Chinchillidaechinchillas and viscachas


The family Chinchillidae includes 7 currently recognized species divided into two subfamilies: Lagostominae and Chinchillinae. The subfamily Lagostominae includes one genus (Lagostomus) with one extant species: Argentine plains viscachas (Lagostomus maximus). The subfamily Chinchillinae includes two genera: Chinchilla and Lagidium. There are two extant species within the genus Chinchilla: short-tailed chinchillas (Chinchilla chinchilla) and long-tailed chinchillas (Chinchilla lanigera). Within the genus Lagidium there are four extant species: northern mountain viscachas (Lagidium peruanum), southern mountain viscachas (Lagidium viscacia), Wolffsohn’s mountain viscachas (Lagidium wolffsohni), and Ecuadorian mountain viscachas (Lagidium ahuacaense). (Ledesma, et al., 2009; MacDonald, 1984; Nowak, 1991; Nowak and Paradiso, 1983; Rasia, et al., 2021; Wilson and Reeder, 2005)

Geographic Range

Members of the family Chinchillidae are native to the Neotropical region, primarily in the Andes Mountains, including parts of southern Peru, northern Chile, southwestern Bolivia, and western Argentina. However, Argentine plains viscachas live in the Pampas of South America, including central and eastern Argentina, southern Bolivia, and southern Paraguay. (MacDonald, 1984; Wilson and Reeder, 2005)


Chinchillas (genus Chinchilla) and mountain viscachas (genus Lagidium) live in the Andes Mountains at elevations between 3,000 and 5,000 m above sea level (asl). They establish dens in the crevices of rock piles. In contrast, Argentine plains viscacha (Lagostomus maximus) inhabit lower elevation grasslands and desert scrublands in the Pampas of South America, as high as 2,680 m asl. Argentine plains viscachas spend the day in burrows, called vizcacheras, and forage between dusk and dawn. (Branch, 1993; Giulietti and Jackson, 1986; Jackson, et al., 1996; MacDonald, 1984; Nowak, 1991; Nowak and Paradiso, 1983; Puig, et al., 1998; Wilson and Reeder, 2005)

Systematic and Taxonomic History

Chinchillas and viscachas are rodents (order Rodentia). More specifically, they are hystricognaths (infraorder Hystricognathi) within the suborder Hystricomorpha. Within Hystricognathi, they are part of the parvorder Caviomorpha, which includes all New World hystricognaths. The closest relatives of chinchillas and viscachas are chinchilla rats (family Abrocomidae), which are included in a common superfamily, Chinchilloidea. Some researchers previously considered New World hystricognaths to be a polyphyletic group, but current molecular data supports the hypothesis that they are a monophyletic clade, defined as Caviomorpha.

Within the family Chinchillidae, there are two subfamilies: Chinchillinae and Lagostominae. The subfamily Lagostominae includes the genus Lagostomus, with only one extant species. The subfamily Chinchillinae includes the genus Chinchilla, which consists of two extant species, and the genus Lagidium, with 4 extant species. There were previously only three species recognized in the genus Lagidium, but genetic research in 2009 distinguished Ecuadorian mountain viscachas (Lagidium ahuacaense) from northern viscachas (Lagidium peruanum). (Candela and Rasia, 2012; Spotorno, et al., 2004; Wilson and Reeder, 2005)

  • Synonyms
    • Eriomyidae
    • Lagostomidae
    • Viacacidae
    • Viscacciidae
  • Synapomorphies
    • Lophodont
    • Hypsodont
    • Hystricomorphous

Physical Description

Chinchillas and viscachas have thick fur and slender bodies with short forelimbs and long, muscular hindlimbs with fleshy pads on their paws. Members of the genera Lagidium and Chinchilla have finer fur than members of Lagostomus. All members of the family Chinchillidae have four digits on their forefeet, but the number of digits on their hindfeet vary by genus. Members of the genus Lagostomus have three hind digits with powerful claws for digging, whereas members of the genera Lagidium and Chinchilla have four hind digits with comparatively weak claws. Their bodies range in length from approximately 23 to 66 cm, and their tails range in length from 7.5 to 40 cm. Some species in the family Chinchillidae exhibit size-based sexual dimorphism, although which sex is larger depends on the species.

All chinchillas and viscachas have a dental formula of I 1/1, C 0/0, P 1/1, M 3/3. Their teeth are lophodont and hypsodont, which is advantageous considering they eat exclusively plant material. (Nowak, 1991; Nowak and Paradiso, 1983)


The mating systems of species in the family Chinchillidae vary depending on genus, although they generally exhibit polygyny. In the genus Lagostomus, males often display increased aggression towards other males and disperse from the main colony when young are born. In the genus Lagidium, females become more aggressive while in estrus and drive males out of burrows. In the genus Chinchilla, females are highly aggressive towards other females and males throughout the year and will threaten conspecifics with behaviors such as chattering, urinating, and growling. All members of this family use vocalizations for communication, but physical fights between males during the breeding season is only reported in the genus Lagostomus. (Nowak, 1991; Nowak and Paradiso, 1983)

In wild populations of chinchillas and viscachas, females undergo seasonal estrus cycles. However, some species are capable of breeding throughout the year in captivity. Some species in the family Chinchillidae experience postpartum estrus, and post-lactation estrus is common in the genus Lagostomus. The estrus cycle is an average of 38 days long in chinchillas (genus Chinchilla), 57 days long in mountain viscachas (genus Lagidium), and 45 days long in plains viscachas (genus Lagostomus). The timing of the breeding season varies for distinct populations within species. The average age of sexual maturity is 8 months for chinchillas, 1 year for mountain viscachas, and 8.5 months for female plains viscachas, and 15 months for male plains viscachas. There are some claims that chinchillas are monogamous, but there is currently little evidence to support this claim. (Nowak, 1991; Nowak and Paradiso, 1983)

All members of the family Chinchillidae give birth to small litters of young, although average litter size varies between genera. Mountain viscachas (genus Lagidium) have an average of 1 young per litter, whereas plains viscachas (genus Lagostomus) have an average of 2 (range 1 to 4), and chinchillas (genus Chinchilla) have an average of 2 or 3 (range 1 to 6). Offspring are precocial, and newborn mountain viscachas are even capable of eating solid foods.

Average gestation period is 111 days for chinchillas , 140 days for mountain viscachas , and 154 days for plains viscachas. Average weaning time for all members of the family Chinchillidae is typically around 8 weeks. Some species are capable of producing multiple litters per year, given favorable conditions. Both chinchillas and viscachas are social and live in colonies, so offspring typically end up living with their parents even after independence. (Nowak, 1991; Nowak and Paradiso, 1983)

  • Parental Investment
  • precocial
  • female parental care
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • provisioning
      • female
    • protecting
      • female
  • post-independence association with parents


Life expectancy of chinchillas and viscachas varies by genus. Mountain viscachas (genus Lagidium) typically live around 3 years in the wild, but captive individuals can reach up to 19 years of age. Plains viscachas (genus Lagostomus) live 7 to 8 years in the wild, with one captive individual reaching over 9 years of age. Chinchillas (genus Chinchilla) seem to be the longest lived members of the family Chinchillidae, with lifespans of approximately 10 years in the wild and over 20 years in captivity. (Jackson, et al., 1996; Nowak and Paradiso, 1983)


Chinchillas and viscachas are highly social. They live in colonies that range in size from 4 to 75 individuals. Chinchillas (genus Chinchilla) and mountain viscachas (genus Lagidium) both live in montane environments, making communal dens in crevices between rocks. In contrast, Argentine plains viscachas (Lagostomus maximus) - the only extant member of the genus Lagostomus - live at lower elevations in grasslands or deserts and construct large underground burrows called viscacheras. They bring objects such as sticks, dried dung, and bones to their vizcacheras. The purpose of this behavior is not well understood, but it may be involved in scent marking, flood prevention, or protection from predators. All chinchillas and viscacheras are known to clean their fur and skin by taking dust baths. (Branch, 1993; Branch, et al., 1994; Hsu, et al., 2015; Jackson, et al., 1996; Nowak, 1991; Nowak and Paradiso, 1983; Tomassini, et al., 2019)

Communication and Perception

In chinchillas and viscachas, almost all intraspecific communication involves auditory or chemical signaling, including urinating, growling, teeth chattering, and other, more specific vocalizations. There is relatively little information regarding the communication methods of species in the family Chinchillidae due to recent population declines. Chinchillas and viscachas are typically not aggressive toward conspecifics except during the mating season. (Nowak, 1991; Nowak and Paradiso, 1983)

Food Habits

All chinchillas and viscachas are herbivores. Their diets primarily consist of shrubs, forbs, and grasses, although the specific plant species in their diet vary depending on geographic location. (Nowak, 1991; Nowak and Paradiso, 1983)


Chinchillas and viscachas serve as prey for larger mammals, birds, and reptiles, although specific predators vary depending on geographic location.

Species in the family Chinchillidae have several adaptations to avoid predators, some of which are species-specific. For example, chinchillas (genus Chinchilla) can release large patches of their fur to potentially escape predators that grab them. Also, Argentine plains viscachas (Lagostomus maximus) fill their burrow systems with sticks, dried dung, and bones, which likely makes it more difficult for predators to get in. All species the family Chinchillidae live in groups, which affords them further protection from predators. If an individual detects a predator nearby, they produce alarm calls to alert other members of their social group. (Branch, et al., 1994; Hsu, et al., 2015; Jackson, et al., 1996; Tomassini, et al., 2019)

Ecosystem Roles

Members of the family Chinchillidae are herbivores that impact the densities of different plant species in their range. They also serve as sources of prey for large mammals, birds of prey, and reptiles.

In addition to their roles as herbivores and prey species, Argentine plains viscachas (Lagostomus maximus) also play a role as ecosystem engineers. They dig large burrow systems, called viscacheras, many of which support the same social group for multiple generations. During the construction of new viscacheras, Argentine plains viscachas may move upwards of 80 m^3 of soil. They also fill their viscacheras with objects, such as sticks, dung, and bones. Other animals, such as burrowing owls (Athene cunicularia) and lesser grisons (Galictis cuja) make use of both occupied and abandoned viscacheras.

Economic Importance for Humans: Positive

All members of the family Chinchillidae are traditionally hunted for meat and fur, but recent protections have been put in place to prevent poaching of wild populations. Long-tailed chinchillas (Chinchilla lanigera) are part of the pet trade and have also contributed to biomedical research; they have been used to study auditory systems because their hearing range is similar to humans and their tympanic bullae are easily accessible. (Hsu, et al., 2015; Martin, 2012; Nowak, 1991; Nowak and Paradiso, 1983)

  • Positive Impacts
  • pet trade
  • food
  • body parts are source of valuable material
  • research and education

Economic Importance for Humans: Negative

There are relatively few negative economic impacts associated with species in the family Chinchillidae, since they primarily live in montane areas that are not near human settlements. However, Argentine plains viscachas (Lagostomus maximus) live in grasslands and may eat crop plants. Furthermore, their extensive burrow systems can disrupt farming practices or lead to injuries. (Nowak, 1991; Nowak and Paradiso, 1983; Nowak, 1991; Nowak and Paradiso, 1983)

  • Negative Impacts
  • crop pest

Conservation Status

For many species in the family Chinchillidae there is a lack of information regarding conservation status. Both extant species of chinchilla (genus Chinchilla) are endangered and are currently experiencing population declines due to habitat loss. Ecuadorian mountain viscachas (Lagidium ahuacaense) are listed as data deficient, but there is only one known population and the group of scientists that described the species advised they be listed as critically endangered. Wolffsohn's viscachas (Lagidium wolffsohni) are also considered to be data deficient by the IUCN Red List, but they are considered endangered in Argentina. Northern mountain viscachas (Lagidium viscacia) are listed as a species of least concern and their populations are currently considered stable. Argentine plains viscacha (Lagostomus maximus) are also listed as a species of least concern, but there is a notable lack of information on populations in large parts of their geographic range. There are no conservation measures in place for chinchillas or viscachas specifically. However, there is one known population of Wolffsohn's viscachas on protected and it is possible that the geographic ranges of other species include protected lands, such as national parks. (Nowak, 1991; Nowak and Paradiso, 1983; Roach, 2016a; Roach, 2016b; Roach, 2016c; Roach, 2016d; Roach, 2016e; Roach and Kennerley, 2016; Roach and Kennerley, 2017; Spotorno, et al., 2004)

  • IUCN Red List [Link]
    Not Evaluated


Riley Massiha (author), Colorado State University, Galen Burrell (editor), Special Projects.



living in the southern part of the New World. In other words, Central and South America.

World Map


uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


uses smells or other chemicals to communicate


used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.


active at dawn and dusk


animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females


an animal that mainly eats leaves.


A substance that provides both nutrients and energy to a living thing.


Referring to a burrowing life-style or behavior, specialized for digging or burrowing.


An animal that eats mainly plants or parts of plants.


offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).


having the capacity to move from one place to another.


This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.


active during the night

pet trade

the business of buying and selling animals for people to keep in their homes as pets.


having more than one female as a mate at one time


specialized for leaping or bounding locomotion; jumps or hops.

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

seasonal breeding

breeding is confined to a particular season


remains in the same area


reproduction that includes combining the genetic contribution of two individuals, a male and a female


associates with others of its species; forms social groups.

soil aeration

digs and breaks up soil so air and water can get in


uses touch to communicate


Living on the ground.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.


A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.


uses sight to communicate


reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

young precocial

young are relatively well-developed when born


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