 This large hummingbird, about long, is thought to number only about 500 individuals.The other endemic bird species are the Juan Fernández tit-tyrant ("Anairetes fernandezianus") of Robinson Crusoe Island, and the Masafuera rayadito ("Aphrastura masafuerae") of Alejandro Selkirk Island.The islands support the entire known breeding populations of two petrel species, Stejneger's Petrel "Pterodroma longirostris" (IUCN status VU) and the Juan Fernandez Petrel "Pterodroma externa" (IUCN status VU).