Vampire Ground Finch
Geospiza septentrionalis
Passeriformes Order – Thraupidae Family
INTRODUCTION:
The Vampire Ground Finch was formerly a subspecies of the Sharp-beaked Ground Finch – Geospiza difficilis, but it is now a full species. It is part of the Darwin’s Finches.
This species is found on two small islands in NW Galapagos Islands. It differs from G. difficilis by some details of plumage, but mainly by longer and more pointed bill.
This species is known for its habit of drinking blood from seabirds by pecking at bases of feathers. This behaviour gives the bird its name.
Like all Darwin’s Finches, the Vampire Ground Finch is primarily threatened by invasive species. However, the small population is suspected to be stable, but the species is currently listed as Vulnerable.
DESCRIPTION OF THE BIRD:
Biometrics:
Weight: 20 g
The Vampire Ground Finch is larger than G. difficilis which is 11-12 centimetres long.
The adult male is black to greyish-black overall with unusual pale markings on the undertail-coverts. The wings are longer too.
The adult female has dull greyish plumage with brown streaking, but she is darker than female of G. difficilis. Two cinnamon wingbars can be seen on the upperwings.
The immature resembles female.
The most distinctive physical feature is the bill. It is longer and more sharply pointed, with more curved culmen and almost a small hooked tip. The colour varies from black to pale orange, depending on the season.
The eyes are blackish with grey eyering. Legs and feet are black.
RANGE:
The Vampire Ground Finch is endemic to Darwin and Wolf Islands, two tiny islands in extreme NO Galapagos archipelago.
HABITAT:
The Vampire Ground Finch frequents deciduous forests with open areas of low vegetation.
CALLS AND SONGS:
The Vampire Ground Finch of Wolf Island has a melodious song, whereas the birds of Darwin Island utter a mostly buzzing song.
However, whistling calls can be heard on both islands, but a drawn-out, buzzing call is reported only on Wolf Island.
BEHAVIOUR IN THE WILD:
The Vampire Ground Finch feeds primarily on seeds and insects, and mostly seeds. It also takes nectar from cacti Opuntia (Opuntia echios) and flowers, at least on Wolf Island. It also consumes bird eggs.
But the scarcity of fresh water on these islands led the birds to the blood-drinking behaviour, a very peculiar habit of the Vampire Ground Finch.
The long, sharply pointed bill allows the bird to peck at bases of feathers of large seabirds, often the Masked Booby - Sula dactylatra. It usually starts where a feather is growing, and licks up the blood as it begins to flow. It drinks the blood as supplementary food, when seeds and insects are less abundant.
This behaviour could have evolved from the habit of picking parasites from booby’s feathers, and the seabirds usually appreciate this behaviour.
The Vampire Ground Finch is gregarious and often feeds in groups.
It is typically monogamous. The male is territorial and guards the nesting territory. The nesting period occurs during the rainfall, when insects are abundant.
The Vampire Ground Finch is resident and only performs short-distance flights while foraging.
REPRODUCTION OF THIS SPECIES:
The breeding season takes place during abundant rainfall.
The Vampire Ground Finch builds a small, dome-shaped nest in cactus or bush.
The female lays 3 eggs. The incubation lasts 12 days. Both parents feed the chicks, especially with insects. The young fledge 14-15 days after hatching.
PROTECTION / THREATS / STATUS:
The Vampire Ground Finch has restricted range on two tiny islands in Galapagos archipelago.
The species is threatened by invasive species, including Philornis downsi, a species of fly able to reduce fledgling success.
The population is placed in the band 250/999 mature individuals, and is suspected to be stable.
But currently, the Vampire Ground Finch is listed as Vulnerable.
Fr: Géospize vampire
Ang: Vampire Ground Finch
All: Vampirgrundfink
Esp: Pinzón de Darwin chupasangre
Nd: Vampiergrondvink
Sd: vampyrdarwinfink
Text by Nicole Bouglouan
Sources :
HANDBOOK OF THE BIRDS OF THE WORLD Vol 16 by Josep del Hoyo- Andrew Elliot-David Christie – Lynx Edicions – ISBN: 9788496553781
The IUCN Red List of Threatened Species
Proposal for English names for recently split Darwin’s finches
Beaks, Adaptation, and Vocal Evolution in Darwin's Finches
Galapagos Islands.com - The Vampire Finch
Discovering Galapagos Connect - The Blood Drinking Vampire Finch
Wikipedia, the free encyclopaedia
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