South American Nutria, Myocastor coypus

The South American nutria, a furry, plant-eating rodent, is native to Argentina, Bolivia, Chile, Paraguay, and Uruguay. It was brought to the United States in 1899 for its fur, but it wasn't until the 1930's that the animal found its way from captivity into the wild. A furrier released six breeding pairs on Avery Island, LA, to start a commercial breeding farm. Over the course of 2 years, several animals escaped and established colonies elsewhere on the island. Then, in 1940, a hurricane washed Avery Island clean of nutria. Unfortunately, these nutria were scattered to other parts of the State, where they continued to breed and expand their range. Eventually, nutria spread throughout Alabama, Georgia, Mississippi, Texas, and Florida. Now, they can be found throughout the United States thanks to subsequent importers who brought them into the country for food and fur.

Nutria have big, buck teeth like beavers but lack the beaver's wide, flat tail. The tail of a nutria is long, thin, and hairy and looks like a rat¹s tail. As the animals swim, their tail floats on the surface behind them. Frequently, they can be found in streams, lakes, ponds, and swamps. They reproduce rapidly, often having two or three litters a year with five to eight young in each. Adult nutria generally grow more than 12 inches (30 cm) long, not including the tail, and weigh as much as 18 lb (8 kg).

Originally, scientists thought that nutria could offer potential as biological control agents for undesirable water vegetation. It turns out that they are excellent in this role. They will eat aquatic weeds and other noxious plants to the point of eradication. The problem is that they will also eat all the good plants. In fact, they will even come out of the water to dine on crops of cabbage, corn, lettuce, peas, etc. While this poses an obvious threat to agricultural resources, nutria do even more damage to marshes and swampland. These pests will clear a marsh of its plants and leave behind nothing but a big, muddy hole in the ground.

Nutria can act as vectors for wildlife diseases and have been known to spread tuberculosis, false tuberculosis, and septicemia. Through their excretions, nutria can pass paratyphoid and parasites to people. Basically, nutria are bad news no matter how you look at them.