Bird
Medium Ground-Finch
Geospiza fortisAlso known as Darwin's Medium Ground Finch
Adult males sport pitch-black plumage while females and juveniles display mottled brown streaks, but both possess a stout, multi-purpose crushing bill. Decades of intensive field studies revealed that during severe droughts, natural selection measurably alters average beak dimensions in a single generation to crack tough, woody seeds. Highly opportunistic foragers, these birds hop across volcanic gravel and arid scrub, occasionally even grooming ticks from resting marine iguanas.
EndemicGranivoreSongbird
—observations
—countries
—peak records
Least ConcernConservation statusIUCN Red List categoriesLCNTVUENCREWEXLeast ConcernRed List categories, explained →
Diet & preyPuncture vine seeds, Caterpillars, Opuntia cactus seeds
Predators
- Galápagos Hawk
- Short-eared Owl
- Feral cat
ThreatsInvasive avian vampire flies, introduced predators, and climatic shifts
HabitatsArid lowland scrub, tropical dry shrubland, and littoral zones
Life span10–16 years
Classification
- FamilyThraupidae
- SpeciesGeospiza fortis
Range data is not available yet.
Interaction riskLow
- Low
- Moderate
- High
- Very high
- Why interaction risk is low
- Safe to observe at a normal distance.
Responsible observation
- Trail Etiquette: Remain strictly on designated park pathways to avoid trampling ground nests in the scrub.
- Beak Observation: Use binoculars to examine beak depth, which varies visibly among local birds.
- Water Sources: Watch near fresh puddle seepages or shaded crevices where birds gather to drink.
Predator (c) Tristan Jobin, some rights reserved (CC BY), uploaded by Tristan Jobin · cc-by
Image unavailableParasite Prey Close Relative 
Close Relative (c) Raúl A. Ruiz M., some rights reserved (CC BY) · cc-byClose Relative
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