The Sharp-beaked Ground Finch (Geospiza difficilis) is a species of bird

Bird

Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

 in the Darwin's finch group of the tanager

Tanager

The tanagers comprise the bird family Thraupidae, in the order Passeriformes. The family has an American distribution.There were traditionally about 240 species of tanagers, but the taxonomic treatment of this family's members is currently in a state of flux...

 family Thraupidae.
This rather small, slender-billed bird is endemic to the Galápagos Islands

Galápagos Islands

The Galápagos Islands are an archipelago of volcanic islands distributed around the equator in the Pacific Ocean, west of continental Ecuador, of which they are a part.The Galápagos Islands and its surrounding waters form an Ecuadorian province, a national park, and a...

, where found on Fernandina

Fernandina Island

Fernandina Island is the third largest, and youngest, island of the Galápagos Islands. Like the others, the island was formed by the Galápagos hotspot...

, Santiago

Santiago Island (Galápagos)

Santiago Island is an island of the Galápagos Islands. It is also known as San Salvador, named after the first island discovered by Columbus in the Caribbean Sea , or as James Island. The island, which consists of two overlapping volcanoes, has an area of 585 km² and a maximum altitude of...

, Pinta

Pinta Island

Pinta Island is an island located in the Galapagos Islands group, Ecuador. It has an area of 60 km² and a maximum altitude of 777 meters....

, Genovesa

Genovesa Island

Genovesa Island is a shield volcano in the Galápagos Islands in the eastern Pacific Ocean. The island occupies about , and its maximum elevation is . The horse-shoe shaped island has a volcanic caldera whose wall has collapsed, forming the Great Darwin Bay, surrounded by cliffs...

, Darwin

Darwin Island

Darwin Island is named in honor of Charles Darwin, and is among the smallest in the Galapagos Archipelago with an area of just one square kilometer. With no dry landing sites, Darwin Island's main attractions are found in the Pacific Ocean, which is teeming with a spectacular variety of marine life...

 and Wolf

Wolf Island

Wolf Island or Wenman Island is a small island in the Galapagos Islands and was named after the German geologist Theodor Wolf, who also has the volcano Wolf on Isabela Island named after him...

. On the first three islands, it breeds in the humid highlands and disperses afterwards, but on the remaining smaller and lower islands the Sharp-beaked Ground Finch is found in the arid zone year-round. Formerly it was also present in the highlands of several other islands, and it is possible it still occurs on Isabela.

The subspecies

Subspecies

Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...

 on the islands of Darwin and Wolf has gained a level of notoriety due to its habit of feeding on blood of large birds, notably boobies

Booby

A booby is a seabird in the genus Sula, part of the Sulidae family. Boobies are closely related to the gannets , which were formerly included in Sula.-Description:...

, gaining it the common name Vampire Finch

Vampire Finch

The Vampire Finch is a small bird native to the Galápagos Islands. It is a very distinct subspecies of the Sharp-beaked Ground Finch endemic to Wolf and Darwin Islands....

. Other subspecies do not exhibit this behavior, insteading feeding mainly on insects.