Viscachas are rodents in the family Chinchillidae, making them close relatives of the chinchilla. They are native exclusively to South America, where they have adapted to two vastly different environments. The term “viscacha” refers to several distinct species, split between the high-altitude Andes Mountains and the extensive, low-lying grasslands of the plains.
The Major Viscacha Species
The viscacha family is divided into two distinct genera: the Plains Viscacha and the Mountain Viscachas. The Plains Viscacha (Lagostomus maximus) is the sole species in its genus. It is the largest member of the chinchilla family, with males weighing up to 8 kilograms, and is characterized by a blunt head, robust forelimbs for digging, and a short tail (15 to 20 cm).
Mountain Viscachas (genus Lagidium) include several species, such as the Southern and Northern Viscachas. These species are smaller, typically weighing up to 3 kilograms, and feature long, bushy tails (30 to 40 cm) used for balance on rocky terrain. These physical differences reflect distinct shelter strategies: plains species are specialized burrowers, while mountain species are rock dwellers.
Habitat and Range of the Plains Viscacha
The Plains Viscacha (Lagostomus maximus) is found across the low-elevation grasslands, scrublands, and semi-arid regions of the continent’s interior. Its geographic range covers central and northern Argentina, extending into southern Bolivia and southwestern Paraguay. This environment includes the flat, temperate grasslands of the Pampas region and the dry savannas of the Gran Chaco. While found up to nearly 3,000 meters, it primarily inhabits lowlands where the soil structure is suitable for its lifestyle.
The Plains Viscacha relies entirely on its massive, complex communal burrow system, known as a viscachera. These elaborate warrens consist of interconnecting tunnels and chambers, providing protection from predators and the elements. The species’ distribution is dictated by its reliance on soft, workable soil, which must be easy to excavate and maintain. A single system can cover up to 600 square meters and endure for centuries, housing colonies of up to 50 members. Plains Viscachas are nocturnal, emerging at dusk to forage, and they mark entrances with collected debris like sticks, stones, and bones.
Habitat and Range of the Mountain Viscachas
The Mountain Viscachas (genus Lagidium) inhabit the harsh, high-altitude environments of the Andes Mountains, a range that spans from central Peru southward through Bolivia, Chile, and Argentina. These species are adapted to the arid, rocky terrain found above the timberline, typically living at elevations between 3,000 and 5,000 meters (10,000 to 16,000 feet). This extreme habitat is characterized by steep slopes, rocky outcrops, and thin air.
Unlike their plains relatives, mountain viscachas are poor diggers and do not construct burrows. They rely instead on the natural architecture of their environment, utilizing existing crevices, caves, and rock piles for shelter. Colonies are found among cliffs and large boulder fields, allowing quick retreat from predators. These viscachas are diurnal, often seen basking on exposed rocks to regulate body temperature in the cold climate. Their dense fur provides insulation, and their agility allows them to leap effectively across the uneven landscape.