Systematic classification and distribution
Native to South America, nutria, Myocastor coypus (Molina, 1782), it naturalized in many parts of Europe, including Italy, where it escaped captivity after being introduced for industrial purposes for the use of furs (Castorino fur). In areas where there is a shortage of predators (wolf, fox, marten, wild cat, lynx, stray dogs, several birds of prey, and large predatory fish such as pike and catfish) the uncontrolled growth of this species can cause damage to agricultural crops .
Nutria or Castorino (photo Alessandro Cerofolini)
Nutria (photo Vinicio Sforzi)
The nutria has a long scaly cylindrical tail with few hairs; the coat is generally brown, dark or golden, but there are also specimens with isabella or cream coat.
The ears are small and the incisors, orange in color, are large and protruding; it has long silver mustaches. The hind limbs are parmati and the breasts in the females are in latero-dorsal position, typical of aquatic animals that raise offspring in water.
It can reach a length of 50-60 cm in adult males (tail excluded) and a weight of 7-9 kg.
The females mate all year round and give birth twice (2-4 young), after about 130 days of gestation. After about a day the nutria babies are able to follow the mother and, after three or four weeks, they feed on their own. Sexual maturity is reached at just two months. Mortality during the winter period is high in cold climate zones. The nutria prefer the river or marsh areas, where they feed on aquatic plants and algae and, during the winter, also on tubers, rhizomes and roots. In Italy, the populations living in the lowland areas of the north also explore the fields surrounding the waterways (feeding on some crops such as corn and sugar beet), while in the center-south they live almost exclusively in the riverbeds and along the banks.