Guinea pigs are interesting little animals widely kept as pets in many countries. These animals are part of the rodent family, but their bodies are not shaped like most other rodents. The short, stubby body of a guinea pig stands out among rodents and makes many people wonder if these animals have tails hidden under all that fur!
However, guinea pigs do not have tails at all. These rodents belong to the Caviidae family, none of which have tails. Guinea pigs do have internal tail bones, but external tails are not beneficial for these animals in the wild and are likely to make them more susceptible to predation.
The thick fur that guinea pigs have can make it difficult to see if they have tails, and it can obscure several bodily features of these animals. Let’s explore the anatomy of the guinea pig a little deeper to learn about guinea pig structure and why they are one of the only tailless rodent species.
Do Guinea Pigs Have Tails?
Most rodents have long tails to assist with balance and climbing, but guinea pigs do not appear to have one. Although guinea pigs are rodents, they are not part of the same family of rodents that possess tails, such as rats, rabbits, or mice.
Guinea pigs belong to the family Caviidae, and most species in this family do not have tails. The rodents in this family are described as having short, heavy bodies, big heads, and no tails. Guinea pigs have bodies that are ill-equipped for climbing and thus have no use for tails. A tail in their case would simply make them an easier catch for predators.
Ancient ancestors of the guinea pig are documented as having tails, as found in archeological evidence, but these animals outgrew the need for a tail. The guinea pig’s tail regressed over time until we arrived at the modern guinea pig that has no tail at all.
Why Do Guinea Pigs Not Have Tails?
Guinea pigs belong to the family of rodents that do not have tails, which is relatively rare in the rodent world. Very few species in the same family as guinea pigs have tails but share similar characteristics and attributes.
There is no definitive answer regarding why guinea pigs do not have tails. The ancestors of these animals had tails, but the modern species has no tail to speak of.
It is likely that guinea pigs outgrew the need for tails, and the environment in which they live, how they eat, how they move, and what they do to survive does not require a tail.
Some theories state that guinea pigs evolved to have no tail to make themselves more difficult for predators to catch. Without a long tail protruding from them, guinea pigs are less likely to be taken prey by predators, which is an evolutionary advantage.
However, while it is not clear why guinea pigs do not have tails, we can draw some conclusions based on why other rodents do have this feature.
Tails are primarily used for balance or defense. Some rodents, such as beavers, have tails that are highly functional and can be used as tools for constructing shelters, while other rodents, such as rats, only use their tails for balance while climbing.
Comparing these animals to guinea pigs, the reasons why they do not have tails become clearer.
Guinea pigs do not climb, they do not build shelters or dams like beavers, they are not strong enough to defend themselves with a tail, and they are known to burrow underground.
Without the need to use a tail for balancing, building, or defense and the fact that tails can be bothersome while burrowing, it is clear that guinea pigs simply do not need tails. Having a tail would only make them more susceptible to predators, and less likely to survive.
For these reasons, guinea pigs have developed bodies that do not have tails. These animals do not need a tail and have a higher chance of survival without one.
Can Guinea Pigs Have Tails?
The reason why many people wonder if guinea pigs have tails is that some guinea pig species may have fur that sticks out in the back and can sometimes appear like a small tail. This leads guinea pig owners and potential guinea pig owners to wonder if these animals can have tails.
However, no guinea pig species have tails. There are some species of guinea pigs that are very furry and have fur that can stand up straight near their hindquarters, but this is nothing more than fur, and there are no bones or joints in these ‘tails.’
There are very rare, documented cases of guinea pigs having tails, but only when born with deformities. Like most mammals, including humans, guinea pigs have a tail during certain stages of development in the womb, but this tail changes and disappears as the animal grows.
However, if the guinea pig does not develop properly, or certain aspects of the development are hindered, the tail can remain through development.
If a guinea pig is born with a tail, it is not prehensile or even moveable and is often little more than a stump, as these tails are only ever vestigial and entirely non-functional.
No guinea pig species has a tail, even though these animals do have a small tail in utero development.
Do Guinea Pigs Have Tail Bones?
Guinea pigs do not have external, visible tails unless they have a deformity, but these animals do have internal tail bones.
The section of the spine that forms the tail in utero development in guinea pigs does remain internal and is called the coccygeal vertebrae and forms what is commonly called the coccyx. This same internal structure is present in many mammals, including humans.
However, this internal bone structure does not mean that guinea pigs have tails, but it is a remnant of the ancestral species of guinea pigs that did have tails.
Guinea pigs do not have tails, but they do have internal tail bones. Unless a guinea pig is born with a defect such as a vestigial tail, these animals do not have tails, as they are part of the rodent family Caviidae, a family of rodent species that has no tail whatsoever.
Tails are evolutionarily unhelpful for guinea pigs and may even make these animals more susceptible to succumbing to predators. Guinea pigs have therefore evolved over time to be tailless for the sake of their own survival.