The Black Siskin is a small finch of 12/13 centimeters. Its livery is characterized by its black color, except for the large wing mirrors, the central remiges and the undertail which are sulfur yellow, as well as the area of the cloaca which has white feathers. The sexual dimorphism is practically absent, the females tend to have less color than the males, and rarely yellowish shades also on the lower abdomen.

Habitat: rocky areas above the 3500 meters of altitude in Bolivia, but also in Chile, Peru and Argentina.

Feeding: granivorous nourishes of small seeds of herbaceous and bushy plants, but showing also to like berries, buds, leaflets and sporadically also insects.