The long-tailed chinchilla is a rodent species. They have very thick fur with up to 60 hairs growing from a single follicle! Their fur ranges in colour from greys to light browns, with their fronts lighter than their backs. The tip of each hair is usually black. Their hind legs are powerful, enabling them to jump and run effectively in their rocky habitat.
Long-tailed chinchillas are most active at dawn and dusk. They live in large colonies of up to a hundred animals. Females are dominant, but are only aggressive when breeding and even then they rarely fight. They threaten each other by growling, teeth chattering and urinating.
Chinchillas usually form stable bonds for breeding and will have two litters per year. The offspring are well developed at birth, with fur already grown and eyes open. They are weaned within eight weeks. They are sexually mature at eight months old.
Chinchillas eat mainly grasses and seeds with some other plant material. They will also eat insects and eggs if available.
Chinchillas are classified as Critically Endangered by the IUCN despite being a common pet species. The numbers of wild chinchillas have been reduced by more than 90% in the last 15 years. The remaining populations are still declining but are now protected. There is still competition with grazing livestock and habitat destruction for mining and fuel wood. Historically, large numbers were hunted for their fur or for the pet trade.