Thursday, April 14, 2011

Muskrat---Missouri's little water rodent

This adorable little swimming creature is a muskrat (Ondatra zibethicus). These medium sized rodents are found in all manner of aquatic habitats, including wetlands, ponds, and lakes. Squaw Creek National Wildlife Refuge has hundreds of these little muskrats swimming around the wetlands. They are closely related to voles and lemmings. Their common name comes from two special scent glands located near the tail that are capable of giving off a strong musky odor. They are also related to Beavers, and share the same habitat, but are easily differentiated by their much smaller size. Muskrats weigh up to 4 pounds and can grow to be approximately 24 inches in length, half of that will be tail length. Muskrats are covered in two layers of dense, short fur. The double layer of fur helps them stay insulated in the cold water. Their tails are long, hairless, covered in scales and flattened vertically to help them maneuver as they are swimming. They drag their tails behind them as they walk on land making them easy to track.

They are comfortable walking on land as much as they are swimming in their aquatic habitat. In the water they can dive and spend up to 17 minutes underwater. They close off their ears to keep water from getting in them. They do have hind feet that are somewhat webbed which helps them swim, but their tail is the main means of propulsion.
Muskrats are very common all across the United States, Canada and parts of Northern Mexico. They are however absent from Florida where the Round-Tailed Muskrat is found instead.

Muskrats continue to thrive even though much of their wetland habitats have been destroyed, this is large part due to the fact that new habitats are created in the form construction canals and drainage ditches. They are able to live in areas that are somewhat polluted such as the sulfurous runoff from coal mines. Frogs and other aquatics creatures cannot survive in such areas.

In the spring fighting will break out among males that are fighting for females or defending territories. Some of these fights can be severe and often they are injured or even killed. The two pictured here were chasing each other. I somehow think this was a male chasing and pursuing a female. She wasn't having any of it though. She swam away, and when he gained ground on her she would turn on him and snip at him. Gives new meaning to the term "muskrat love"! Once a mate is located they will remain together and rear their young.

Muskrat families build nests to protect themselves and the young from cold and predators. In streams, ponds or lakes, muskrats burrow into the bank with an underwater entrance. These entrances are 6 to 8 inches wide. In marshes, lodges are constructed from vegetation and mud. These lodges are up to three feet in height. In snowy areas they keep the openings to their lodges closed by plugging them with vegetation which they replace every day. Some muskrat lodges are swept away in spring floods and have to be replaced each year. Muskrats also build feeding platforms in wetlands. Muskrats help maintain open areas in marshes, which helps to provide habitat for aquatic birds.

(Muskrat lodges at Squaw Creek NWR)

Muskrats are most active in the evening or early morning. They can be found feeding on cattails, and other aquatic vegetation. It is reported that they do not store food for the winter, but instead feed on the insides of their lodges when they are unable to get out and swim to seek food. They also share a somewhat harmonious relationship with local beavers and may raid their food stores. Although nearly 100% of their diet is vegetation, they may on occasion eat mussels, frogs,fish, crawfish, and small turtles. Muskrats create trails that they travel to and from the water, these trails are even visible under frozen water. It is these travel pathways that trappers will set their traps to capture these little furbearers. 

Muskrat fur is warm, and the trapping of muskrats for their fur became an important industry in the early Twentieth Century. At that time muskrats were introduced to Europe as a fur resource. Muskrat fur becomes prime at the beginning of December in most northern states. Muskrat fur was specially trimmed and dyed and called "hudson seal" fur, and sold widely in the United States in the early twentieth century. They spread throughout northern Europe and Asia.

Some European countries such as Belgium and the Netherlands consider the muskrat to be a pest that must be exterminated. Therefore the animal is trapped and hunted to keep the population down. The muskrat is considered a pest because its burrowing causes damage to the dikes and levees that these low-lying countries depend on for protection from flooding. Muskrats also sometimes eat corn and other farm and garden crops.

Some people eat muskrat meat and claim it tastes like duck (at least they didn't say chicken). In Detroit it has been ruled by the Archdiocese that muskrat can be eaten during lent in place of fish as they live in water same as fish, so therefore is considered the equivalent to fish. 

Native Americas considered the muskrat a predictor of the upcoming winter weather. They would watch the muskrat and his autumn activities. If the muskrats built mounds early and much larger, then the winter could be expected to be severe. In some Native American folklore it was the muskrat that dove under the primordial seas and returned with the mud that created the Earth, after other animals had tried and failed.  

Muskrats are an important part of any ecosystem as they provide necessary nutrition to other animals in their environment, including mink, bobcats, lynx, fox, coyote, bears, eagles, alligators, wolves and snakes. Even otters, and snapping turtles may prey on the young muskrats if they can catch them. 

These little water rodents are a pleasure to watch and visiting any nearby wetland should yield numerous muskrats to enjoy.


  1. You forgot to mention the state critters in your side menu, like the chiggers and recluse spiders. I've had upclose encounters with both of those! :)

  2. Some of Missouri's smallest creatures are certainly some of the most annoying. I have an additional blog that is all about Missouri Insects and other Inverts.
    I have a blog post on that site about Brown Recluse, just do a search and you should find it. I have not posted about chiggers yet, but perhaps I should giving the fact that spring is here and soon it will be chigger season.

  3. My tomatoes kept disappearing and I assumed it was squirrels until I saw a muskrat with it's beautiful coat shining in the sun. Tried to get a picture but he saw me and ran. He was sitting on his haunches eating and enjoying.

  4. I've never heard of muskrats raiding a garden and eating tomatoes. I am wondering if you have a friendly groundhog. They absolutely love tomatoes and frequently raid gardens to get them.