Ondatra zibethicus
Muskrats are often visible during the day. BPO.
Muskrats are large rodents, about 24–40 cm long, with a powerful, compact and scaly tail 19–27.5 cm long. The Muskrat weighs 0.6–1.8 kg. Dry fur is golden brown above and greyish below.
Muskrats live near water, especially fresh water ponds, pools, lakes, canals, and slow-flowing streams and rivers, but can also be found in brackish water with plentiful vegetation. Muskrats live in family groups, and a couple with offspring will hold a clearly established territory.
Muskrats dig tunnels in embankments and build lodges that resemble those of beavers but are smaller and lack tree branches. The entrance is below water level. The underground tunnels of Muskrats can eventually completely undermine dykes and dams.
Muskrats build lodges resembling those built by beavers. PB.
The animals feed on aquatic plants, especially horsetails, reeds, sedges, and grass, but may also consume snails, crustaceans, and especially mussels. They will also feed on fish left behind by Otters. In winter they eat rhizomes and plant roots. In central Europe the Muskrat also eats crops in gardens and fields.
Muskrats are most active early in the morning and at dusk, but they can be seen anytime during the day if they are not disturbed.
Muskrats were introduced into Europe from North America for the fur trade at the beginning of the twentieth century. In Finland, more than 2,000 individuals were released, and today the animals can be found throughout the country. From Finland they have spread to northern Norway and Sweden. In the rest of Europe, animals that have escaped from fur farms have also established themselves in wild populations in many areas. Around the late 1990s or early 2000s, Muskrats from Germany reached Denmark, and this mammal is now spreading further north.
The Muskrat has five toes with long, sharp claws on both front and hind feet. The little toe on the front foot is so small, you often see the impression of only four toes. The front footprint is 3–3.5 cm long and about 3.5 cm wide. The hind feet have narrow webbing between the toes, and the toes are equipped with stiff hairs that help in swimming and make the print appear wider. The hind footprint is 5–7 cm long and about 5–6 cm wide. On soft terrain, you can often see drag marks of the tail.
A ‘Muskrat highway’ on a lake shore. TT.
Muskrats live along slow-flowing water or by lakes that do not freeze over. They dig long tunnels in river and stream banks and along shorelines. The entrances are always below water level and 15–20 cm in diameter. The tunnels can be up to 6 m long before reaching the actual living quarters.
On calm water, structures might also be built on a floating wooden base. The buildings, resembling small beaver lodges, are constructed from bulrushes, reeds, grass, and earth, and may reach 1.5 m across and a height of 1 m. The entrance is always below water level.
The Muskrat’s scat is dark brown, cylindrical, 1.2 cm wide and about 6 mm thick. In spring it is deposited in mounds on clumps of grass, stones, uprooted or felled trees, tree stumps, etc. The animals may also build mounds with mud and plants and use their scat as a territorial marker; otherwise, you usually see scat in water.
Muskrats also occasionally build nests in an undisturbed place among aquatic plants, where the water is calm.
The Muskrat leaves noticeable tracks in vegetation. On the shore, you come across paths running among plants, and in large, flat, grazed areas you might see chewed-off plant remains in the water. Muskrats will browse a relatively large area.
Muskrats relish river mussels. They press their sharp front teeth into the shells and force the two halves apart. Empty mussel shells prized apart in this manner are easy to find.
Muskrat paths in a marsh.
