Common Muskrat, Odatra zibethicus

The Common Muskrat is a semi-aquatic rodent and an excellent swimmer, partly due to its rudder-like tail, it is found state-wide in Tennessee.

Description: A medium-sized rodent with a large head, stocky body, short legs, and a scaly, vertically flattened tail that is slightly shorter than the total body length.   The dense, glossy fur on the back is blackish-brown with lighter brown (sometimes reddish or yellowish tinged) on the sides. Undercoat is paler and the throat is white.   Eyes and ears are small and a black spot occurs on the chin.   The larger hind feet are partially webbed.

Length: 16.0 - 25.3 inches
Tail:  7.0 - 11.5 inches
Ears:  0.8 - 1.0 inches
Weight: 1.5 - 4.0 pounds

Similar Species:
Nutria is larger and has a round tail.
Northern American River Otter is larger and has a fully furred tail that tapers from a broad base to a point.
American Beaver is much larger with a very large, horizontally flattened tail.

Habitat:  Prefers still or slow moving water habitats such as lakes, ponds, streams, rivers, drainage ditches, or wetlands.   Vegetation is usually present in the water and along the banks.   Dens are created in banks with interconnecting tunnels and chambers, or, if the water is shallow, they build small lodges similar to the shape of a beavers lodge.

Diet:  Muskrats are primarily vegetarians, but will eat some animal foods.  They feed upon cattail, bulrush, lotus, wild celery, cheatgrass, and sometimes domestic crops.

Breeding information:  Breeding occurs year round except for winter.   Females can produce 1-5 litters per year, typically 2-3, with most litters born in the spring.   Litters contain from 1-11 young, but usually 4-7 is most common.   The blind, naked newborns have fur within 1 week and eyes are open in 2 weeks.   Weaning occurs at 3-4 weeks and the young are fully grown at 6 months.

Status in Tennessee:  Common Muskrats are game animals in Tennessee. They can be abundant in some aquatic habitats across the state.

  • Fun Facts:
    As their name suggests Common Muskrats secrete a musky odor, especially strong during the breeding season, which they deposit along trails, on feeding platforms, and on scent posts.
  • Their mouths are able to close behind the incisors allowing them to gnaw on vegetation underwater.

Best places to see in Tennessee: Any slow moving water habitat with vegetation.