The familyChinchillidae is in the orderRodentia and consists of thechinchillas, theviscachas, and theirfossil relatives. This family is restricted to southern and westernSouth America, mostly living in mountainous regions of theAndes, except one species living on plains. They are medium to large-sized rodents, weighing from 800 g (28 oz) to 8 kg (18 lb), with strong hind legs and large ears and a bushy tail. All species have thick, softfur, which is considered valuable in some cultures.[2]
Members of thefamily Chinchillidae are somewhatrabbit orsquirrel-like rodents varying in weight from 0.5 to 8 kilograms (1.1 to 17.6 lb). They have large eyes, medium-sized ears, soft dense fur and short bushy tails. The forelegs are shorter than the hind legs. The forefeet have four toes while the hind feet have four small-clawed toes inLagidium andChinchilla but three large-clawed toes in Lagostomus, a digging species. Theirdental formula is1.0.1.31.0.1.3 and theirincisors grow continually throughout their lives. Chinchillids are generally brownish-grey or grey on the dorsal (upper) surface and pale on the ventral (under) surface. Plains viscachas have distinctive black and white markings on their faces.[3]
The Chinchillidae are native to South America. Chinchillas and mountain viscachas live in remote mountainous regions ofChile andPeru, on rocky surfaces and among boulders. Plains viscachas are found in the plains of Argentina, from theGran Chaco area southwards toPatagonia.[3]
Members of this family areherbivorous and live incolonies of up to several hundred individuals. Plains viscachas live in extensive networks of burrows on plains where it is said that ten viscachas can eat as much as does one sheep. Mountain viscachas and chinchillas live in craggy upland regions where they inhabit crevices among rocks and are skilled climbers. Although they can jump, they mostly move about by walking or running. They use vocalizations to communicate with each other, especially the plains viscachas.[3]
Both species of chinchillas are listed by theIUCN as being "critically endangered" and may be extinct in the wild. They were at one time relatively common but have been overexploited by hunters catching them for thefur trade.[4][5] Theplains viscacha is rated as being of "least concern" as it seems tolerant of habitat disturbance and although some populations have been eliminated locally through pest control measures and hunting, others have expanded into newly cleared areas.[6] Both thenorthern andsouthern mountain viscachas are also considered of "least concern" as they have a wide range and are locally abundant in some areas.[7][8]
Three extant and three fossil genera are currently recognized:
