Scientifically known as Ondatra zibethicus, the muskrat is a testament to nature’s adaptability and creativity. While it might remind you of a beaver, the muskrat has its own set of unique features and behaviors that make it stand out in the wetland crowd. It is the only species in the genus Ondatra that is still alive today, and there are 16 subspecies across their native range.
These little engineers are native to North America, but also thrive as an introduced species across South America, Europe and Asia. Like the beaver with which they often share habitat, they spend much of their time in the water and have an important role to play in their local ecosystems.
Appearance & Characteristics
While they may look similar to beavers from a distance, Muskrats are actually much smaller and not nearly as heavy. The average Muskrat has a body around 12.5 inches (32 cm) long and they can range anywhere between 8-14 inches (25 cm – 36 cm) generally, excluding the tail. An adult can be expected to weigh anywhere between 1.5 to 4 pounds (0.6-2 kg).
Their flat, scaly tail, can add up to around 9.5 inches to their overall length. It acts like a rudder when they swim, helping them navigate their watery environment.
Muskrats have dense, dark brown fur and it’s not just for show. It traps air, providing insulation in cold waters and aiding buoyancy. This fur changes slightly with the seasons, becoming a tad lighter in the summer.
Despite having quite large heads, they have almost invisible ears, shielded by their fur. They are experts at detecting movements in their waterways by making use of their sensitive, medium-sized whiskers.
Similarly to the beaver, the muskrat has a few physical adaptations that make it particularly agile in the water. One of the most prominent are their big, flipper-like feet. The back ones are slightly webbed, making them very efficient swimmers.
Distribution – Location and Habitat
From the swamps and marshes of the USA and Canada to the Gulf coast and even the Mexican border, muskrats are found right across the North American continent to which they are native. As an introduced species however, they can also be found in parts of Europe and Northern Asia. In some countries in Europe it is now considered an invasive species, and the importation and breeding of the muskrat has been banned here since 2017.
While they can be found in ponds, lakes, and swamps, muskrats have a special relationship with marshes. It is their preferred habitat by far. The constant water level in marshes offers them the stability they need for building homes and manipulating their waterways. They prefer environments that have at least 4 to 6 feet of water.
Similarly to beavers, Muskrats are renowned engineers and architects within the animal kingdom. They build lodges or ‘bank burrows’ using vegetation, often in water depths ranging from 15 to 40 inches. These lodges protect them from predators and the elements and provide a safe place to raise their young. They have also been known to also inhabit abandoned beaver lodges when the opportunity arises.
Lifestyle & Behaviour of Muskrats
Muskrats have some quite complex social dynamics that can change with the season. For most of the year, they prefer solitude or the company of their immediate family only, particularly when resting as an effort to maintain body heat. However, during breeding seasons, they do live in larger family groups, with well defined territorial borders.
The family group will consist of a male, female and their offspring. When you consider that a female can have up to three litters of up to 10 offspring in a summer season, that’s a lot of mouths to feed!
This can sometimes lead to territorial disputes and if a territory becomes too crowded the mother female will kick out her offspring. This makes room for the family to expand again in the next breeding cycle. Males might also fight for breeding right and in territorial disputes.
Muskrats have a rather unique way of communicating. They secrete a musky scent to mark their territory or send messages. They also use a range of vocalisations, particularly squeaks and squeals to express themselves.
While they are known to be active throughout the day, dusk is their prime time. You might say they are diurnal or crepuscular depending on the specific groups behaviour. But dusk is generally when they’re most likely to be seen foraging or playing in the water.
Diet & Nutrition of Muskrats
Muskrats are generally herbivores and the majority of their diet is made up of the roots of aquatic plants. Cattails are a particular favourite and yellow water lilies too. Plant material makes up at least 95% of their diet by all accounts.
There are some sources that suggest however, that muskrats, on occasion show omnivorous behaviour, snacking on small frogs, crayfish and mussels if available in their environment.
Muskrats have a very healthy appetite, and are known to consume about one-third of their weight every day. Their digestive system is specially designed to extract nutrients efficiently from green vegetation.
Predators & Threats to Muskrats
Muskrats can be quite effective at evading predators. They have the ability to dive into water and stay submerged for up to 17 minutes. That’s usually plenty of time for a predator to give up and move on. Despite this, there are lots of predators that enjoy a muskrat snack.
Then there is the human threat. Historically, humans have hunted muskrats for their fur, which was a big industry in North America in some areas for much of the early 20th century. Their meat has also been a source of food in some cultures.
Changes in their wetland habitats, whether due to natural reasons or human intervention, can also pose its own challenges. They’re particularly sensitive to rapid temperature changes. However, despite this they are pretty adaptable animals, and have shown the ability to adapt to new water environments better than some of their competitor species.
From March to August each year, muskrats are in their breeding season. A female muskrat can give birth to two or three litters each year, and each litter can have six to ten young ones.
Gestation lasts for around 28 days and newly born muskrats are tiny and hairless. They are vulnerable and totally dependent on their mothers for the first month. They might be born small but they grow rapidly, becoming independent in an soon as a few months depending on their environment.
Populations in more temperate environments, around the southern states or Mexico ca reach maturity in around 6 months. Populations in the northern extremes of the range though, such as Canada and Scandinavia, can take as long as a year to develop fully.
Lifespan of Muskrats
In the Wild, muskrats live for about 3 years on average. Predation and environmental factors play a role in their relatively short lifespan.
In contrast, when living in controlled environments, like zoos, they can live up to a decade, showing their resilience and adaptability, as well as their potential longevity when external and environmental pressures are removed.
Population and Conservation
Despite the various threats that muskrats face, they have maintained a stable population in many regions. Their adaptability and rapid reproduction rate play a role in this. Muskrats are a key food source for many animals including foxes, coyotes, wolves, raccoons, bears and alligators.
While human pressures have significantly reduced the availability of wetland habitats, muskrats have adapted well to a changing environment and are quick to make use of new irrigation channels and canals.
Currently, experts aren’t overly concerned about their population. They’re listed as a species of ‘least concern‘ by the IUCN and in some areas are classed as invasive – banned from breeding and importing.
5 Fun Muskrat Facts for Kids
- Exceptional Swimmers: Muskrats can swim backwards and can hold their breath underwater for up to 17 minutes!
- Air-trap Fur: Their special fur can trap air, making them float like a boat.
- House Sharing: Sometimes, muskrats live in old beaver homes. Talk about upcycling!
- Big Eaters: Muskrats have a massive appetite for their size and are known to be big eaters. They eat up to a third of their bodyweight every day!
- Legendary Tales: Muskrats have been featured in Native American tales about how the world was created.