Endemic to Wolf and Darwin Island, it was previously considered a very distinct subspecies of the sharp-beaked ground finch (Geospiza difficilis),[2][3] but the International Ornithologists' Union has split the species based on strong genetic evidence that they are not closely related, and divergences in morphology and song.

[4] The vampire finch is sexually dimorphic as typical for its genus, with the males being primarily black and the females grey with brown streaks.

[7] The finches also feed on eggs, stealing them just after they are laid and rolling them (by pushing with their legs and using their beak as a pivot) into rocks until they break.

[8] More conventionally for birds, but still unusual among Geospiza, they also take nectar from Galápagos prickly pear (Opuntia echios var.

[5] The vampire finch is classified as vulnerable by the IUCN based on its very restricted distribution and the impact of invasive species in its habitat.