Reflections in Nature: The muskrat is the little brother of the beaver
Our beaver was the topic of last week’s article, and this week I am writing about one of our wild rats (ondatra zibethica), the common muskrat. Muskrats are rodents related to mice, voles, beavers and rats.
The muskrat is possibly Pennsylvania’s No. 1 furbearer and the nation’s No. 1 fur animal. The muskrat is very important in the fur industry in Canada, where it is known as the Hudson seal.
The muskrat is just what its name implies: a rat with a musky odor. The odor or musk is supplied by two glands, which are located at the base of the tail. The musky odor is used by the animal for communication, especially during the breeding season.
The muskrat’s tail is long (eight to 12 inches), flattened vertically, scaly and partially hairless. The tail serves as a rudder when the animal is swimming and is used to help the muskrat propel itself through the water.
However, it’s the hind feet, which are partially webbed, that produce most of the animal’s movement in the water. The hind feet make good mud shoes that help the animal from sinking in the many mudflats found throughout its preferred habitat.
The muskrat is often referred to as the little brother of the beaver because it has many of the beaver’s features, such as thick, waterproof fur; ability to open its mouth underwater without taking in a mouthful of water; eye, and ear valves that close automatically when the animal dives underwater. However, unlike a beaver, a muskrat neither cuts down trees nor builds dams.
If you want to see a muskrat, visit a pond, where there is much vegetation, or a swamp. Be sure to be at the pond or swamp just before dusk or dawn. This seems to be when the muskrats are most active.
For a den, the muskrat prefers to burrow into stream banks. The hole starts below the water line and then turns upward. An enlargement is made for living quarters, which are lined with a thick bed of leaves. In marsh areas where banks are not available, the muskrat will build a house out of cattails and mud.
This house — known as a pushup — is nothing more than a solid pile of grass, cattails, and mud. The whole structure is built above the water line, with a tunnel dug underground that leads into this haycock house, and a room is hollowed out. In early winter muskrats also create push-ups by chewing holes in the newly formed ice and covering it with a mound of mud and plant debris.
These mounds are often three feet in height and up to 90 meters (300 feet) from the main lodge.
The muskrat will also make channels or swimming lanes through the marsh. These swimming lanes are used by the muskrat to move about the swamp.
The muskrat eats all types of vegetation, however, cattails and arrowhead roots seem to be their favorite. Occasionally, muskrats will eat freshwater clams, fish, and other habitants. They will take their food to a convenient feeding station to eat. This eating station, which is just large enough for one animal, could be under overhanging banks or in a pushed-up mound of cattails.
Occasionally, during the summer months, a rat can be seen feeding while sitting on a log or bank. However, a muskrat’s main defense is concealment. Its main enemies are the mink, weasel, and the great- horned owl. Since these animals are crafty hunters, the muskrat must be an expert at concealment.
Although I mentioned that the muskrat is our most important fur bearer, the word muskrat sounds unattractive for such a desired fur. This is why the furriers dye the pelts and masquerade them under the trade name Hudson seal. The fur is usually dyed black, which produces a warm and beautiful coat.
I have been told many times that the meat of the muskrat is sweet and tender. I doubt whether I have ever tasted muskrat, but I have eaten beaver, which was quite tasty. When ordering off a menu I am uncertain as to how many would order muskrat, however marsh rabbit or Maryland terrapin sounds quite good.
Muskrats are prolific animals.
As many as five litters per year in southern Pennsylvania and four litters in northern Pennsylvania are born. There are 5-8 young per litter, and these young either leave or are driven off after only one month. The young will not reproduce until the following year. The average life span is under twelve months, however, some rats do make it to the ripe old age of five years.
The population seems to have a cycle, with a peak approximately every ten years.
Males mate with as many females as possible and do not assist in raising the young. Although droughts and hard winters take their toll on the muskrat population, flooding during the breeding season is the most destructive.
Flooding kills many of the young muskrats before they have a chance to leave home.
Bill Bower is a retired Pennsylvania Game Commission Wildlife Officer. Read his blog and listen to his podcasts on the outdoors at www.onemaningreen.com.