Do Guinea Pigs Exist in the Wild?

Plus, why do they die so easily?

A baby guinea pig

After debuting at no. 1 on the box-office charts last weekend, the animated comedy G-Force has animal groups concerned about a possible movie-inspired spike in guinea pig purchases among negligent kids. The guinea pig is commonly thought of as a domestic pet. Does it exist in the wild, too?

No, but its ancestors do. The domesticated guinea pig, or cavia porcellus, is thought to be descended from the Brazilian Guinea Pig, the Shiny Guinea Pig, or the Montane Guinea Pig, which roams free in the Andean region of South America. The wild species of guinea pig, or cavy, tend to be less colorful—mainly gray and brown—and have longer fur than their famous domesticated descendant. They live in groups of five to 10 and are quite agile. Whereas pet guinea pigs will “popcorn” in their cages, wild ones can actually jump into the air.

The domestication of guinea pigs dates back to around 5000 B.C., when the native people of Peru and Bolivia started breeding the beasts for food or religious ceremonies. (Or both: One famous Peruvian painting from 1753 shows Jesus Christ and his disciples dining on guinea pig at the Last Supper.) It’s still common for Andean households to have guinea pigs—or cuy, as they call them—scurrying around the kitchen. It wasn’t until the 16th century that Spanish traders brought guinea pigs back to Europe, where they became popular pets among the aristocracy. (Queen Elizabeth I supposedly had one.) Guinea pigs were then bred for certain traits—fur color, size, temperament—to produce the most common types found today, including the English shorthair and the Abyssinian. No one knows exactly why they’re called guinea pigs, but three theories persist: They originated in Guyana, they passed through French Guinea in West Africa on their way to Europe, or they were sold for a guinea.

Scientists started experimenting on guinea pigs as far back as the 17th century because of the animal’s remarkable docility. Worst-case scenario, a frightened guinea pig will run around in circles; other times, he’ll freeze in terror. Guinea pigs are also useful as test subjects because, like humans, they don’t produce their own vitamin C. They can therefore be used to study scurvy, or vitamin C deficiency, and other bone and cartilage ailments. Guinea pigs are also susceptible to infection, which made them useful in the development of germ theory in the late 19th century.

Bonus Explainer: Why do guinea pigs die all the time? Because they’re fragile. They need just the right diet to survive: ideally hay, vegetables, and vitamin C. (Food pellets usually combine these ingredients.) They also need to eat constantly or their complex digestive system will stop working. They’re not good with temperature changes: Anything warmer than 80 degrees can lead to dehydration. Their airways are sensitive, too, so strong aromas—particularly from bedding made of pine chips or cedar chips—can irritate their lungs and sinuses and produce upper respiratory-tract infections. Guinea pigs are also vulnerable to mange mites—bugs that burrow under their skin and induce scratching, biting, hair loss, and sometimes seizures. Their teeth are another hazard: If they get too long, they can grow together and form a bridge over the mouth, making eating impossible. Guinea pigs are also prone to stress—loud noises and other animals bother them—which can exacerbate other afflictions.

Got a question about today’s news? Ask the Explainer.

Explainer thanks Jeleen Briscoe of the University of PennsylvaniaSchool of Veterinary Medicine, Richard Bulliet of Columbia University,andHeather Jones of the Guinea Pig Resource Center.