Andean Hillstar Hummingbird
The Andean Hillstar Hummingbird is found mainly in the high altitude tropical grasslands of Argentina, Bolivia, Chile, Ecuador, and Peru.
The species is generally well adapted to cold nights in the Andes, which it survives by going into a state of torpor and thus reducing its metabolic rate to something like that of hibernation.
Some of the information for this post as well as the photo comes from the website How To Enjoy Hummingbirds. Additional information comes from Wikipedia.