The vicuña (Vicugna vicugna) is a wild South American camelid belonging to the family Camelidae, which also includes llamas, alpacas, guanacos and camels. Endemic to the high Andes, its range stretches across Peru, Bolivia, Argentina, Chile and southern Ecuador, primarily occupying puna and páramo grasslands at elevations of 3,200–5,000 m. Vicuñas are the smallest camelids, characterized by a slender body, long neck, and a fine, crimped wool that is among the finest natural fibers in the world (average fiber diameter 12–14 µm). Their coat is a reddish‑brown on the back with a white underbelly and a distinctive black facial mask. Historically driven to the brink of extinction by over‑hunting for their wool, intensive conservation programs and legal protection have allowed populations to rebound, leading the IUCN to list the species as Least Concern. Today, vicuñas play a keystone role in Andean ecosystems, influencing plant community composition through selective grazing and serving as prey for Andean predators such as pumas and Andean foxes.

Vicuñas live in a hierarchical social system composed of small family units (one dominant male, several females, and their offspring) that aggregate into larger herds of up to several hundred individuals during the dry season. They are diurnal, spending daylight hours grazing on high‑altitude grasses and resting in sheltered depressions at night. Territoriality is expressed through scent marking with pre‑orbital glands and occasional low‑frequency vocalizations, especially during the breeding season. When threatened, individuals emit a sharp alarm call and flee in a coordinated, zig‑zag pattern that exploits their exceptional agility on steep terrain. Seasonal migrations are modest, generally limited to a few kilometers to track the availability of nutritious forage across the puna landscape.

Vicuñas are strict herbivores that specialize in grazing on high‑altitude grasses, forbs, and low‑lying shrubs such as Festuca, Stipa, and Azorella species. Their diet is low in protein and water content, so they consume up to 2–3 % of their body weight daily, selecting the most nutritious parts of plants during the early morning dew period. They have a highly efficient rumen that ferments fibrous material, allowing them to extract sufficient nutrients from the sparse puna vegetation. During the dry season, vicuñas expand their foraging range to include more woody browse, and they can survive periods of limited forage by reducing metabolic rate and relying on fat reserves stored in the hump. Their selective grazing helps maintain plant diversity and prevents over‑exploitation of any single species.

Sexual maturity is reached at 2–3 years for females and 3–4 years for males. Breeding is seasonal, occurring primarily between October and December, coinciding with the onset of the Andean spring when forage quality improves. After a gestation period of approximately 335 days, females give birth to a single cria; twins are extremely rare. Newborns are precocial, standing within an hour of birth and able to follow the mother to grazing sites within 24 hours. The mother nurses the cria for about three months, after which the young are weaned but remain with the family group for up to two years, learning foraging techniques and predator avoidance. Males may establish temporary harems during the breeding season, but dominant males often defend territories rather than maintain permanent harems.

The IUCN classifies the vicuña as Least Concern, with an estimated global population of 350,000–400,000 mature individuals as of 2022. Nevertheless, the species faces ongoing threats that could reverse recent gains. Habitat degradation from mining, road construction, and expanding agriculture fragments the high‑altitude grasslands they depend on. Competition with domestic livestock, especially sheep and llamas, reduces available forage and can lead to over‑grazing. Although commercial poaching for wool has been largely curtailed by strict regulations and community‑based management, illegal hunting persists in remote areas. Climate change poses a long‑term risk by altering precipitation patterns and elevating the treeline, potentially reducing suitable puna habitat. Conservation initiatives such as the Vicuña Management Plan in Peru and community‑run sustainable wool cooperatives have helped stabilize populations, but continued monitoring and habitat protection are essential.

• Vicuña wool is up to three times finer than cashmere, making it one of the most valuable natural fibers.
• The species was nearly extinct in the 1960s, with fewer than 5,000 individuals remaining.
• Vicuñas can run at speeds of up to 55 km/h (34 mph) on steep, rocky slopes.
• Their blood contains a high concentration of hemoglobin, an adaptation to low‑oxygen environments above 4,000 m.
• Indigenous Andean communities have a centuries‑old tradition of “chaccu” – a communal round‑up to shear vicuñas sustainably.