Muskrats

Ondatra zibethicus

At-a-Glance

• Peak Breeding Activity: March through November

• Gestation: 22 to 39 days

• Young are Born: Throughout the year

• Number of Litters per Year: One to five, average two

• Adult Weight: 1 ¼ to 4 pounds

• Adult Body Length: 16 to 24 inches including tail

• Migration Pattern: Year-round resident

• Typical Foods: Aquatic vegetation, a few terrestrial plants, clams, frogs, crayfish, and fish

• Nuisance Status: Possible nuisance in ponds and wetlands

Description

Muskrats have two coats of hair. The thick fur undercoat keeps the muskrats warm in

winter, and the outer coat is made up of long, shiny waterproof hairs. The muskrat’s fur is a dark brown that gets lighter around its throat. The tail is long, flattened, and nearly hairless, making it a perfect rudder for swimming.

Habitat and Habits

Swimming is what muskrats do best. They can swim up to speeds of two to three miles per hour. It would take an Olympic swimmer to catch up with them! Muskrats spend much of their time sleeping during the day and slip into the water in the evening. They dive underwater for food, or in search of vegetation for their lodges. Like beavers, muskrats also build lodges. However, their lodges consist of more aquatic vegetation than sticks. Sometimes they even make their own feeding stations to protect themselves from predators while they are eating. These private dining rooms are made from weeds and plants and are built on top of floating rafts of reeds. The muskrat lodges usually have one nesting chamber and several underwater entrances for quick escape routes.

Reproduction and Care of the Young

Females normally produce one to five litters per year, with each litter containing four to seven young. That’s up to 35 young a year! The females will often breed while still nursing. Young are born three to four weeks after breeding and are born hairless. Only two weeks after birth the young muskrats have fur and are able to swim. They are able to take care of themselves within a month and are on their own.