Muskrat Must Knows
Drawing of a muskrat from Canva.
Aptly named for their rat-like appearance and strong, musky odor, this week I’d like to talk about a semi-aquatic rodent species commonly inhabiting the waters of Pennsylvania— the Muskrat (Ondatra zibethicus).
Related to rats, mice, voles, and beavers, muskrats resemble a small beaver with a long, scaly, rat-like tail. Adult muskrats only weigh 2-3 pounds and are 22-25 inches long from head to tail. Physiological adaptations allow muskrats to be successful in aquatic and terrestrial environments. Their tail works both as a prop when standing on hind feet and as a rudder and propeller in water. Large, partially-webbed hind feet are helpful for swiftly swimming through water, while small, clawed forefeet are useful for burrowing. An insulating coat, with dense, silky underfur overlapped by long guard hairs, keeps muskrats warm in cold waters. (Muskrats are also the most abundant furbearer in the U.S.)
Found throughout most of North America, muskrats live around slow-moving water bodies such as ponds, marshes, streams, and rivers (occasionally fast-moving). Muskrats build elaborate homes, called huts or lodges, out of mud and vegetation. Lodges can be 8-10 feet long and 2-3 feet above the water. Alternatively, muskrats will build a shelter by burrowing into stream banks, dikes, or dams, often causing damage; however, muskrats don’t dam streams. Their lodges or burrows have above-water living spaces and underwater entrances.
Generally, muskrats eat the roots and stems of aquatic plants, such as cattail, water lilies, and pickerelweed. Fruits, legumes, grains, and grasses are eaten when found around water. Crayfish, fish, frogs, freshwater mussels, and even muskrat carcasses are also fed upon. Since muskrats don’t hibernate, during the winter they will dig roots and shoots from marsh bottoms or feed on the bark, twigs, and buds of trees, such as ash, willows, and cottonwoods. Muskrats actually alter their environment through their diet. By feeding on vegetation, muskrats open up areas of dense vegetation, which can be beneficial for waterfowl and other aquatic wildlife. Although, they may also damage ornamental, agricultural, or garden crops.
Young and immature muskrats are particularly vulnerable as prey to snakes, snapping turtles, foxes, minks, owls, and hawks. Yet, muskrats are quite abundant and proliferate. Optimal habitats (where the best resources are found) are often overpopulated, and these territories are aggressively defended. By failing to breed in overpopulated areas, these populations are able to limit their own numbers. Individuals in less-optimal habitats are taken by trappers, preyed upon, or forced to find a new habitat.
If you would like to read more about muskrats, visit https://www.pgc.pa.gov/Education/WildlifeNotesIndex/Pages/Muskrat.aspx.
Written by Faith Forry — February 10, 2021
