The capybara, recognized globally as the world’s largest living rodent, naturally draws curiosity about its presence in various tropical and subtropical regions. This semi-aquatic mammal can grow up to 4.3 feet long and weigh nearly 175 pounds. Its distinct barrel-shaped body and partially webbed feet adapt it perfectly for life near the water’s edge, leading to frequent inquiries about whether it roams the diverse landscapes of places like Puerto Rico.
Capybara Native Habitat and Range
The natural distribution of the capybara is confined almost entirely to the South American continent, ranging from Venezuela and Colombia down to northern Argentina and Uruguay. These rodents thrive in environments that offer dense vegetation and easy access to large, permanent water sources, such as flooded grasslands, tropical rainforests, and river banks.
The capybara’s physiology is built for this habitat, allowing it to swim and dive readily to evade predators like jaguars and anacondas. Their eyes, ears, and nostrils are positioned high on their heads, enabling them to remain almost completely underwater while still breathing and observing their surroundings. This dependency on year-round water defines their presence exclusively within the neotropical regions of the South American mainland.
The Status of Capybaras in Puerto Rico
Capybaras are not native to Puerto Rico, and there is no scientific evidence of an established, self-sustaining feral population on the island. The animal’s natural range is separated from the island by a significant stretch of ocean, making natural dispersal impossible. Any sightings are likely linked to escapes from the exotic pet trade, an activity that has a documented presence in Puerto Rico.
The Department of Natural and Environmental Resources (DRNA) routinely manages issues related to imported non-native animals, including the confiscation of various reptiles and mammals. Because the capybara is a desirable exotic pet, individuals could be imported and later escape or be released. However, such escaped animals are isolated incidents and have not resulted in a breeding population capable of surviving long-term in the wild.
Confusion sometimes arises due to the presence of other large, non-native rodents, such as the nutria, which is sometimes mistaken for a smaller capybara. Nutrias are also semi-aquatic and native to South America, but they are significantly smaller and possess a long, rat-like tail, a feature absent in the capybara. While the nutria is considered an invasive species elsewhere, there is no indication that it has established a presence in Puerto Rico either.
Risks of Non-Native Species Introduction
Island ecosystems are inherently fragile and particularly susceptible to the negative effects of non-native species introduction. Island flora and fauna evolved in isolation, often lacking defenses against mainland predators or competitive pressures. Non-native species are responsible for approximately 90% of all recorded species extinctions on islands globally.
The introduction of a large, rapidly reproducing rodent like the capybara could pose multiple risks to the local environment. It could introduce novel parasites or diseases to which native species have no immunity, causing widespread population declines. Furthermore, a large herbivore would compete with native fauna for limited resources, altering the balance of the island’s unique habitats. Regulatory efforts focus heavily on preventing the establishment of non-native animals because the ecological and economic damages caused by invasive species are a major threat to biodiversity.