{{Short description|Species of bird}} {{Speciesbox | name = Vampire ground finch | image = {{Easy CSS image crop|Image=Vampire finch (4229090408).jpg|desired_width=250|crop_left_perc=35|crop_right_perc=20|crop_top_perc=35}} | status = VU | status_system = IUCN3.1 | status_ref = <ref name=iucn>{{cite iucn |author=BirdLife International|year= 2022 |title= ''Geospiza septentrionalis'' |article-number=e.T103815245A182414024 |doi=10.2305/IUCN.UK.2022-1.RLTS.T103815245A182414024.en |access-date=16 May 2024}}</ref> | genus = Geospiza | species = septentrionalis | authority = Rothschild & Hartert, 1899 | synonyms = ''Geospiza difficilis septentrionalis''<ref name="grant">'''Grant''', Peter R.; Grant, B. Rosemary & Petren, Kenneth (2000). The allopatric phase of speciation: the sharp-beaked ground finch (''Geospiza difficilis'') on the Galápagos islands. ''Biol. J. Linn. Soc.'' '''69'''(3): 287–317. {{doi|10.1006/bijl.1999.0382}}</ref><ref>Rothschild, W. and E. Hartert. (1899). A Review of the Ornithology of the Galapagos Islands. With Notes on the Webster-Harris Expedition. ''Novitates Zoologicae'' Vol. VI, No. 2, pp. 85-205, 2 plates.</ref> | range_map = Geospiza septentrionalis map.svg }}

The '''Vampire ground finch''' ('''''Geospiza septentrionalis''''') or '''Vampire finch''' is a small bird native to the Galápagos Islands. A member of the Darwin's finches group, it is known for its unique parasitic behavior of feeding on the blood of other birds. It is endemic to Wolf and Darwin Island. The species was previously considered a very distinct subspecies of the sharp-beaked ground finch (''Geospiza difficilis''),<ref name="grant"/> 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.<ref>{{cite journal|last1=Farrington|first1=Heather|last2=Lawson|first2=Lucinda|last3=Clark|first3=Courtney|last4=Petren|first4=Kenneth|title=The evolutionary history of Darwin's finches: speciation, gene flow, and introgression in a fragmented landscape|journal=Evolution|date=29 July 2014|volume=68|issue=10|pages=2932–2944|doi=10.1111/evo.12484|pmid=24976076|s2cid=205123574}}</ref>

==Description== The vampire finch is sexually dimorphic as typical for its genus, with the males being primarily black and the females grey with brown streaks. It has a lilting song along with a drawn-out, buzzing call on Wolf, a buzzing song on Darwin, and whistling calls on both islands.<ref name="grant" />

==Diet== This bird is most famous for its unusual diet. When alternative sources are scarce, the vampire finch occasionally feeds by drinking the blood of other birds, chiefly the Nazca and blue-footed boobies, pecking at their skin with their sharp beaks until blood is drawn.<ref name="schu">'''Schluter''', Dolph & '''Grant''', Peter R. (1984). Ecological Correlates of Morphological Evolution in a Darwin's Finch, ''Geospiza difficilis''. ''Evolution'' '''38'''(4): 856-869. {{doi|10.2307/2408396}} (HTML abstract and first page image)</ref><ref name=":0">{{Cite journal|last1=Michel|first1=Alice J.|last2=Ward|first2=Lewis M.|last3=Goffredi|first3=Shana K.|last4=Dawson|first4=Katherine S.|last5=Baldassarre|first5=Daniel T.|last6=Brenner|first6=Alec|last7=Gotanda|first7=Kiyoko M.|last8=McCormack|first8=John E.|last9=Mullin|first9=Sean W.|date=2018-09-19|title=The gut of the finch: uniqueness of the gut microbiome of the Galápagos vampire finch|journal=Microbiome|volume=6|issue=1|page=167|doi=10.1186/s40168-018-0555-8|issn=2049-2618|pmc=6146768|pmid=30231937 |doi-access=free |bibcode=2018Micb....6..167M }}</ref> This behaviour may have evolved as a symbiotic relationship, with the finches removing ectoparasites from the boobies' feathers, but has become a parasitic relationship over time.<ref name=":2">{{Cite journal |last=Bowman |first=Robert I. |last2=Billeb |first2=Stephen L. |date=1991 |title=Blood-eating in a Galapagos finch |url=https://www.biodiversitylibrary.org/page/59398626 |journal=Living Bird |volume=4 |pages=29-44}}</ref><ref name=":3">{{Cite web |last=Baldassarre|first=Daniel|last2=Chaves|first2=Jaime|last3=Gotanda|first3=Kiyoko|date=2021-01-15|title=Vampire finches: how little birds in the Galápagos evolved to drink blood|url=https://theconversation.com/vampire-finches-how-little-birds-in-the-galapagos-evolved-to-drink-blood-153010|access-date=2026-04-22|website=The Conversation|language=en-US}}</ref> While boobies will typically swat at pecking finches, several finches may feed on a single booby at once, making defense impractical.<ref name=":2" /><ref>{{Cite news |last=Simon|first=Matt|title=Absurd Creature of the Week: The Tiny Blood-Slurping Bird That Terrorizes the Galapagos|url=https://www.wired.com/2014/07/absurd-creature-of-the-week-vampire-bird/|access-date=2026-04-22|work=Wired|language=en-US|issn=1059-1028}}</ref> The finches also predate the boobies' eggs, making their hosts reluctant to leave their nests to stop the blood-letting.<ref name=":3" /> Guano and leftover fish from other predators additionally serve as diet options.<ref name=":0" />

Vampire ground finches drink more blood during dry seasons when seeds and other prey are scarce, resuming omnivory when the rainy season begins. There were also significant variations in the intestinal microbial community structure between species, with a clear separation between vampire ground finches and other finches. Vampire ground finches have intestinal microbial communities rich in peptostreptococcaceae, similar to vampire bats.<ref name=":1">{{Cite journal |last1=Song |first1=Se Jin |last2=Sander |first2=Jon G. |last3=Baldassarre |first3=Daniel T. |last4=Chaves |first4=Jaime A. |last5=Johnson |first5=Nicholas S. |last6=Piaggio |first6=Antoinette J. |last7=Stuckey |first7=Matthew J. |last8=Nováková |first8=Eva |last9=Metcalf |first9=Jessica L. |last10=Chomel |first10=Bruno B. |last11=Aguilar-Setién |first11=Alvaro |last12=Knight |first12=Rob |last13=McKenzie |first13=Valerie J. |date=2019 |title=Is there convergence of gut microbes in blood-feeding vertebrates? |journal=Philosophical Transactions of the Royal Society B |volume=374 |issue=1777 |pages=374(1777)|doi=10.1098/rstb.2018.0249 |pmid=31154984 |pmc=6560276 }}</ref>

More conventionally for birds, but still unusual among ''Geospiza,'' they also take nectar from Galápagos prickly pear (''Opuntia echios'' var. ''gigantea'') flowers, at least on Wolf Island.<ref name="schu" /> The reason for these peculiar feeding habits is the lack of fresh water on these birds' home islands. Nonetheless, the mainstay of their diet is made up of seeds and invertebrates, like other members of their genus.<ref name="schu" />

==Conservation== The vampire finch is classified as vulnerable by the IUCN based on its very restricted distribution and small population. Conservation efforts primarily involve biosecurity measures and restricted access to Darwin and Wolf islands to prevent the spread of disease and invasive species.<ref name=iucn/>

As of 2022, fewer than 1,000 mature individuals of the vampire ground finch are estimated to inhabit their range. This isolated population makes it vulnerable to potential threats such as the invasive avian vampire fly (''Philornis downsi'') and viruses like the avian pox, though neither of these threats have yet been reported on Wolf or Darwin islands.<ref name=iucn/>

==References== {{Reflist}}

==External links== *{{Commons category inline}} {{Taxonbar|from1=Q1054264|from2=Q55118761}}

Category:Geospiza Category:Endemic birds of the Galápagos Islands Category:Hematophages Category:Parasitic vertebrates Category:Birds described in 1899 Category:Taxa named by Walter Rothschild Category:Taxa named by Ernst Hartert