Myocastor coypus in New Jersey Invasive Species Strike Team

Common Name: nutria, Coypu
Family Name: Myocastoridae - Nutria family
Species Code: MYCO1
Native range: South America
NJ Status: Emerging Stage 0 – Absent or very rare. It is highly threatening to native plant communities.

General Description

• Large, herbivorous, semi-aquatic rodent
• Introduced to the US in 1930s and farmed for their fur
• Adults weight 15 to 22 lbs (males larger than females) and 24” long (tail included).
• Long, rounded, sparsely haired tail measuring 13 - 16”
 Large yellow orange teeth
• Life span of 8 to 10 years
• Nocturnal, will feed during the day if food is scarce
• Nutrias eat 25% of their body weight daily.
• Eats roots, rhizomes, and tubers of plants.
• Will create burrows, land nests, and platforms out of vegetation in shallow water

Life Cycle

• Sexually mature after 4 months
• Females average 4 to 5 offspring per pregnancy, can have 2 litters per year
• Male and 2 to 3 females share a den

What to look for

• Tracks show a small fore foot and a larger hind foot, 5”, with four webbed toes and a free outer toe. Tail drag marks are also seen between the footprints
• Droppings dark green to black, 2” long and ½” wide, deep lines running along the droppings

Habitat

• Wetlands, semi-aquatic environments
• Prefers places with a large amount of emergent aquatic vegetation

Look-alikes

beaver (Castor canadensis)

• Native
• Adults measure 3’ long and weighing 44 lbs on average
 Flat, wide, tail
• Creates large dens out of sticks twigs and mud

muskrat (Ondatra zibethicus)

• Native • Adults measure 16 - 24” long, their tail measuring 9½” long, and weight between 1½ - 4 lbs
• Over winters in a den made of vegetation and mud, creates a new one each year.
 Mark their territory with a musky sent
 Hind foot not webbed and all toes point forward