Ondatra zibethicus Linnaeus, 1766
Family : Cricetidae
Common names: Muskrat [En], Rat musqué, rat d’Amérique [Fr], Muskusrat [Nl], Bisamratte [De], Topo muschiato [It], Rata almizclera [Es], Misk sıçanı [Tu]
Braine-le-Comte, HAINAUT ● Belgium
Description: The muskrat is a medium-sized semiaquatic rodent, about 40–70 cm long (half of that is the tail).
Muskrats are covered with short, thick fur which is medium to dark brown or black in color, with the belly a bit lighter (countershaded); as the age increases, it turns a partly gray in color. The fur has two layers, which helps protect them from the cold water. They have long tails covered with scales rather than hair, and to aid them in swimming, are slightly flattened vertically, which is a shape that is unique to them. When they walk on land, their tails drag on the ground, which makes their tracks easy to recognize.
Biology: Muskrats spend much of their time in the water and are well suited for their semiaquatic life. They can swim under water for 12 to 17 minutes. Their bodies, like those of seals and whales, are less sensitive to the buildup of carbon dioxide than those of most other mammals. They can close off their ears to keep the water out. Their hind feet are semiwebbed, although in swimming, their tails are their main means of propulsion.
Muskrats are most active at night or near dawn and dusk. They feed on cattails and other aquatic vegetation. They do not store food for the winter, but sometimes eat the insides of their push-ups. Plant materials compose about 95% of their diets, but they also eat small animals, such as freshwater mussels, frogs, crayfish, fish, and small turtles.
Muskrats normally live in groups consisting of a male and female pair and their young. During the spring, they often fight with other muskrats over territory and potential mates. Many are injured or killed in these fights. Muskrat families build nests to protect themselves and their young from cold and predators. In streams, ponds, or lakes, muskrats burrow into the bank with an underwater entrance. In marshes, push-ups are constructed from vegetation and mud. Muskrats also build feeding platforms in wetlands.
Muskrats, like most rodents, 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. In southern environments, young muskrats mature in six months, while in colder northern environments, it takes about a year. Muskrat populations appear to go through a regular pattern of rise and dramatic decline spread over a six- to 10-year period. Some other rodents, including famously the muskrat's close relatives the lemmings, go through the same type of population changes.
Habitat: They mostly inhabit wetlands, areas in or near saline and freshwater wetlands, rivers, lakes, or ponds.
Distribution: Muskrats are found over most of Canada and the United States and a small part of northern Mexico. They were introduced to Europe in the beginning of the 20th century and have become an invasive species in northwestern Europe. In some European countries, such as Belgium, France, and the Netherlands, the muskrat is considered an invasive pest, as its burrowing damages the dikes and levees. Muskrats also eat corn and other farm and garden crops growing near water bodies.
Interesting video of the Muskrat by Christophe Feliciaggi