By Megan Schober

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Rodentia
Suborder: Hystricomorpha
Family: Caviidae
Subfamily: Caviinae
Genus: Cavia
Species: Cavia porcellus

Geographic Range

When Europeans first arrived in South America, they found cavies occurring from northwestern Venezuela to central Chile, kept as domesticated animals by the people who lived in this region. Traders subsequently brought Cavia porcellus to Europe, where they adopted the name guinea pig from Europeans who believed them to be from Guinea. The species does not exist in the wild, but domesticated guinea pigs are now found worldwide in captivity.
Biogeographic Regions:
nearctic (introduced ); palearctic (introduced ); oriental (introduced ); ethiopian (introduced ); neotropical (native ); australian (introduced ).


Because guinea pigs are a domesticated animal, they are kept by humans in differing habitats. As pets they are normally kept in cages or aquariums with wood-shavings as bedding. In South America where the cavy is used as a food source, guinea pigs can be kept in specialized huts or they are allowed to run free and scavenge. Due to the latter situation, it is believed that some feral colonies of guinea pigs may be present in some South American countries.
Terrestrial Biomes:
savanna or grassland ; forest .

Physical Description

0.26 to 0.33 kg
(0.57 to 0.73 lbs)

Cavia porcellus are stocky animals with relatively short legs. A full-grown adult is usually between 200 and 500 mm in length. The coat of a guinea pig can be a variety of colors, lengths and textures. Some common colors are white, black, red, cream, lilac, and brown or any combination of these colors. The length and texture of the pelage depends upon the breed of the cavy. Abyssinians have a short, coarse coat that has "rosettes" (cowlicks) throughout the fur. Peruvians and Shelties have long straight hair that typically grows an inch per month. There are also smooth, short haired cavies. Guinea pigs have no external tail. They have four digits on the forefeet and three digits on the hind feet. They have very sharp claws on all digits as well.
Some key physical features:
endothermic ; bilateral symmetry .


Guinea pigs breed continuously throughout the year, but birth rate peaks in the spring. Male cavies reach sexual maturity at the age of three months and females at the age of two months. Females are polyestrous with their estrous cycles lasting on average about 16.5 days. When a pregnant female is about ready to give birth, males crowd around her and try to obtain the position of dominant male in order to protect her. The male seeks to protect the female because immediately following birth, she has a postpartum estrous that will last for only about a half of a day. The dominant male then mates with the female and continues to protect her to keep other males from mating with her. The gestation period is around 68 days, and a female will give birth to anywhere between 1 and 13 young, with four being the average litter size. A female can have a maximum number of five litters per year. Each young weighs around 100 g. Guinea pigs are well-developed at birth. They are born with hair and able to run and eat solid food all within the first day of their lives. Females have a single pair of inguinal mammae from which the young will suckle from for up to three weeks, although they can survive after only five days of nursing.

Number of offspring

1 to 8; avg. 4.30

Gestation period
58 to 75 days; avg. 68 days

Birth Mass
85 g (average)
(2.99 oz)
[External Source: AnAge]

Time to weaning
14 days (average)

Age at sexual or reproductive maturity (female)
76 days (average)
[External Source: AnAge]

Age at sexual or reproductive maturity (male)
76 days (average)
[External Source: AnAge]

Key reproductive features:
gonochoric/gonochoristic/dioecious (sexes separate); sexual .


Guinea pigs are very social animals that prefer to live in groups of five to ten. Sometimes these groups cluster to form a colony. These animals are very vocal and display several types of distinct vocalizations. They "squeak" when excited and "chirp" when under stress. Guinea pigs also make a "tooth-chatter" noise that sounds like a very loud purr. This noise can signify a threat or submission. Cavies have made great pets -- especially for children -- because they typically do not bite, even when handled improperly.
Key behaviors:
motile ; social .

Food Habits

Cavies are strictly herbivorous. Having been domesticated, they rely mostly on humans for diet. Their diet consists typically of commercial pellets, fruits and vegetables. They will eat almost any type of vegetable, but they prefer green leafy vegetables such as carrot tops and lettuce. Like humans, guinea pigs lack the ability to synthesize Vitamin C, therefore they must get plenty it in their diets or they will develop scurvy. Commercial guinea pig pellets contain the proper amount of vitamin C in order to keep the animal healthy.

Primary Diet:
herbivore (folivore ).

Economic Importance for Humans: Positive

The guinea pig has been used as a food source for hundreds of years in the countries of Ecuador, Peru and Bolivia. The guinea pig has also been an invaluable source in research laboratories where they have been used in fields such as nutrition, pathology, genetics, toxicology, in the isolation of bacteria, and the production of serum.

The cavy is also an excellent pet. There also exist guinea pig "clubs" and associations where it is possible to show animals. Some show-quality breeds are sold in excess of a thousand dollars.

Ways that people benefit from these animals:
food .

For More Information

Find Cavia porcellus information at


Megan Schober (author), University of Michigan.


Graur, D. 1991. Nature. 351 No. 6328: 649-652

Nowak, R.M. 1991. Walker's Mammals of the World, Fifth Edition. Johns Hopkins University Press, Baltimore. 910-912 pp.

Ragland, K. 1988. Guinea Pigs. T.F.H. Publications, New Jersey

Disclaimer: The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.



From Wikipedia, the free encyclopedia

The guinea pig (Cavia porcellus), also commonly called the Cavy, is a species of rodent belonging to the family Caviidae and the genus Cavia. Despite their common name, these animals are not pigs nor do they come from Guinea. They originated in the Andes, and studies based on biochemistry and hybridization suggest they are domesticated descendants of a closely related species of cavy such as Cavia aperea, C. fulgida, or C. tschudii, and therefore do not exist naturally in the wild.[1][2] The guinea pig plays an important role in the folk culture of many Indigenous South American groups, especially as a food source, but also in folk medicine and in community religious ceremonies.[3] Since the 1960s, efforts have been made to increase consumption of the animal outside South America.[4]

In Western societies, the guinea pig has enjoyed widespread popularity as a household pet since its introduction by European traders in the 16th century. Their docile nature, their responsiveness to handling and feeding, and the relative ease of caring for them, continue to make the guinea pig a popular pet. Organizations devoted to competitive breeding of guinea pigs have been formed worldwide, and many specialized breeds of guinea pig, with varying coat colors and compositions, are cultivated by breeders.

Biological experimentation on guinea pigs has been carried out since the 17th century. The animals were frequently used as a model organism in the 19th and 20th centuries, resulting in the epithet "guinea pig" for a test subject, but have since been largely replaced by other rodents such as mice and rats.

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