Nutria photo by Tess McBride, USFWS