Overview
The Plains Viscacha (Lagostomus maximus), celebrated across Argentina as the ‘Vizcacha de las Pampas’, is the heavy-bodied, mustachioed colonial engineer of South America’s vast grasslands. Belonging to the chinchilla family Chinchillidae, this imposing, nocturnal rodent lives in sprawling subterranean mega-cities called ‘viscacheras’ that have been continuously occupied and expanded by generations of viscachas for centuries. Renowned for its bold black-and-white facial stripes and an obsessive, hoarding compulsion to pile strange heavy objects around its burrow entrances, it is a charismatic icon of the Argentine Pampas.
Biology and Physical Characteristics
Lagostomus maximus is a robust, stocky rodent with dramatic sexual dimorphism: mature males are nearly twice the size of females and develop massive, blunt jowls. Its coat is soft, dense, and grizzled brownish-grey across the back and flanks, fading to pure white on the belly. Its most diagnostic hallmark is its magnificent, badger-like facial mask: two bold, horizontal black bands run across its face—one through the eyes and one across the muzzle—separated by stark, snowy-white stripes. Below its wide nostrils, it sports a formidable, drooping mustache of stiff black vibrissae. Its forelimbs are short with four strong digging claws, while its muscular hind limbs bear three toes armed with heavy hooved claws that deliver powerful leaping propulsion.
Behavior and Ecology
Deeply social and strictly nocturnal, Plains Viscachas live in communal clans of twenty to fifty individuals that occupy a central warren system featuring dozens of interconnected tunnels and cavernous sleeping chambers. At dusk, the dominant male (‘el vizcachón’) emerges first, sitting majestically atop the burrow mound to survey the plains before giving a low grunting signal that it is safe for females and juveniles to emerge. Viscachas exhibit a bizarre, obsessive hoarding instinct: they meticulously collect and pile bones, rocks, dried cattle dung, bleached branches, and human artifacts (including discarded boots, watches, and silverware) around their burrow mouths, creating defensive stone barricades that deter burrow-invading predators like pumas and Geoffroy’s cats.
Conservation and Human Impact
The Plains Viscacha is classified as Least Concern on the IUCN Red List. Due to its historical abundance across the Argentine plains, it remains widespread. However, because its massive burrow mounds and extensive grazing were perceived as hazards to livestock and agricultural crops, it was heavily persecuted and systematically eradicated across vast swathes of the fertile Pampas during the 20th century. Today, wild populations remain robust within protected national parks, such as El Palmar National Park and Chaco National Park, and throughout the semi-arid monte scrub of western Argentina.
Interesting Factoid
The Plains Viscacha is the world’s most obsessive hoarder—it collects heavy stones, animal bones, horse shoes, and even watches and silverware dropped by ranchers, building giant treasure mounds over five feet tall around its front door!