Nutria

Myocastor coypus

Nutria are non-native, invasive aquatic rodents with yellowish- or reddish-brown fur. Adults have:

• A dense, soft, gray undercoat guarded by long, coarse hairs.
• Lrge teeth that are yellow or orange in color.
• Short legs with webbed back feet.

Nutria grow five to 10 times larger than our native muskrat, usually weighing between 12 and 15 pounds and measuring 24 inches long.

Where do nutria live?

Nutria live in pairs in fresh and brackish marshes, as well as in rivers, ponds, swamps and impoundments. In the Bay watershed, nutria are mostly found on the Delmarva Peninsula and around Back Bay National Wildlife Refuge in Virginia.

Nutria are mostly active at night and are rarely seen during the day.

What do nutria eat?

Nutria eat the roots, rhizomes and tubers of marsh plants, including bulrush, cordgrass and cattails. They generally feed at the waterline, cutting off or digging up their food and taking it to a feeding platform made of vegetation.

How do nutria breed?

Nutria are highly prolific breeders throughout the year.

• Some nutria dig shallow dens in the mud of marsh banks with a nesting chamber inside.
• Female nutria can produce two to three litters per year. An average litter has four to six young.
• Young nutria mature quickly; they are able to swim and eat plant material after 24 hours of birth and live on their own after just five days of nursing.
• Most young nutria continue to nurse for seven to eight weeks and remain with their mother for about 10 weeks.

Other facts about nutria:

• "Nutria" is a Spanish word for otter. Nutria are native to South America.
• In Maryland, nutria have been observed gathering in piles to keep warm during winter.
• Nutria have been eradicated from Blackwater National Wildlife Refuge, but are still found in localized marshy areas in Maryland and Virginia.