The muskrat considered by Native Americans to be an important animal in the creation of the earth. As told in the mythological story “The Earth on Turtle’s Back” – ” I have heard there is Earth far below the waters…So the birds and animals decided someone would have to bring up Earth. One by one they tried” …but all failed “She was not as strong or as swift as the others, but she was determined.” She swam deeper and deeper until Muskrat finally grasped at the bottom, bringing a tiny bit of Earth that she placed on the back of the Turtle. “Almost immediately it began to grow larger and larger and larger until it became the whole world.”
The muskrat, Ondatra zibethicus, is a semi-aquatic mammal. It is much smaller than a beaver with a body 10-14″, tail 8-11″ and weighing only 2-4 lbs. They have very large heads, small eyes and their ears are almost invisible under the fur. They have poor senses of smell, hearing and sight. Their tail is also much different than a beaver’s being long, rat-like, scaled and vertically flattened (from side to side). Although the tail is narrow they will slap it on the water as a warning signal. Muskrats are good swimmers, using their large, slightly webbed feet to propel them through the water at up to 3 miles per hour with their tail used as a rudder. They can even swim backwards. Their dense, reddish-brown to dark brown fur is waterproof and the underfur traps air for both buoyancy and insulation. Like the beaver it has adapted to chew underwater by having lips that close behind the front incisors.
Muskrats are found throughout most of Canada and the United States and into northern Mexico. They were introduced to Europe at the beginning of the 20th century for their fur, but are considered in many areas to be invasive and a nuisance due to the damage being caused by burrowing in dikes and levees.
Muskrats inhabit wetland areas including riparian zones, on the banks of rivers or steams, in marshes and along the edges of ponds and lakes. Muskrats appear to favor marshes where the water is 4-6 ft. deep. They will burrow into a bank with a 6-8″ underwater entrance. Their dens have dry chambers, underwater tunnels and ventilation holes. They have lodges, 2-3 feet tall, constructed of aquatic plants, brush and mud that are often built on top of a good base such as a tree stump. They also construct less complex feeding huts or feeding platforms where when eating they are protected from predators and bad weather. Their predators include mink, foxes, coyotes, bobcats, snakes and birds of prey. They are crepuscular, active at dawn and dusk and at night, year round. They have a special adaptation known as “heterothermia”, by regulating the flow of blood to their extremities it allows the feet and tail to be cooler than the body core temperature. They also have the ability to remain underwater for up to 20 minutes.
Like most rodents they are prolific breeders with 2-3 litters/year and 6-8 babies, known as kits, per litter. At 30 days the kits can eat, swim, dive and feed themselves. Feeding on 95% plant material like cattails, cordgrass and bulrush, they also eat mussels, frogs, crayfish, fish and small turtles. Fully grown at 6 weeks, they remain with the female for about 6 months. They live in large family groups, but if the den becomes overcrowded the female will kick-out the young.
With a relatively small home range of about 200 ft. in diameter they are territorial and will mark their area with musk. They got their name because they secrete this musky odor and because they look like a rat. Although they are aggressive towards other muskrats for territory and mates they have been known to share a beaver’s lodge and act cooperatively.
The book Muskrat Will Be Swimming is beautifully written by Cheryl Savageau and illustrated by Robert Hynes. It uses the creation story “The Earth on Turtle’s Back” to provide a lesson on knowing who you are and staying strong in the face of hurtful criticism.
The Earth on Turtle’s Back
Muskrat Will Be Swimming by Cheryl Savageau
Wildlife Fact Sheet – Muskrat
Nature Serve Explorer – Muskrat
Animal Diversity Web – Muskrat