By Michael E. Sievering, Wildlife Biologist
A variety of animals live in Alabama’s lakes, streams, and wetlands. Shorebirds, waterfowl, snakes, turtles, and a number of mammals call this habitat home. Several species of aquatic rodents dwell in aquatic habitats. The most common is the beaver. Another lesser-known species is Alabama’s “little beaver” – themuskrat.
Muskrats (Ondatra zibethicus) are also known as marsh hares. Their name is derived from the musky odor this small mammal emits. Trappers across the country simply term these animals “rats.” Typically the size of a small rabbit (2 pounds), the muskrat’s rich brown fur consists of an outer layer of guard hairs and a thick soft layer of under fur. This under coat acts as insulation, which protects the animal from extreme cold.
This animal also possesses numerous specialized features. Unlike a beaver that has a flattened tail, the muskrat’s tail is laterally flattened. Usually 8-10 inches in length, this tail can actually be used as a rudder or be used to propel the animal through water.
Additionally, muskrats have specially adapted eyes, nose, and a respiratory system that allows them to remain underwater for up to 15 minutes. This is particularly useful when searching for food or avoiding predators.
Like the beavers, muskrats live in dens located in association with local wetlands. Muskrat dens are of two types: the bank den and the hut. Huts are composed of vegetation that can be as high as 3 feet and as wide as 4 feet across. A casual observer of this structure may think it is a beaver lodge. One of the easiest methods used to determine the difference is to notice what construction materials are used. Beavers utilize woody vegetation (sticks, etc.) for lodge construction while muskrats primarily use herbaceous vegetation for “hut” construction. Bank dens are usually located in streams or ponds where water levels are fairly deep and the banks are steep.
Muskrat burrowing can have negative consequences. It can lead to the creation of hazardous terrain for local livestock. It can also be responsible for dam failure or cave-in associated with ponds and lakes.
Muskrats are statewide in distribution but seem to be much more common in north Alabama, especially in the Tennessee Valley.