Paca (Cuniculus paca)

MammalRodentRainforest

Overview

The paca (Cuniculus paca), or lowland paca, is a large, stout rodent of the forests of Central and South America — among the biggest rodents in its range, after the capybara and a few others. It has a chunky body, short legs, almost no visible tail, and a handsome dark-brown coat marked with several rows of pale spots and dashes along each side. A relative of the agouti, it is mostly solitary and active by night.

One of the paca's most remarkable features is hidden in its skull: greatly enlarged, hollow cheekbones (zygomatic arches) that act as resonating chambers, amplifying the sounds it makes. By grinding its teeth and using these built-in amplifiers, a paca can produce a surprisingly loud, low rumble — an unusual trait among mammals.

Note: details here cover the lowland paca; treat general statements as approximate and verify against authoritative sources.

Habitat & Range

Pacas live across much of the Neotropics, from Mexico through Central America and into South America, in tropical forests and well-vegetated areas, almost always near water — rivers, streams, swamps, and lakes. They shelter by day in burrows (often near water, sometimes with underwater or hidden entrances) and emerge at night to forage along the forest floor.

Diet

The paca is a herbivore that feeds mainly on fallen fruit, along with seeds, leaves, roots, and other plant matter. As a major fruit-eater of the forest floor, it helps disperse seeds — and, like the agouti, it may bury some, contributing to the regeneration of forest trees. Its strong attraction to fallen fruit makes it a familiar visitor beneath fruiting trees.

Behavior

Pacas are nocturnal, mostly solitary, and shy, foraging alone along regular paths and retreating to a burrow by day. They are excellent swimmers and readily take to water to escape danger, diving and hiding beneath the surface. The enlarged, hollow cheekbones that amplify their tooth-grinding rumbles are a striking and unusual adaptation, used in communication and threat displays. Pacas are alert and quick to flee, relying on their burrows, swimming ability, and the cover of darkness to avoid predators such as big cats.

Human Interaction & Conservation

The paca is one of the most prized game animals in the Neotropics, widely hunted for its meat, which is highly regarded across much of its range, and it is increasingly raised in managed or farmed settings in some areas. The lowland paca remains relatively widespread and is not currently considered globally threatened overall, though heavy hunting and habitat loss can deplete local populations. As an important seed-disperser, it also matters ecologically. Consult the IUCN Red List for current status.

More photos of the paca