Nutria Aveyron

The nutria inhabits slow-flowing and standing freshwater bodies such as rivers, streams, canals, ditches, ponds and oxbow lakes with rich aquatic and bank vegetation and a bank soft enough to dig burrows into. With a head-to-body length of about 43 to 65 centimetres, a round, almost hairless tail roughly 30 to 45 centimetres long and a weight of about 4 to 8 kilograms, it is clearly larger than the muskrat but smaller than the beaver. Distinctive identification features include the prominent, clearly visible ears, the white whiskers on the muzzle and the strikingly orange incisors. When swimming, the nutria holds its head at an upward angle out of the water so that the back usually remains visible.

Originally native to South America, the nutria was imported to Europe in the late 19th century for fur and meat production. From animals that escaped or were released, free-living populations have developed since the 1930s and today occur across all German federal states and large parts of Central Europe. With two to three litters per year and an average of five young per litter, the species reproduces quickly and can build up populations rapidly in suitable waters. Because the species is now widespread, EU Regulation 1143/2014 sets population control rather than eradication as the management goal in Germany.

From a water-management perspective, the nutria's underground burrows are the real problem: extensive tunnel systems in bank slopes and dikes lead to destabilisation, subsidence and, in the worst case, dike failure during flooding. There is also damage to agricultural crops, reed beds and the breeding and shelter habitat of waterbirds, fish and amphibians, because the nutria grazes bank and aquatic vegetation over large areas. For these reasons, water boards and hunting associations across Germany call for consistent population control.

For reliable identification, comparison with the two confusion species is essential. The strictly protected beaver weighs up to 30 kilograms, is clearly larger and heavier, carries the broad, horizontally flattened paddle tail and has no visible ears or white whiskers. The muskrat, at around 35 centimetres body length, is markedly smaller than the nutria and carries a narrow, laterally flattened rudder tail that it swings sideways in the water. The nutria sits between the two, with its round tail, white whiskers and visible ears.

Hunting practice combines shooting and trapping. The core method is trapping with live traps, usually closed tube traps or wire box traps, because they largely exclude by-catch of the strictly protected otter and other species and are legally required in most German states. Traps are set on the bank, often baited, and depending on state law must be checked at least morning and evening; in many states an additional trapping qualification is required. Captured animals are dispatched in line with animal-welfare rules by gunshot or by heart stab. Shooting is done mainly from a high seat at dusk and at night, in several states with night-vision optics and artificial light. In many regions, bounty payments per tail are offered to support the population control that water management requires. The annual hunting bag in Germany is now in the five-digit range and continues to rise.