Genovesa Ground Finch
Geospiza acutirostris
Passeriformes Order – Thraupidae Family
INTRODUCTION:
The Genovesa Ground Finch is not well studied yet, but it is endemic to Genovesa Island in N Galapagos archipelago. This species was previously treated within Sharp-beaked Ground Finch – Geospiza difficilis, but it requires now species status. It is part of the Darwin’s Finches.
The Genovesa population is apparently genetically different, and seems mostly closer to other Geospiza species. So, it is better to reuse the name “acutirostris” for the present species.
The Genovesa Ground Finch differs from G. difficilis by song and habitat type. Genetic analysis indicates that this species is more closely related to Small Ground Finch – Geospiza fuliginosa and Medium Ground Finch – Geospiza fortis than it is to Sharp-beaked Ground Finch.
The Genovesa Ground Finch has restricted range and small population apparently currently stable, but the species is listed as Vulnerable.
DESCRIPTION OF THE BIRD:
The Genovesa Ground Finch (G. acutirostris) may be a species derived from mixed ancestry of hybrid origin. (Lamichhaney et al.)
It resembles other Geospiza finches in plumage pattern, but the scientific name “acutirostris” indicates more pointed bill.
RANGE:
The Genovesa Ground Finch is found only on Genovesa Island, in N Galapagos Islands.
HABITAT:
The Genovesa Ground Finch frequents arid scrub habitat at low elevation.
CALLS AND SONGS:
The Genovesa Ground Finch has different song, due to the more pointed bill. The bill shape may lead to more or less pronounced variations in song structure.
BEHAVIOUR IN THE WILD:
The Genovesa Ground Finch feeds on seeds, insects and spiders. It probably takes nectar from cacti too.
The shape of the bill suggests that this species feeds mainly on arthropods found by probing natural holes.
The breeding habits are currently unknown, but referring to habitat type, the Genovesa Ground Finch probably builds its nest in bushes.
It is resident on Genovesa Island where it occupies an area of about 15 km².
REPRODUCTION OF THIS SPECIES:
The Darwin’s Finches usually breed during the rainfall, when insects are abundant.
The clutch usually includes 2-4 eggs. The incubation lasts 11-12 days. The chicks are fed by both parents and fledge about 12-15 days after hatching.
PROTECTION / THREATS / STATUS:
The Genovesa Ground Finch has restricted range and small population, making it vulnerable to invasive predators and disease.
The population is roughly estimated and placed in the band 250/999 mature individuals. It is apparently stable.
But currently, the Genovesa Ground Finch is listed as Vulnerable.
Fr: Géospize de Genovesa
Ang: Genovesa Ground Finch
All: Genovesagrundfink
Esp: Pinzón de Darwin de Genovesa picofino picofino
Nd: Genovesagrondvink
Sd: genovesadarwinfink
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
Wikipedia, the free encyclopaedia
Neotropical Birds – Cornell Lab of Ornithology
Rapid hybrid speciation in Darwin’s finches
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