Found only in Peru, Black-breasted Hillstars inhabit puna habitat with shrub and cushion cacti. They also like grassy slopes, rocky areas with fertile soil, and gardens. Males have a sparkling green throat and black undersides bordered by creamy buffy edges. Females are bronzy copper above and grayish brown below; they also lack white at the base of the tail which helps distinguish them from Andean Hillstars (Oreotrochilus estella). Where Black-breasted Hillstars overlap with Andean Hillstars, Black-breasteds tend to be more reclusive and stay low in the vegetation. During the breeding season, pairs nest among rocks or under the roofs of houses.