Description: High-Andean siskin measuring 11–13 cm, very dark, almost entirely black, with bright yellow on the lower belly, undertail coverts, base of the tail, and a well-marked yellow wing patch. It is the darkest of all Spinus, the only one with an entirely black rump, which makes it easy to distinguish from sympatric species. Wings black with yellow bases on primaries and secondaries. Tail dark. Bill short and conical. Female similar but duller, with less glossy black and a more extensive yellow on the belly, sometimes reaching the chest. Juvenile blackish or dark brown with a pinkish bill and buff wingbars; belly pale yellowish.
Geographic distribution: Generally a species of the high Andes, from central Peru south into Bolivia, northern Chile, and northwestern Argentina, present in Jujuy, Salta, Tucumán, Catamarca, and La Rioja. Recorded south to Mendoza in Andean areas. In Tucumán it is very common above the Yungas in high grasslands (Cumbres Calchaquíes – Aconquija). Found mainly between 2900–4500 m in Argentina and Chile, with records from 1800 m in more austral areas and winter descents to 700–1400 m.
Habitat: High grasslands on rocky slopes, puna steppes, shrubby ravines, stony areas, and edges of high-Andean wetlands. Also uses areas near rural outposts, stone corrals, and high-altitude settlements. In winter it partially descends to lower ravines and arid foothills.
Behavior: Wary but active, performing low, direct flights between rocks and shrubs. During the breeding season it moves in pairs; the rest of the year it forms groups. Song is fast and high-pitched with variations and occasional mimicry; flight call and nasal alarm notes.
Diet: Seeds of low plants and shrubs, tender shoots, and to a lesser extent insects. Feeds on the ground or on low vegetation, moving in pairs and small groups; outside the breeding season forms larger flocks, sometimes associating with other siskins.
Reproduction: Builds a nest in low shrubs using plant fibers and wool.
Conservation status: Not threatened. Locally common in suitable habitats, but sensitive to degradation of high-Andean grasslands and intensive grazing, and locally affected by wildlife trafficking.
Authors of this compilation: Diego Carus and Maria Belén Dri – 06/12/2025