Common Muskrat

Media
Photograph of a muskrat standing on grass
Scientific Name
Ondatra zibethicus
Family
Cricetidae (New World rats and mice) in the order Rodentia
Description

The common muskrat is a medium-sized mammal that has short front legs with small feet, stronger hind legs with large feet, and a narrow, vertically flattened, scaly tail that is slightly shorter than the combined length of head and body. The tail moves rapidly in a snakelike pattern while swimming. The hind feet are partially webbed. The back is blackish brown, and the sides are lighter brown with a reddish tinge; the underparts are still lighter, shading to white on the throat. Their musk glands produce a mild and inoffensive odor.

Similar species: Two other aquatic rodents in Missouri might be confused with muskrats.

  • The American beaver, found statewide, has a horizontally flattened tail, and it is a larger animal, weighing 26–90 pounds. Its presence in an area is often signified by the distinctively gnawed and felled trees and branches it creates.
  • The introduced nutria, which sometimes occurs in southeastern Missouri, has a tail that is round in cross-section, and at 15–25 pounds, it is intermediate in size between beaver and muskrat. The tail of nutrias trails smoothly behind them when swimming.
Size

Total length: 16–25 inches; tail length: 7–11 inches; weight: 1½–4 pounds.

Where To Find
Muskrat Distribution Map

Statewide.

Muskrats are semiaquatic, living in marshes, sloughs, streams, rivers, ponds, and lakes. Here they dig homes in a stream or pond bank or build large houses out of vegetation in the shallow water. The nest, or den, is reached by means of a tunnel that usually opens under water.

In Missouri, the most important management measure is to regulate the harvest. Where muskrats are too numerous, trapping is the most satisfactory means of control. Hunters and trappers may pursue this furbearer species during its prescribed season.

In marshy areas, muskrats eat rootstocks and stems of cattail and three-square bulrush and the seeds of lotus. In other areas of the state, white clover, corn, and bluegrass are preferred. Muskrats living along Ozark streams eat freshwater clams, snails, crayfish, fish, frogs, and aquatic plants.

Common. The long-term population trend data from various surveys suggest populations are stable.

Life Cycle

Breeding occurs from late winter to mid-September, with 3 peaks, at the ends of March, April, and May. Pregnancy averages 28 days; usually 2 or 3 litters are produced annually by a female. The litters usually contain 4–7 young, which are born blind and nearly helpless and naked. After a week they have coarse gray-brown fur. In another week, their eyes open and they start to swim and dive. At 3 to 4 weeks of age, they are weaned. Most breed for the first time in the following spring.

Muskrat pelts are common on the commercial market; almost all is used in the manufacture of women's coats. The fur is durable; the skin makes strong leather and takes dye well.

Muskrat meat is considered a unique flavor and can be gamey due to musk glands. 

Dried musk is used in making perfumes and in preparing scent for trapping animals.

In old-time Ozark dialect, the "sk" sound in words like "muskrat" was softened to a "sh" sound, and it was common for early American hunters and trappers to pronounce the word as if it were spelled "mushrat." Linguists say this is an example of how Elizabethan English, brought to America by its early colonists, survived in Ozark dialect.

As omnivores, muskrats help control populations of both the plants and the small animals they consume.

The dens, mounds, tunnels, and canals they construct become habitat for other organisms to use.

Muskrats and their young are preyed upon by many predators.

Signs and Tracks Image
Illustration of common muskrat tracks
Signs and Tracks

Front track:

  • 1½ inches long
  • 4 toes usually show; thumb is small but is also sometimes visible
  • Narrower than hind track.

Hind track:

  • 3½ inches long
  • 5 toes.

Other notes:

  • Muskrat are common in marshes, ponds, streams, and similar aquatic places.
  • The dragging tail sometimes leaves tracks.
  • Look for plant cuttings and scat at the water’s edge.
  • Muskrat houses are mounds of plant cuttings and mud, built in shallow water. These can be confused with beaver lodges but are made of nonwoody vegetation.
  • Muskrat also live in bank dens.
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Similar Species

Where to See Species

This area was donated to the Conservation Department by S.P. Glover and W.P. Forman of Shelbyville in 1963.
Cooley Lake was once the main channel of the Missouri River as it flowed along the north side of the river bottom. When the river changed course, a deep oxbow lake was left behind.
This area has a concrete boat ramp and offers access to the Fabius River.
Bittern Bottoms Conservation Area is located in Cass County in the Grand River bottoms about eight miles southeast of Harrisonville.
About Mammals in Missouri
More than 70 species of wild mammals live in Missouri: opossums; shrews and moles; bats; rabbits; woodchuck, squirrels, beaver, mice, voles, and other rodents; coyote, foxes, bear, raccoon, weasels, otter, mink, skunks, bobcat, and other carnivores; deer and elk; and more. Most of us recognize mammals easily — they have fur, are warm-blooded, nurse their young, and breathe air.
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