Long-tailed chinchillas have long hair, with gray, white, and black bands; it is silky, extremely soft, and firmly adhered to the skin. The general color of their upper parts is bluish or silvery gray; the underparts are yellowish-white. The tail has long, coarse, gray and black hairs on its dorsal surface. Domesticated animals are larger than wild ones, with females being larger than males.
Long-tailed chinchillas are found in the mountains of northern Chile. They occur in Aucó, near Illapel, IV Región, Chile, in Reserva Nacional Las Chinchillas and in La Higuera, north of Coquimbo. These chinchillas were reported from Talca, Chile, reaching north to Peru and eastward from Chilean coastal hills throughout low mountains. They inhabit barren, arid, and rugged areas of the mountain chains. Long-tailed chinchillas occur in rocky or sandy areas with a sparse cover of thorn shrubs, few herbs and forbs, and scattered cacti.
Long-tailed chinchillas are social animals. They live in colonies of more than 100 individuals. They are primarily nocturnal creatures but also can be seen on sunny days sitting in front of their hole, climbing and jumping on the rocks. Female in this species are dominant. They are very aggressive towards males and other females during the breeding time. When threatened Long-tailed chinchillas growl, chatter their teeth, and urinate.
Female Long-tailed chinchillas are mostly monogamous. This means that they have only one mate during the breeding season. In the wild, they breed between October and December. Females usually have two litters per year, with 2-3 kits per litter. Gestation lasts around 111 days. Young are born well developed, fully furred, and have their eyes open. Females nurse their kits for 6-8 weeks. Long-tailed chinchillas become reproductively mature after 8 months of age.
Long-tailed chinchillas have been threatened for years by poaching, pet trade, hunting, mining, and firewood extraction. They also suffer from predation by foxes and owls, and compete with grazers such as goats and cattle. Additionally, these animals may be threatened by El Niño events ( a climate cycle in the Pacific Ocean that has a global impact on weather patterns).
According to the IUCN Red List, the total population size of Long-tailed chinchillas is around 5,350 mature individuals. This species’ numbers are decreasing and it is currently classified as Endangered (EN) on the IUCN Red List.