Cavia apereaBrazilian guinea pig

Geographic Range

Brazilian guinea pigs occur in the neotropical region, but do not occur in tropical rain forests. They are native to Argentina, Bolivia, Brazil, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay and Venezuela (Dittmar, 2002; Dunnum et al., 2008). (Dittmar, 2002; Dunnum, et al., 2008)


Brazilian guinea pigs are primarily found in scrub grasslands and savannas, but also occur in the highlands of the Andes mountain range. They prefer areas of thick ground cover but can be found in disturbed habitats as well. They do not occur in tropical rain forests (Dunnum et al., 2008). Wild guinea pigs live in small groups consisting of 1 male, 1 to 2 females, and their young. They do not burrow, but instead rely on a series of tunnels and pathways constructed in dense ground vegetation (Asher et al., 2004). (Asher, et al., 2004; Dunnum, et al., 2008)

  • Range elevation
    400 to 3,000 m
    1312.34 to ft

Physical Description

Brazilian guinea pigs are medium-sized, herbivorous rodents. They are one of fifteen species of wild guinea pig in the subfamily Caviinae (Asher et al., 2004). They range in mass from 520 to 795 g, with an average mass of 637 g. They have stout bodies and a significantly reduced tail. Brazilian guinea pigs have four toes on their forefeet, while their hind feet have only three toes. Although males tend to be larger than females, brazilian guinea pigs have an average total body length of 274 mm, but range in size from 196 to 320 mm. Like most rodents, they lack canine teeth and have a dental formula of 1/1, 0/0, 1/1, 3/3. They have ever-growing teeth that are maintained at a constant length by continuous gnawing. Typically, they have brown pelage, but red and black variations also occur. Their coat is darkest along the spinal ridge and becomes increasingly light as it approaches the ventral surface of the animal. (Asher, et al., 2004; Eisenberg, 1989; Asher, et al., 2004; Eisenberg, 1989)

  • Sexual Dimorphism
  • male larger
  • Range mass
    520 to 795 g
    18.33 to 28.02 oz
  • Average mass
    637 g
    22.45 oz
  • Range length
    196 to 320 mm
    7.72 to 12.60 in
  • Average length
    274 mm
    10.79 in


Brazilian guinea pigs are polygynous, with a single male mating with multiple females (usually no more than 2; Dunnam et al., 2008). On average, males are 11% larger than females and are very aggressive towards other males. While males defend their mates from potential rivals, they do not defend territorial boundaries, as resources are widely abundant. Although mating season peaks in early spring, females may have up to 4 litters throughout the year (Asher et al., 2004). (Asher, et al., 2004; Dunnum, et al., 2008)

Compared to most rodents, brazilian guinea pigs reproduce relatively slowly. They have an extended period of gestation (62 days) and on average, have 2 well-developed pups per litter (Dunnum et al., 2008; Kraus et al., 2005). Pups are born "open-eyed" and "fully furred", and are able to move on their own hours after birth. They can eat solid food at 3 days old and are weaned by 25 days old. Brazilian guinea pigs can reproduce as early as 28 days old (Kraus et al., 2005). (Dunnum, et al., 2008; Kraus, et al., 2005)

  • Breeding interval
    Wild guinea pigs breed up to 4 times per year
  • Breeding season
    September through April
  • Range number of offspring
    1 to 5
  • Average number of offspring
  • Range gestation period
    53 to 77 days
  • Average gestation period
    62 days
  • Range weaning age
    21 to 29 days
  • Average time to independence
    32 days
  • Range age at sexual or reproductive maturity (female)
    19 to 48 days
  • Average age at sexual or reproductive maturity (female)
    29.5 days
  • Range age at sexual or reproductive maturity (male)
    18 to 46 days
  • Average age at sexual or reproductive maturity (male)
    28 days

Brazilian guinea pig females dedicate anywhere from 25 to 35 days to each litter; however, juveniles are capable of taking care of themselves as early as 5 days after birth (Eisenberg, 1989). Although nursing lasts for up to 25 days, pups can eat solid food as early as 3 days after birth. Juveniles disperse shortly after reaching sexual maturity at around 35 days old. Males invest little in the survival of their offspring, but protect females and pups for a short period after birth (Eisenberg, 1989; Asher et al., 2004). (Asher, et al., 2004; Eisenberg, 1989; Asher, et al., 2004; Eisenberg, 1989)

  • Parental Investment
  • precocial
  • female parental care
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • male
      • female
  • pre-independence
    • protecting
      • male
      • female


Although Brazilian guinea pigs can survive for up to 8 years in the wild, due high predation rates on juveniles, their average lifespan is only 3 years (Eisenberg, 1989). Captive guinea pigs can live for up to 10 years. (Asher, et al., 2004; Eisenberg, 1989)

  • Typical lifespan
    Status: wild
    8 (high) years
  • Average lifespan
    Status: wild
    3 years
  • Typical lifespan
    Status: captivity
    10 (high) years


Brazilian guinea pigs are social animals that live in small familial groups consisting of 1 male, 1 to 2 females, and their offspring (Asher et al., 2004; Rood, 1972). Familial groups often occur in clusters, with dozens of groups located in adjacent territories. They communicate through auditory signals and scent marks. Males scent mark using a gland above their anus. Although they are unlikely to scent mark specific territories, they often mark their mates and defend them against rival males (Asher et al., 2004; Beruter, Beauchamp, and Muetterties, 1974). (Asher, et al., 2004; Beruter, et al., 1974; Cassini, 1991; Rood, 1972)

Brazilian guinea pigs are both diurnal and crepuscular, venturing out into the grasslands for short periods of time to graze, then seeking cover in dense shrubs. They often graze in small groups to increase predator detection and maximize their per-capita grazing time (Cassini, 1991). (Asher, et al., 2004; Beruter, et al., 1974; Cassini, 1991; Rood, 1972)

  • Range territory size
    500 to 1000 m^2
  • Average territory size
    800 m^2

Home Range

Home ranges of Brazilian guinea pigs are between 500 and 1000 m^2, depending on resource availability. Males' home ranges are up to twice as large as those of females and usually overlap with their mates' home ranges. Optimal habitats are located near lakes or rivers and include areas with dense shrub for cover, and grass for foraging (Asher et al., 2004; Rood, 1972). (Asher, et al., 2004; Eisenberg, 1989; Rood, 1972)

Communication and Perception

Brazilian guinea pigs have two distinct scent glands, the dorsally located sebaceous gland and the perineal gland, located near the anus. Though males generally scent mark more frequently than females, both sexes scent mark with their perineal gland when their local environment has been disturbed. Scent marking is used to demarcate an individual's territory, to ward off rival males, and to attract potential mates (Beruter et al., 1974). Brazilian guinea pigs also communicate through a series of high pitched squeals and screams, which are used as warnings to other conspecifics when potential threats are detected (Eisenberg, 1989). (Beruter, et al., 1974; Eisenberg, 1989)

Food Habits

Brazilian guinea pigs are generalist grazers and are strictly herbivorous. They primarily feed on true grasses (Poaceae, formally known as Gramineae), but will forage on many other kinds of grasses as well (Asher et al., 2004). They indiscriminately feed on seeds, leaves, stems, and in some cases, roots or tubers (Kraus et al., 2005). (Asher, et al., 2004; Kraus, et al., 2005)

  • Plant Foods
  • leaves
  • roots and tubers
  • seeds, grains, and nuts


Brazilian guinea pigs are medium-sized rodents that are important prey for cats, dogs, opossums, grison, raptors, snakes, and lizards. However, because of their size, smaller predators only prey upon juveniles (Scheibler, 2004). They typically forage in dense vegetation, near protective cover. They often forage in groups, which limits the per-capita amount of time spent scanning for predators, thus increasing the per-capita time spent foraging. When potential predators are detected, they alert their group mates by way of a high pitched scream (Cassini, 1991; Rood, 1972). (Asher, et al., 2004; Cassini, 1991; Rood, 1972; Scheibler, 2004)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Brazilian guinea pigs are a major food source to many medium- to large-sized carnivores. Along with other herbivorous rodents, they help maintain grasslands by filling niches that are similar to those of grazing ungulates in Africa (Eisenberg, 1989). Also, they create a network of tunnels throughout the dense ground vegetation that are used by various species of small animals (Asher et al., 2004). Finally, Brazilian guinea pigs are hosts for various forms of parasites, including fleas (Tiamastus cavicola, Leptopsylla segnis, and Tiamastus cavicola), lice (Gliricola porcelli, Hoplopleura alata, and Polyplax spinulosa), mites (Myobia musculi and Eutrombicula bryanti), nematodes (Capillaria hepatica, Graphidioides mazzai, Trichuris gracilis, and Paraspirudera uncinata), and one species of trematode (Fasciola hepatica). (Dunnum, et al., 2008; Eisenberg, 1989)

  • Ecosystem Impact
  • disperses seeds
  • creates habitat
Commensal/Parasitic Species

Economic Importance for Humans: Positive

Brazilian guinea pigs are believed to be the parent species of domesticated guinea pigs (Cavia porcellus). Guinea pigs were domesticated as pets around 3000 years ago and are a common source of protein in some Andean cultures (Dittmar, 2002). Additionally, domesticated guinea pigs are commonly used as test subjects in biomedical research (Asher et al., 2004). (Asher, et al., 2004; Dittmar, 2002)

Economic Importance for Humans: Negative

Brazilian guinea pigs are sometimes kept as exotic pets or used as a source of protein. As a result, they may potentially be vectors of zoonotic diseases to humans. Diseases commonly associated with Brazilian guinea pigs are cryptosporidiosis, inclusion body conjunctivitis, and salmonellosis (Comparative Medicine Program - MU College of Veterinary Medicine, 2002). Guinea pigs can be hosts to various forms of parasites (fleas, lice, mites, nematodes, and trematodes), and their dander, fur, urine, and saliva are common human allergens (Zacharisen et al., 2005, Dunnum et al., 2008). ("Guinea Pig Diseases", 2002; Dunnum, et al., 2008; Zacharisen, et al., 2005)

Conservation Status

Brazilian guinea pig populations are generally stable, showing only slight declines due to human activity (Dittmar, 2002). The IUCN has classified them as a species of "least concern". They are broadly distributed, are tolerant to environmental disturbances, and have large populations throughout northern and central South America. (Dittmar, 2002; Dunnum, et al., 2008)


Elizabeth Westberg (author), University of Wisconsin-Stevens Point, Stefanie Stainton (editor), University of Wisconsin-Stevens Point, Christopher Yahnke (editor), University of Wisconsin-Stevens Point, John Berini (editor), Animal Diversity Web Staff.



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.

causes disease in humans

an animal which directly causes disease in humans. For example, diseases caused by infection of filarial nematodes (elephantiasis and river blindness).

causes or carries domestic animal disease

either directly causes, or indirectly transmits, a disease to a domestic animal


uses smells or other chemicals to communicate


active at dawn and dusk


having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

  1. active during the day, 2. lasting for one day.

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.


an animal that mainly eats seeds


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.

native range

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


having more than one female as a mate at one time

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.


uses touch to communicate


Living on the ground.


defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement


the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

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


Comparative Medicine Program - MU College of Veterinary Medicine. 2002. "Guinea Pig Diseases" (On-line). Accessed August 04, 2010 at

Asher, M., E. Spinelli de Oliviera, N. Sachser. 2004. Social System and Spatial Organization of Wild Guinea Pigs (Cavia aperea) in a Natural Population. Journal of Mammalogy, Vol. 85, No. 4: 788-796.

Beruter, J., G. Beauchamp, E. Muetterties. 1974. Mammalian Chemical Communication: Perineal Gland Secretion of the Guinea Pig. Physiological Zoology, Vol. 47, No. 2: 130-136.

Cassini, M. 1991. Foraging under Predation Risk in the Wild Guinea Pig Cavia aperea. Oikos, Vol. 62, No. 1: 20-24.

Dittmar, K. 2002. Arthropod and Helminth Parasites of the Wild Guinea Pig, Cavia aperea, from the Andes and the Cordillera in Peru, South America. The Journal of Parasitology, Vol. 88, No. 2: 409-411.

Dunnum, J., H. Zeballos, J. Vargas, N. Bernal, D. Brito, D. Queirolo, U. PARDINAS, G. D'ELIA. 2008. "Cavia Aperea. IN: ICUN Red List of Threatened Species" (On-line). The ICUN Red List of Threatened Species. Accessed August 04, 2010 at

Eisenberg, J. 1989. Mammals of the Neotropics. Chicago, IL: The University of Chicago Press.

Kraus, C., F. Trillmich, J. Kunkele. 2005. Reproduction and Growth in a Precocial Small Mammal, Cavia magna. Journal of Mammalogy, Vol. 86, No. 4: 763-772.

Oliveira, T. 1998. Herpailurus yagouaroundi. Mammalian Species, No. 578: 1-6.

Rood, J. 1972. Ecological and behavioral comparisons of three genera of Argentina cavies. Animal Behavior Monographs, No. 5: 1-83.

Scheibler, D. 2004. Geographic Variation in the Size of Mammalian Prey taken by White-Tailed Kites in the Americas. Journal of Field Ornithology, Vol. 75, No. 3: 218-222.

Touma, C., R. Palme, N. Sachser. 2001. Different types of oestrous cycle in two closely related South American rodents (Cavia aperea and Galea musteloides) with different social and mating systems.. Reproduction, No. 121: 791-801.

Trillmich, F. 2000. Effects of Low Temperature and Photoperiod of Reproduction in the Female Wild Guinea Pig (Cavia aperea). Journal of Mammalogy, Vol. 81, No. 2: 586-594.

Yensen, E., T. Tarifa. 2003. Galictis cuja. Mammalian Species, No. 728: 1-8.

Zacharisen, M., M. Levy, J. Shaw, V. Kurup. 2005. Severe allergic reactions to guinea pig. Clinical and Molecular Allergy : CMA, 3/14: 1-4. Accessed February 05, 2011 at