Guinea Pig

About the guinea pig

The guinea pig, also called the domestic guinea pig, cavy, or domestic cavy, is a species of rodent in the genus Cavia, family Caviidae. It does not exist in the wild; it is descended from closely related wild cavy species, most likely C. tschudii, based on molecular and skeletal studies published between 2007 and 2010, with C. aperea and C. fulgida as other close relatives. Domestic guinea pigs typically weigh 700 to 1,200 g (1.5 to 2.6 lb) and measure 20 to 25 cm (8 to 10 in) in length, though some livestock breeds reach 3 kg (6.6 lb) at full growth. Most guinea pigs are furred, though one laboratory-derived breed, the skinny pig, is largely hairless, while other breeds, including the Peruvian, the Silkie, and the Texel, carry long fur. All have four front teeth and small back teeth; the front teeth grow continuously, so the animals chew regularly to wear them down.

The species was domesticated as early as 5000 BC by tribes in the Andean region of South America, in what is now the southern parts of Colombia, Ecuador, Peru, and Bolivia, initially as a food source, following the earlier domestication of South American camelids in the same region. Regionally the animal is known as cuy, a Spanish word derived from the Quechua quwi, and the Moche people of ancient Peru depicted guinea pigs often in their art; Spanish settlers recorded the guinea pig as the Inca people's preferred sacrificial animal, used in rituals believed to appease the gods, accompany the dead, or read the future. Between about 1200 and the Spanish conquest of 1532, Andean peoples used selective breeding to develop many of the varieties that underlie modern domestic breeds, and the animal remains a food source in the region today. Spanish, Dutch, and English traders brought guinea pigs to Europe in the early 1500s, where they quickly became fashionable exotic pets among the upper classes and royalty, including Queen Elizabeth I; the earliest written account of the animal dates to 1547, from a description written in Santo Domingo.

Despite the name, guinea pigs are not native to Guinea and are not closely related to pigs at all. Why the animal is called a "guinea" pig is unclear; one theory holds that traders brought the animals to Europe by way of Guinea, leading people to assume that was their origin, while "guinea" was also used generally in English for any distant, unfamiliar country. Another theory traces "guinea" to a corruption of "Guiana," a region of South America. As for "pig," the animal has a build somewhat like a pig's, with a large head relative to its body, a stout neck, and a rounded rump with no meaningful tail, and it makes sounds resembling a pig's grunts while spending much of its time eating — traits that may have inspired the name.

Behavior and diet

Guinea pigs are social animals that, in the wild-type ancestral form, live in small groups, or herds, made up of several females (sows), a male (boar), and their young, which are called pups rather than piglets. Wild-type cavies live on grassy plains, occupying an ecological niche similar to cattle, moving in herds while eating grass and other vegetation; they do not store food, dig their own burrows, or build nests, instead sheltering in burrows made by other animals or in natural crevices and tunnels. They are crepuscular, most active at dawn and dusk, when predators have a harder time spotting them. In captivity, veterinary guidance recommends social housing, environmental enrichment such as hides and other structures, constant access to hay, and enough space to keep stress levels low; males and females are typically kept separate unless breeding is intended.

Guinea pigs are skittish animals that startle easily, responding to danger by freezing in place for long stretches or bolting for cover with quick, darting movements; a group of startled guinea pigs may "stampede" in scattered directions to confuse a predator. When excited, they sometimes perform repeated small hops in the air, a behavior known as popcorning. They are capable swimmers, though they dislike being wet, are poor climbers, and are not especially agile, though they can clear small obstacles. The animals engage in social grooming and self-grooming, secreting a milky-white substance from their eyes that gets worked into the fur during the process; groups of males often chew each other's hair as a way of establishing hierarchy, alongside other dominance behaviors including biting, especially of the ears, piloerection, aggressive noises, head thrusts, and leaping attacks.

Guinea pigs communicate mainly through vocalization. The most familiar call, the "wheek," is a loud, onomatopoeic whistle-like sound made in general excitement — often around an owner or at feeding time — or when a lost guinea pig is calling for others. Guinea pig eyesight is weaker than a human's for distance and color, though the animals see across a wider angle of view, about 340 degrees, and perceive partial color. Their hearing, sense of smell, and sense of touch are all well developed, and their activity is scattered through the day in short bursts followed by brief sleep, rather than following a strict daily rhythm, aside from an avoidance of intense light.

Range and habitat

The guinea pig does not exist as a wild species; it was domesticated from wild cavies native to the Andean region of South America, covering the present-day southern parts of Colombia, Ecuador, Peru, and Bolivia. Its closest wild relatives, including the montane guinea pig, still live in various parts of South America today. Since domestication, guinea pigs have spread worldwide as pets, laboratory animals, and, in parts of the Andes, a continuing food source, with many households in the Andean highlands still raising them.

Conservation status

The guinea pig is Not Evaluated (NE) on the IUCN Red List. Domestic animals aren't assessed on the Red List, and the guinea pig exists only as a domesticated animal, with no wild population of its own. Its closest wild relatives, the cavies of South America, are separate species.

Andean peoples domesticated it as early as 5000 BC as a food animal, and today it is kept as a pet worldwide.