Green-headed hillstar
The green-headed hillstar is a species of hummingbird found in the Andes in far southern Ecuador and northern and central Peru in alpine grassland and scrub at altitudes of.
It was traditionally considered a subspecies of the Andean hillstar, Oreotrochilus estella, but it is increasingly treated as a separate species based on differences in genetics and plumage. It is more closely related to the blue-throated hillstar and black-breasted hillstar than the Andean hillstar. Females of these are very similar, but the males are easily separated. The male blue-throated hillstar has a blue throat and the male black-breasted hillstar has almost entirely black underparts. Compared to the Andean hillstar, the male green-headed hillstar has a brighter green head and a black line to the central underparts.
The binomial name commemorates Polish ornithologist Jan Sztolcman.
