VISCACHA

any member of two genera of South American rodents belonging to the family Chinchillidae (order Rodentia), found in rocky, mountainous country (mountain viscacha) or on the Argentine pampas (plains viscacha). Mountain viscachas, or mountain chinchillas (Lagidium), are large eared, rabbitlike, and about 35 cm (13.5 inches) long excluding the black, 25-centimetre tail. The soft fur, which is mixed with wool and used for yarn, is tan or grayish, often with a black middorsal stripe. These viscachas are diurnal and gregarious and shelter in burrows or crevices. They are agile and feed on plants. Litters, usually of one young, are born two or three times a year; gestation is about three months. Plains viscachas (Lagostomus maximus) are colonial and live in extensive burrow systems (vizcacheras) characterized by refuse, stones, and other objects piled by the animals around the entrances. Plains viscachas are coarse haired, blunt headed, and gray with black and white stripes across the face. They are about 50 cm (20 inches) long, excluding the 10-centimetre tail. There are usually two young per litter; gestation takes about four months. Agile and fast, plains viscachas are considered pests because of their burrowing and because they feed on grasses needed for domestic animals.