1. Taxonomy and Classification

The capybara belongs to the Caviidae family, which is part of the order Rodentia. Within this family, it is classified as a member of the Hydrochoerinae subfamily, and its closest relatives include the guinea pig and rock cavy. The species name Hydrochoerus hydrochaeris is derived from Greek, where "hydro" refers to water, and "choerus" means pig, indicating the species’ aquatic lifestyle and resemblance to pigs. Despite their size, capybaras share common traits with other rodents, such as ever-growing incisors, a robust digestive system, and a high level of social organization ^[1].

The capybara is the only extant species in the Hydrochoerus genus, which was previously home to other large rodents such as Hydrochoerus huanca and Hydrochoerus isthmius, which have since become extinct ^[2].

2. Morphological Features

Capybaras are notable for their impressive size among rodents. Adult capybaras typically weigh between 35 to 66 kg (77 to 146 lbs) and can measure up to 1.3 meters (4.3 feet) in length, with a height of 0.6 meters (2 feet) at the shoulder. Their bodies are barrel-shaped and adapted to a semi-aquatic lifestyle, with large webbed feet that facilitate swimming ^[3].

The fur of the capybara is coarse and brownish with a lighter underside, and they also possess small, rounded ears, which help reduce drag while swimming. The teeth of the capybara are distinctive, with four large, chisel-like incisors that continually grow throughout their lives. They are herbivorous, relying primarily on grasses, aquatic plants, and the occasional fruit or bark ^[4].

Unlike many other large mammals, capybaras have relatively short limbs that assist in both swimming and walking, although their bulk makes them slower on land compared to other species in their habitat ^[5].

Source: Encyclopedia Scientific Infographics (https://encyclopedia.pub/image/3022) 

3. Habitat and Distribution

Capybaras are primarily distributed in the tropical and subtropical regions of South America, where they are found in countries such as Brazil, Venezuela, Colombia, Ecuador, and Argentina ^[6]. They are highly dependent on wetland ecosystems, including rivers, lakes, swamps, and marshes. These aquatic environments offer the capybara both food and refuge from predators, and the species is seldom found in areas far from water ^[3].

In these habitats, capybaras prefer to live in herbaceous wetlands, areas abundant with grasses and aquatic plants, which are their primary food sources. Their adaptation to water is so ingrained that they are excellent swimmers, capable of remaining submerged for up to five minutes and using their webbed feet for swift movement through water ^[4].

4. Diet and Feeding Habits

Capybaras are herbivores, and their diet consists mainly of grasses, aquatic plants, fruits, and the occasional tree bark. Their digestive system is adapted to process large quantities of low-nutrient plant matter, with a relatively long and complex gut that allows for fermentation of cellulose ^[5].

Capybaras engage in coprophagy, the act of eating their own feces, as a means to extract further nutrients from their food. By ingesting their feces, capybaras re-digest the food in order to extract more energy, a common practice among animals with a herbivorous diet that includes tough plant matter ^[7].

The species plays a significant ecological role in controlling vegetation in wetlands and contributing to nutrient cycling. Their feeding habits also help maintain open spaces in the wetlands, facilitating other species to thrive ^[8].

5. Social Behavior and Reproduction

Capybaras are highly social animals and are known for their complex group structures. They typically live in herds that can range from 10 to 50 individuals, and sometimes even larger in ideal environments ^[3]. These groups are led by a dominant male, and they consist of females, young, and subordinate males. Social bonds are essential for capybaras, and they engage in frequent grooming, vocalization, and group activities such as resting and playing together ^[6].

Capybaras are crepuscular and diurnal, meaning they are most active during the early morning and evening hours. During the day, they often rest in groups near water, engaging in social behaviors and bathing. They communicate with a range of vocalizations, including whistles, barks, and clicks, which help maintain social cohesion within the group ^[7].

In terms of reproduction, female capybaras typically give birth to 1 to 8 pups after a gestation period of about 150 days. The young are born fully furred, with their eyes open, and are able to swim and eat grass shortly after birth ^[4]. They remain with their mothers for several months and are integrated into the social structure of the group, learning critical survival skills from older individuals ^[8].

6. Ecological Role

Capybaras are integral to their ecosystem, acting as both herbivores and prey for various predators. As herbivores, they help regulate the growth of aquatic plants and grasses, preventing overgrowth in their habitat. This creates a dynamic and balanced environment, where capybaras’ feeding behaviors allow other species, such as birds and smaller mammals, to also thrive by creating clearings and space for nesting ^[9].

In addition, capybaras themselves are an important food source for a variety of predators. These include jaguars, pumas, alligators, and crocodiles, all of which prey on capybaras in different stages of life. Although they are large animals, their vulnerability to predators underscores the necessity of social bonds and collective defense strategies ^[10].

7. Conservation Status

The IUCN Red List currently lists the capybara as being of Least Concern (LC), primarily due to its wide distribution and large population across South America. However, local populations in certain areas may be threatened by habitat destruction, hunting, and the impact of agriculture, which reduces the availability of suitable wetland habitats ^[1].

Although the capybara has no immediate large-scale conservation threats, ongoing wetland degradation caused by deforestation, urban expansion, and pollution poses a long-term risk to their habitats. Furthermore, in some regions, capybaras are hunted for their meat and skin, contributing to population declines in specific areas ^[5].

Efforts to conserve capybara populations focus on protecting wetland habitats and ensuring that agricultural and urban expansion does not overly impact these ecosystems. Furthermore, as capybaras are often protected under national wildlife protection laws, especially in countries like Brazil and Venezuela, local conservation strategies play a key role in sustaining their populations ^[6].

8. Capybaras and Human Interaction

Capybaras are increasingly known for their tame and docile behavior around humans. This has led to them becoming popular in zoos, sanctuaries, and even as pets in some regions ^[2]. However, it is important to note that while capybaras are social animals, their care requires adequate space, water access, and a diet that mimics their natural herbivorous habits ^[4].

In certain areas of South America, the capybara holds cultural significance and is often featured in local folklore and traditions. Their role in local agriculture as a source of food also leads to them being seen as an economic resource in certain rural communities ^[7].

9. Conclusion

The capybara, as the largest rodent in the world, is not just an ecological marvel but a symbol of South American biodiversity. Its social nature, combined with its adaptability to various ecosystems, makes it a key species in the wetland regions of the continent. The species’ calm demeanor and strong social bonds have earned it admiration across the world, further highlighting the importance of this species in both ecological and cultural contexts.