Family Tanagers (Thraupidae)

Least Concern

Medium Ground-finch (Geospiza fortis)


Taxonomy

French: Géospize à bec moyen German: Mittelgrundfink Spanish: Pinzón de Darwin picomediano
Taxonomy:

Geospiza fortis

Gould

, 1837,

Galapagos Islands

.

Large-scale hybridization with G. magnirostris thought to have occurred on Santa Cruz. Hybridizes rarely with G. fuliginosa and with G. scandens, although on Isla Daphne Mayor N of Santa Cruz recent drought selected against birds with large bills and hybridization with immigrant fuliginosa has led to a further decrease in bill size to point where the two species appear to have fused#R. Monotypic.

Distribution:

Galapagos Is: islands of Pinta, Marchena, Fernandina, Isabela, Santiago, Rábida, Pinzón, Baltra, Santa Cruz, Santa Fe, Floreana and offshore islets, and San Cristóbal.

Descriptive notes

11–12 cm; 18–32 g. A medium-sized ground-finch with relatively thick bill slightly longer than it is deep (bill size variable from island to island, and may... read more

Voice

Classic song a nasal repetition of 2 or 3 notes, “clzee clzee” or “tzeeuu tzeeuu... read more

Habitat

Mostly occurs in scrub and at forest edge. Found at all elevations and in all habitats, but most... read more

Food and feeding

A generalist in diet, made possible by its intermediate and variable bill size. Variety of seeds, fruits and insects. Generally, more than... read more

Breeding

Nest built by male, a sphere with entrance towards top and on side, made from dry grasses and other vegetation. Clutch usually 4 eggs,... read more

Movements

Resident; some upslope movement during non-breeding season.

Status and conservation

Not globally threatened (Least Concern). Abundant and widespread. Present on most islands of the Galapagos Archipelago. Recent increase in prevalence of avian pox in... read more

Recommended citation

Jaramillo, A. & Christie, D.A. (2018). Medium Ground-finch (Geospiza fortis). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/62176 on 21 June 2018).