Nutria can be distinguished by their large, bright orange front teeth. (Peleg/Wikimedia Commons)
Nutria are large, brown, semi-aquatic rodents that live in marshes and wetlands on the Delmarva Peninsula and other parts of the Chesapeake Bay watershed. They are an invasive species.
Appearance:
Dense, gray undercoat guarded by long, coarse hairs that vary in color from yellowish-brown to dark brown
Large, bright orange front teeth
Short legs with large, webbed hind feet that can be nearly 6 inches long
Thin tail that can be 12-18 inches long
Small eyes and ears that are located high on the head
Grows to 2 feet long and weighs 12-15 pounds, but can weigh as much as 20 pounds
Habitat:
Lives in fresh and brackish marshes, swamps, impoundments, farm ponds and other wetlands
Semi-aquatic, meaning it spends time both on land and in the water
Primarily nocturnal, feeding around midnight and resting during the day
Range:
Found throughout the Delmarva Peninsula, concentrated in Dorchester County, Maryland, but ranging from Bombay Hook National Wildlife Refuge in Delaware to Virginia’s Eastern Shore
Also reported in the Potomac and Patuxent rivers in Maryland and in the Rappahannock River and Back Bay National Wildlife Refuge in Virginia
Native to South America, including Argentina, Bolivia, Chile, Paraguay, Uruguay and southern Brazil
Feeding:
Feeds on roots, rhizomes, tubers and young shoots of marsh plants such as cattails, saltmeadow cordgrass and Olney threesquare
Will also eat crops and lawn grasses near its marsh habitat
Consumes approximately 25 percent of its body weight every day
Uses its large front teeth and powerful feet to dig into the marsh and feed on the root mat, causing significant erosion and damage to marshes
Predators:
No natural predators in the Chesapeake Bay watershed
Reproduction and Life Cycle:
Reproduction peaks in late winter, early summer and mid-autumn
Highly prolific breeders, producing 2-3 litters per year
Some nutria dig shallow dens into the mud of marsh banks. Dens have a nesting chamber inside.
Female nutria are pregnant for 128-130 days
Each litter averages 4-5 young nutria, though some litters can have up to 13 young
Females can breed again within two days of giving birth
Young nutria mature quickly. They are able to swim and eat plant material one day after birth and can live on their own after just five days of nursing.
Most young nutria continue to nurse for 7-8 weeks and remain with their mother for about 10 weeks
Reaches sexual maturity at 4-6 months old
Other Facts:
Nutriais a Spanish word for “otter.”
Also known as coypu
Can be mistaken for muskrats or beavers. Nutria can be distinguished by their rounded tail and orange front teeth.
During winter, nutria have been observed gathering in piles to keep warm.
