Environment | ANIMAL TRACKER


by Rowan Hooper

* Japanese name: Nutoria
* Scientific name: Myocastor coypus
* Description: The nutria, also called coypu, is a ratlike mammal with a long tail and broad, orange teeth. It has small eyes and ears, short legs and webbed hind feet that are much longer than the fore feet. The hind feet have five digits and the fourth is unwebbed; the fore feet have four long digits and a tiny thumb. The length of the triangular-shaped head and body is between 47.2 cm-57.5 cm, with the tail adding about 37.5 cm. Nutria weigh between 5 kg to 10 kg. The fur is of two types: soft, dense underfur (a gray color) and coarse top fur (yellowish- to reddish-brown). Females have four pairs of mammary glands on the sides of the body, not on the chest as in other mammals.
* Where to find them: These rodents are native to South America, but after escaping from fur farms, they colonized most of the world, including Japan. Completely at home in water, they can be seen in wetland areas from Honshu to Kyushu.
* Food: Freshwater vegetation. The nutria is a herbivore and will eat plant stems, leaves, roots and bark. It will also eat rice plants from paddies.
* Special features: Nutria become sexually mature when only six months old and may live for six years; they have 1-13 babies per litter that are born fully furred. They usually breed three times a year. Their fast maturation and sometimes destructive feeding habits have led scientists to list the nutria as one of the world’s 100 most dangerous alien species. Nutria dig burrows to live in, and these and their habit of eating plant roots can contribute to erosion, as well as destroy vegetation that other animals and birds depend on.