Invasive Species Alert: Nutria Rats Eliminated From Maryland; Can Other States Do The Same?

Nutria sounds pretty good. Could it be a healthy protein drink? No, Nutria (Myocastor coypus) are large spiny rats native to South America. Nutria rats are problems in much of the United States.

close up of nutria
Nutria rats have few friends due to their destructive habits. by Jorge Bilbao on

According to the US Department of Agriculture (USDA) the rodents, which reach up to 20 pounds, may have arrived in the United States as early as 1889. Humans brought them here for the nutria fur trade. That fur trade collapsed in the 1930’s and an unknown number were released. The fur is still used to some extent, as lining for raincoats. It is cheap fur, under $2 a pelt.

selective focus photography of crocodile
Alligators eat nutria rats in southern states. but apparently not enough. Photo by Adriaan Greyling on

The fur trade took a further blow in the 1980’s as fashion turned against animal hide. Attempts to reconsider nutria rat fur as a socially acceptable fur have been attempted. The idea being that nutria are invasive troublemakers (in much of the world) and turning them into fashionable coats is a good thing.

And how much trouble do they really cause?

The FDA says:

“Nutria are most abundant in the Gulf Coast States, but they also cause
problems in other southeastern States, the Pacific Northwest, and along
the Atlantic coast. In addition to damaging vegetation and crops, nutria
destroy the banks of ditches, lakes, and other water bodies. Of greatest
significance, however, is the permanent damage nutria can cause to
marshes and other wetlands.
In these areas, nutria feed on native plants that hold wetland soil together.
The destruction of this vegetation intensifies the loss of coastal marshes
that has been exacerbated by rising sea levels.”

They also have health implications:

“Nutria also can impact public health and safety. The
rodents can serve as hosts for several pathogens,
including tuberculosis and septicemia, which can
infect people, pets, and livestock. In addition, nutria
can carry parasites, such as blood flukes, tapeworms,
and liver flukes and a nematode known to cause a
rash called “nutria itch.” Many of these organisms—
found in nutria feces and urine—can contaminate
drinking water supplies and swimming areas.”

They are currently found in 20 of the 50 states, but one state apparently can be crossed off the list: Maryland. Like other nutria they came as fur bearers, but were released.

After decades of work the state has been declared nutria free. The FDA said the project took 20 years and involved cooperation between landowners, local state and federal government and related agencies.

woman wearing black fur coat
Nutria were introduced for the fur industry. Some hope a nutria fur resurgence may help make a dent in the population Photo by Marlon Schmeiski on

Hunting and trapping were important tools. But they were aided by higher tech methods and tracker dogs. Dogs could find nutria rat droppings and locate the animal. The FDA said the basic cause for success was hard daily work locating and removing the creatures.

Dogs are important in the fights against pythons and feral hogs. Dos aren’t the only tools. Collared male pythons lead hunters to females, breaking the reproduction cycle. Collared hogs lead trappers to hog families which can be removed.

Published by ursusrising

long time writer and editor living in Los Angeles

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