More interesting differences between beavers and nutria

Importance to nature

Beavers are landscape designers who make significant changes to their environment. By damming water, they create new habitats for many species of plants and animals, increasing biodiversity many times over in areas where they live. 

Nutria are not important for the ecosystem and biodiversity. Their burrows endanger dykes and river banks, threatening flood protection. 

 

Protected status

Beavers are strictly protected under the German Federal Nature Conservation Act. 

Nutria may be hunted throughout the year. 

 

Territorial behaviour:

Beavers are very territorial and will aggressively defend their territory against intruders. 

Nutria are less territorial and often live in larger groups. 

 

Dam building

Beavers build dams to regulate the depth of the water. This must be at least 60 cm. 

Nutria do not build dams. 

 

Homebuilding

There are three types of beaver den: underground burrow, roofed burrow and lodge. 

They all have an entrance that is below the water level. 

The beaver usually has only one den. 

Nutria dig simple tunnels and burrows along the banks of rivers, lakes and marshes. These burrows usually have one or more entrances, which may be above or just below the water level. Nutrias constantly dig new tunnels and burrows. 

 

Activity

Beavers are primarily nocturnal. They spend most of their time building and maintaining their dams and lodges, and foraging for food. 

They are very shy and will dive into the water if they are disturbed. 

Nutrias are active at dusk and during the night. However, they can often be seen during the day. They spend a lot of time in the water and on the banks looking for food. 

They are not very shy. 

 

Food

Beavers are pure herbivores. Their diet consists mainly of tree bark, twigs, leaves and aquatic plants. They prefer soft woods such as willow. 

In winter they cut down trees for the nutrient-rich bark and cambium. They store branches under water outside their burrow for the winter. 

Nutria also eat plants. They also eat snails, worms and freshwater mussels. 

 

Habitat

Beavers prefer freshwater habitats like rivers, lakes, ponds and wetlands where they can create stable water levels by building dams. 

Their habitats are significantly altered by their dams and canals. These affect water levels and the ecosystem. 

Nutria live in similar habitats to beavers. However, they are less selective. They also live in canals, ditches and agricultural irrigation systems. 

 

Family life

Beavers are monogamous and mate for life. 

Nutria are polygamous and do not form permanent pair-bonds. 

Beavers give birth to 2−4 kits once a year, which are born in the den. They also spend the first few weeks of their lives there. Both parents and older siblings help to raise young. 

Nutria have several litters a year, often with 5−7 kits. The female nutria raises its young alone. 

Young beavers stay with their parents for about two years, learning how to build dams and lodges and how to forage for food. They then have to leave their parents' territory. 

Beavers become sexually mature at the age of 2−3 years.

Nutria kits are independent within a few weeks and soon leave their mother to survive on their own. They become sexually mature at five months.