Galapagos Species Database

The Galapagos Species Database shares the information about the species from our Natural History Collections.

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Geospiza fortis Gould, 1837

Pinzón Terrestre Mediano, Pinzón mediano de tierra, Medium Ground Finch

Medium Ground Finch in Floreana, Galapagos. Photo: Michael Dvorak, CDF.
Medium Ground Finch in Floreana, Galapagos. Photo: Michael Dvorak, CDF.

In Santa Cruz, there are small beaked and large beaked birds; the latter can be confused with large ground finches, but beak depth is less and overall impression is smaller than large ground finch.

Threats Main threats are probably rats and disease. It is known to be affected by the parasitic fly Philornis downsi that causes heavy chick mortality.

Taxonomy

Domain
Eukaryota

Kingdom
Animalia

Phylum
Chordata

Class
Aves

Order
Passeriformes

Family
Thraupidae

Genus
Geospiza

Species
fortis

Taxon category: Accepted

Syn: Geospiza dubia (Gould, 1837); Geospiza dentirostris (Gould, 1837).

Taxon origin: Endemic

Status

Least concern

Ecology

Feeding type: Granivorous

Seed and flowers

Feeding preferences: Mainly seed eater but visits also flowers and may be an important pollen vector.

Trophic role: Herbivorous

Reproduction mode: Exclusively sexual

Reproductive biology: Male displays in front of a dome shape nest, often built in Opuntia cacti. Only females are incubating (three to five eggs), both feed the chicks.

Distribution

Map of specimen collection localities or observation records for this species in our collections database.

Distribution: Widespread on all main islands except Darwin, Genovesa, and Wolf (where one was collected in 1906). In 1905-1906 fifteen non-breeding birds were collected on Española, but they may be stragglers or part of a now-extinct population.

References

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You are welcome to download and use the information found in this page, acknowledging the origin of the data.
This page should be cited as follows:
"Galapagos Species Database, Geospiza fortis", dataZone. Charles Darwin Foundation, https://datazone.darwinfoundation.org/en/checklist/?species=5094. Accessed 24 April 2024.