
Key Differences | Capybara | Nutria |
Scientific classification | Class: Mammalia Order: Rodentia Family: Caviidae Genus: Hydrochoerus Species: Hydrochoerus hydrochaeris | Class: Mammalia Order: Rodentia Family: Echimyidae Subfamily: Echimyinae Tribe: Myocastorini Genus: Myocastor Species: Myocastor coypus |
Size | Body length: 106 to 134 cm (3.48 to 4.40 ft) Tail length: 1.2 to 2.8 inches (3 to 7 centimeters) Weight: 35 to 66 kg (77 to 146 lb) | Body length: 40–60 centimeters (15.8–23.6 inches) Tail length: 30–45 centimeters (11.8–17.7 inches) Weight: 4.5–7 kilograms (10–15.4 pounds)s) |
Appearance | – heavy, barrel-shaped body – short head – reddish-brown and yellowish-brown fur – sweat glands can be found in the surface | – Rounded, finely haired tail – Distinctive white patch on the muzzle – White whiskers – Shorter fur |
Distribution | Native range: South America Introduced: Europe, Asia, Africa, and North America. | Native range: South America Introduced: all continents except Australia and Antarctica |
Behavior | – mostly active before dusk and dawn; rest in mud holes or shallow water – spend time grazing in the late afternoon | – Primarily crepuscular; peak activity at midnight – Families formed by a male, 3–4 females, and their young |
Diet | Herbivorous; occasionally ingests aquatic plants | Herbivorous; occasionally ingests crustaceans |
Predators | Jaguars, pumas, caimans, green anacondas | Alligators, eagles, snakes, turtles, dogs, birds of prey |
Reproduction | Gestation period: 130–150 days Litter capacity: 2–3 litters a year | Gestation period: 130 days Litter capacity: 1–13 litters a year |
Lifespan | – 3-6 years in the wild – 12 years in captivity | – 3 years in the wild – 6 years in captivity |
At first glance, one cannot distinguish a capybara from a nutria; that is, if seen separately.
If placed side by side, it is quite easy to tell which is which, especially if you learn the details we shared in this article!
Although they are both rodents and therefore share similar characteristics, capybaras and nutria have different taxonomic classifications.
This is the first thing to consider when comparing two animals; if they’re grouped into different families, there’s no doubt they have at least some distinct characteristics.
Without further ado, let’s discover what makes capybaras and nutria unique! By the end of the article, you’ll be an expert at distinguishing one from another!

What Are The Major Differences Between Capybaras and Nutrias?

Capybaras are often mistaken for nutria because the two have a similar appearance.
People sometimes even use these two words interchangeably!
However, some major differences can help anyone tell them apart, among which are the size and the presence of a tail!
However, we’ll start from the very beginning – their scientific classification.
Afterward, we’ll move on to differences in appearance, behavior, habitat, diet, and reproduction.

Before we start, here are some key differences between the two:
- Capybaras are much larger than nutria.
- Capybaras don’t have a tail, while nutria do.
- Nutria have a distinctive white patch of fur on the muzzle and orange incisors.
- Capybaras are more selective than nutria in terms of diet.
- Capybara produces only one litter annually, while nutria can produce three.
Scientific Classification
Key Differences | Capybara | Nutria |
Scientific classification | Class: Mammalia Order: Rodentia Family: Caviidae Genus: Hydrochoerus Species: Hydrochoerus hydrochaeris | Class: Mammalia Order: Rodentia Family: Cricetidae Subfamily: Arvicolinae Tribe: Ondatrini Genus: Ondatra Species: Ondatra zibethicus |
Although both are rodents, capybaras and nutria are classified in different groups under the Rodentia order.
Considering that specialists classify animals in different families, subfamilies, tribes, and genera based on distinctive traits, their scientific classification is of the essence in understanding the differences between them.

Capybaras are scientifically called Hydrochoerus hydrochaeris.
They are part of the Caviidae family, which includes subfamilies of rodents native to South America.
This makes capybaras close relatives of the famous guinea pigs.
Further down their classification, capybaras are grouped under the Hydrochoerinae subfamily, which consists only of capybaras and rock cavies.
The Hydrochoerus genus has five species, of which only two are extant – the greater capybara (capybara) and the lesser capybara.

Nutrias are scientifically called Myocastor coypus.
They are part of the Echimyidae family, which is classified under Rodentia.
This family consists of neotropical spiny rats classified within several subfamilies, including Echimyinae, where nutrias are grouped.
Then, nutrias are part of the Myocastorini tribe, which consists of rodents with long upper incisor roots and medium-sized lower incisor roots.
This makes nutria closely related to armored rats and painted tree rats.
Size
Key Differences | Capybara | Nutria |
Size | Body length: 106 to 134 cm (3.48 to 4.40 ft) Tail length: 1.2 to 2.8 inches (3 to 7 centimeters) Weight: 35 to 66 kg (77 to 146 lb) | Body length: 40–60 centimeters (15.8–23.6 inches) Tail length: 30–45 centimeters (11.8–17.7 inches) Weight: 4.5–7 kilograms (10–15.4 pounds) |

Capybaras are much larger than nutria.
Adults grow to 106-134 centimeters (41.7-52.8 inches) in length and 50–62 centimeters (20–24 inches) in height (at the withers).
Their weight varies between 35 and 66 kilograms (77–146 pounds), although the maximum recorded weight was 73.5 kilograms (162 pounds) – as much as a human being!
Female and male capybaras are sexually dimorphic, as the former are heavier than the latter.

In contrast, a nutria is half the size of a capybara.
It reaches only 40–60 centimeters in body length.
However, we must mention a major difference between the two – while capybaras have vestigial tails, or, better said, they do not have them at all, nutria have quite long tails, which add 30–45 centimeters (12–18 inches) to the body length!
Additionally, nutrias aren’t as heavy as capybaras, as they weigh only 4.5–7 kilograms (10–15 pounds) on average, although some individuals may reach an extraordinary weight of 17 kilograms (37 pounds), which is still less than the weight of an average capybara.
Appearance
Key Differences | Capybara | Nutria |
Appearance | heavy, barrel-shaped body short head reddish-brown and yellowish-brown fur sweat glands can be found in the surface | Rounded, finely haired tail Distinctive white patch on the muzzle White whiskers Shorter fur |

As mentioned, capybaras can be distinguished from nutria by the fact that they lack a tail.
Besides this, the capybara has a barrel-shaped body and a broad head.
Its ears are short and rounded, while the snout is large but blunt.
The fur is typically reddish-brown on top, turning into light brown on the underside.

A nutria, on the other hand, has dark brown fur with distinctive white hairs on the muzzle.
Its ears are slightly smaller and more rounded than those of a capybara.
Moreover, the muzzle isn’t as broad and blunt.
Another distinguishing nutria characteristic is the prominent orange color of its large incisors.
Overall, a nutria is more similar to a beaver than to a capybara.
Habitat and Distribution
Key Differences | Capybara | Nutria |
Distribution | Native range: South America Introduced: Europe, Asia, Africa, and North America. | Native range: South America Introduced: all continents except Australia and Antarctica |
While both capybaras and nutria are native to South America, the latter have been introduced to Europe, Asia, Africa, and North America.
Capybaras live in all South American countries except Chile.
They’re fond of forested areas that are close to water sources like rivers, lakes, or marshes.

They are social and highly adaptable creatures, often spotted in South American parks and zoos.
Many colonies are found on extensive cattle ranches, as they’re well-managed and make for excellent habitats.
Although not as susceptible to trade as nutria and legally protected in some parts of the world, capybaras are kept in zoos or as pets outside South America.
Nutrias are found in the temperate and subtropical regions of South America and on all the other continents except Australia and Antarctica.

Like capybaras, nutria are semi-aquatic and live close to water sources.
They’re most common in freshwater wetlands but may also be spotted in salt and brackish marshes.
Another difference between capybaras and nutria is that while both are known to live in burrows, capybaras often spend time in the dense vegetation around a water source.
By contrast, nutria occupy burrows created by other rodents, build floating rafts, or stay in partially underwater dens.
On the other hand, nutria can adapt well to urban areas and will undoubtedly accept food from humans.
Behavior
Key Differences | Capybara | Nutria |
Behavior | mostly active before dusk and dawn; rest in mud holes or shallow water spend time grazing in the late afternoon | Primarily crepuscular; peak activity at midnight Families formed by a male, 3–4 females, and their young |

Capybaras are mostly active before dusk and dawn.
When the temperatures are at their highest, they rest in mud holes or shallow water.
Then, they spend time grazing in the late afternoon, sometimes until midnight.
Afterward, capybaras rest for a while and then graze again before dawn.
Grazing takes several hours a day.
When looking for food, capybaras often walk in line along established trails.
Nutria have a similar activity pattern, as they’re primarily active around dusk and sunset.

However, the peak of their activity is around midnight, when capybaras are typically resting.
Nutria may also forage during the day if food is scarce.
Both capybaras and nutria are social creatures that live in colonies.
Capybaras are known to live in groups of 10-20 individuals, although some can consist of up to 100 capybaras, especially during the dry season.
Nutria colonies are typically smaller but can occasionally include up to 20 rodents.
Additionally, both species are excellent swimmers and can stay submerged for up to five minutes.
Diet
Key Differences | Capybara | Nutria |
Diet | Herbivorous; occasionally ingests aquatic plants | Herbivorous; occasionally ingests crustaceans |
Capybaras and nutria are herbivores that feed on aquatic plants.

Capybaras, however, may also eat fruits if the opportunity presents itself.
On the other hand, they are highly selective and prefer specific plants over others, especially during the wet season.
Capybaras rely on back-and-forth movements to chew.
Another noteworthy characteristic of capybaras is that they eat their own poop!
That sounds gross, and we agree, but the truth is that the poop is actually beneficial, as it contains bacterial gut flora that facilitates grass cellulose digestion and vitamin absorption.
They may sometimes regurgitate their food to chew it again, just like cows!

Nutria aren’t as selective as capybaras.
If they stumble upon a plant they like, they’ll eat it whole, even the roots and the rhizomes.
Sometimes they may also ingest insects or freshwater crustaceans along with plants.
To be well-fed and content, nutria must ingest 25% of their total body weight daily.
In the United States, nutria feed primarily on cordgrasses, spikerushes, pickerelweeds, cattails, and flatsedges.
Predators
Key Differences | Capybara | Nutria |
Predators | Jaguars, pumas, caimans, green anacondas | Alligators, eagles, snakes, turtles, dogs, birds of prey |

In the wild, capybaras often fall prey to jaguars, pumas, and other similar big cats, as well as to birds of prey like eagles.
Caimans and green anacondas have often been spotted hunting and killing capybaras.
Besides this, humans pose a threat to the capybara population.
Considering how small they are, nutria have more predators in the wild, among which are alligators, eagles, turtles, snakes, garfish, dogs, and birds of prey like hawks and eagles.
In some parts of the world, licensed hunters hunt nutria as non-game animals.
Reproduction and life cycle
Key Differences | Capybara | Nutria |
Reproduction | Gestation period: 130–150 days Litter capacity: 2–3 litters a year | Gestation period: 130 days Litter capacity: 1–13 |

Capybaras and nutrias mate all year, and the peak of the mating season typically depends on their geographic location.
Here are some key differences between capybaras and nutria in terms of reproduction and life cycle:
- Capybaras become sexually active at 1.5 years old or when they weigh at least 30–40 kilograms (pounds). Nutria become sexually active at 3–4 months old.
- Capybaras have a gestation period of 130–150 days and produce between 1–8 young per litter. Nutria have a gestation period of 130 days and give birth to 1–13 young per litter.
- Most female capybaras produce only one litter per year, exceptionally two litters. Female nutria typically produce 2–3 litters a year.

- Baby capybaras and nutria are precocial. Baby capybaras join their group once they can move. They start eating grass as early as one week after birth. Baby nutria can eat vegetation within hours after birth.
- Capybaras have a lifespan of 8–10 years but typically die within the first 4 in the wild due to predation. In captivity, they may live up to 12 years. Nutria have a lifespan of 3–6 years in the wild and up to 12 years in captivity.
Human Interaction
Capybaras and nutrias have been assessed as Least Concern by the IUCN Red List, which indicates they’re dealing quite well with what threatens their population, including humans.

However, the degree to which they interact with humans is different.
Let’s discuss capybaras first.
Their population numbers are quite stable within their range, although they’re hunted for meat and skin in some areas.
If kept in captivity, capybaras do quite well, sometimes doubling their life expectancy.
They’re docile and social creatures, and people can hand-feed them.
It is illegal in some parts of the world to keep capybaras as pets, although some states in the U.S., like Florida and Arizona, allow it.

In Japan, capybaras are kept in zoos and have become quite a popular species!
Like other animals, capybaras carry various zoonotic agents like salmonella, toxoplasmosis, and rabies.
Despite this, capybaras are regarded as cool rodents, which cannot be said about nutria!
Let’s find out why!
If we turn to nutria, however, there’s much more to say, as their interaction with humans is much more extensive and dates back to the 19th century.

The first attempt at farming nutria occurred in the 1880s in Europe, although efficient farming developed only in the 1920s in South America.
Nutria were farmed for fur and meat.
Additionally, some farmers released them into the wild to clear water sources of aquatic vegetation.
Today, hunting nutria without a license is considered illegal in many parts of the world.
Some nutria populations escaped from captivity and quickly spread through various regions, which is why they now have such a wide distribution.

As a consequence of their rapid spread, nutria have become pests that affect aquatic vegetation, crops, irrigation systems, and various man-made structures.
This shouldn’t be surprising, considering how infamous they are for eating whole plants and leaving no scraps behind!
This behavior promotes wetland, farmland, and marsh destruction and, therefore, equals direct environmental damage.
Furthermore, these rodents serve as hosts of multiple parasites and diseases, including roundworm nematode parasites, tapeworms, blood flukes, liver flukes, fleas, ticks, salmonellosis, chlamydia psittaci, toxoplasmosis, and rabies.

Consequently, compared to capybaras, nutria are now the subject of many population control efforts.
As global temperatures increase, the range of nutria is expected to extend to the north as well, possibly causing further damage.
Conclusion
In conclusion, distinguishing between capybaras and nutrias may initially seem challenging, but armed with the knowledge we’ve provided in this article, you’ll become an expert at telling these two rodents apart.
Despite their superficial similarities, they belong to different taxonomic classifications, which is a crucial starting point in understanding their differences.
From their scientific names to size, tails, fur patterns, and dietary habits, capybaras and nutrias exhibit distinct characteristics that set them apart.
Capybaras, the larger of the two, lack tails and have a broader head, while nutrias sport long tails, distinctive white hairs on their muzzle, and bright orange incisors.
Their habitat and distribution also vary, with capybaras primarily found in South America and nutrias having a global presence due to introductions in other continents.
Behaviorally, both species are social creatures, but their activity patterns and foraging habits differ.
Capybaras graze selectively and rest in mud holes, while nutrias are more omnivorous, eating a wider range of plants and occasionally insects or crustaceans.
When it comes to reproduction, capybaras and nutrias have different timelines and litter sizes, with capybaras producing only one litter per year and nutrias having more frequent reproductive cycles.
Human interaction with these rodents varies as well.
Capybaras are often kept as pets or in zoos, and while they carry zoonotic agents, they generally have a positive reputation.
In contrast, nutrias have a more complex relationship with humans.
Originally farmed for fur and meat, they became pests in various regions after escaping captivity.
Their extensive range and plant-consuming habits have led to significant environmental damage, making them the focus of population control efforts.
In summary, understanding the nuances that differentiate capybaras from nutrias is not only intriguing but also essential for appreciating the diversity of wildlife in our world and managing the impact of these fascinating rodents on their ecosystems.
Sources:
- https://en.wikipedia.org/wiki/Capybara
- https://en.wikipedia.org/wiki/Nutria
- https://academic.oup.com/mspecies/article/doi/10.2307/3503784/2600593?login=false
- https://icwdm.org/species/rodents/nutria/nutria-biology/
- https://wdfw.wa.gov/species-habitats/invasive/myocastor-coypus#living
- https://www.zoo-palmyre.fr/en/birth-capybara#:~:text=Capybaras%20live%20in%20small%20groups,hunting%20pressure%20and%20the%20season.
- https://nutria.com/biology/
- https://www.britannica.com/animal/capybara-genus
- https://nhpbs.org/wild/caviidae.asp#:~:text=They%20are%20all%20found%20in,are%20active%20during%20the%20day.
- https://www.aphis.usda.gov/publications/wildlife_damage/fsc-nutria-invasive-rodent.pdf