SCIENTIFIC NAME Chinchilla lanigera

TAXONOMY PHYLUM: Chordata CLASS: Mammalia ORDER: Rodentia FAMILY: Chinchillidae

Physical description

Credit: Kim Caesar/Nature Publishing Group

The long-tailed chinchilla is a South American rodent slightly larger and more robust than a ground squirrel, with an average body length of about 12–14 in and average body weight of 400–600 g. Chinchillas have compact, stocky bodies with comparatively thin, delicate limbs. Their heads are relatively large, with prominent, rounded ears. They are native to the Andes Mountains, where they inhabit burrows or rock crevices at high altitudes. Chinchillas are crepuscular, or most active at dawn and dusk, and are agile jumpers, leaping up to 6 ft.

Chinchillas' long, thick fur, which ranges in color from gray to bluish gray or pearl, insulates them in the cold mountains. But it also has its drawbacks: because their fur is so soft, they have been hunted extensively in the wild. They avoid getting wet because the dense fur hinders drying and increases susceptibility to fungus growth. They keep their fur clean by taking dust baths instead. Their full coats also cause them to overheat easily. If chinchillas are restrained or handled roughly, they may struggle or attempt to escape, which can result in 'fur slip,' a phenomenon in which a patch of hair is shed abruptly without damaging the underlying skin.

Research résumé

Chinchillas have served as animal models for investigating the pathology and treatment of both Chagas disease1 and cholera2. But they are most commonly used in auditory research, in part because of the similarity between human and chinchilla hearing anatomy and sensitivity3. The chinchilla has a sizeable middle ear with large auditory bullae and a conductive apparatus similar to that in humans. The chinchilla's hearing range is also similar to that of humans, and chinchillas suffer from presbycusis, or age-related hearing loss, like humans do4. Use of the chinchilla in auditory research is also facilitated by the accessibility of its middle and inner ear for experimental purposes3. Studies on noise-induced hearing loss5, otitis media6,7 and tympanic membrane perforation8 have all used chinchillas. In a recent example, scientists found that conductive hearing loss secondary to fluid collection behind the tympanic membrane in otitis media results largely from impaired mobility of the tympanic membrane in chinchillas9. Other recent findings showed that pretreatment with D-methionine could protect chinchillas against noise-induced hearing loss10.