Muskrat (Ondatra zibethicus)
(Photo by Linda Tanner)
In The Wild
The muskrat is a medium sized semi-aquatic rodent with webbed hind feet and a flat tail – which it uses as a rudder.
Despite its name, the muskrat is not a ‘true’ rat but is a large member of the family of voles and lemmings. The name comes from the musky odour that comes from gland secretions from the perineal area.
It usually has a dark brown or red brown coat. They are well adapted to swimming and to cope with the demands of living in a wetland habitat: it is found in fresh and salt water marshes, lakes, ponds and rivers. The head and body length of the muskrat is between 229-325mm, with a tail length of 180-295mm. They weigh between 681 to 1816 grams.
It is a native species to North America but now can be found in many other parts of the world after being introduced across much of South America, Europe and parts of Asia. They can have a sizeable impact on local ecosystems.
They normally live in family groups, with a pair (male and female) and their offspring. They appear to be mostly monogamous and when spring arrives they become very territorial and will fight bitterly over territory and potential mates. When unexpectedly disturbed, the muskrat will utter a whinish growl.
Muskrat families take great care over the maintenance of their nests which are built to protect themselves and their young from cold and predators.
In streams or large ponds, muskrats will burrow into the bank and create an underwater entrance. In marshes, raised nests are built using vegetation and mud. In snowy areas, the entrances to these constructions are plugged with vegetation, which they replace every day. Muskrats also build feeding platforms in wetlands. They help maintain open areas in marshes, providing valuable habitat for many species of birds and mammals.
Generally, muskrats are largely nocturnal and crepuscular (active at dawn and dusk), but they are occasionally seen in the day during winter. They feed mostly on a range of vegetation with a particular fondness for the cattails plant. They do not store food for the winter and have been observed taking food stored by beavers and the two species appear to often share shelter and food stores.
Plant materials make up about 95% of their diet but they also take small animals including fish, mussels, frogs, crayfish and small turtles. Muskrats follow trails they make in swamps and ponds and when the water freezes, they are able to continue following their trails under the ice.
Muskrats are themselves heavily predated. As part of the ecosystem, they provide an important food resource for many species including mink, foxes, coyotes, wolves, lynx, bears, eagles, snakes, and larger hawks and owls.
In common with most rodents, muskrats are prolific breeders. Females can have two or three litters a year of six to eight young each. The babies are born small and hairless, and weigh only about 22 g. Development of maturity in the youngster varies according to the climate with animals in colder areas taking longer. The populations appear to go through a regular patterns of rise and dramatic decline spread over a six to 10 year period. Muskrats will live for up to 3 years in the wild and up to 10 years in captivity.
Muskrat and the Fur Trade
The Muskrat’s fur is thick, glossy and durable making it a target for fur trappers. Tens of millions of them have been trapped over the last 100 years. At the beginning of the twentieth century, the species began to be farmed across much of Europe and parts of Asia. This saw numerous escapes or releases, populations which became naturalised and are still present today.
A population became established in the UK, but great efforts were taken to eradicate it and it is one of the few ‘introduced’ species in Britain that has been successfully eradicated.
Today, the North American Fur Auctions report that muskrat pelt remain popular – along with coyote- largely due to consistently strong sales in Korea.
Most of the muskrat pelts around today come from animals that have been trapped. Trappers commonly use ‘drowning sets’- where traps are set in a way designed to drown and the muskrats and other semi-aquatic mammals like mink and beaver caught in them. These are set along the water’s edge.
Thomas Eveland’s ‘Jaws of Steel’ (1991) states: “the muskrat flounders about on the surface until exhaustion and the weight of the trap overcome it – and then it drowns. … Drowning an animal by clamping a steel trap to its leg is anything but humane..”
Muskrats can take up to five minutes drown in these traps. The fur trade’s use of muskrat fur is truly cruel and it is shameful that such cruelty continues in the 21st Century.
[Below: In 2011, Respect for Animals conducted an undercover investigation into trapping in the US. Pictured is a dead muskrat which had suffered horrific injuries to its tail]