VU
Large Tree-finch Geospiza psittacula



Taxonomy

Taxonomic note

Geospiza psittacula (del Hoyo and Collar 2016) was previously placed in the genus Camarhynchus following SACC (2005 & updates); Sibley & Monroe (1990, 1993); Stotz et al. (1996).

 

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.
SACC. 2005 and updates. A classification of the bird species of South America. Available at: https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm.

IUCN Red List criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - A2bce+3bce+4bce

Red List history
Year Category Criteria
2021 Vulnerable A2bce+3bce+4bce
2016 Vulnerable A2be+3be+4be
2015 Vulnerable A2be+3be+4be
2012 Least Concern
2009 Least Concern
2008 Least Concern
2004 Least Concern
2000 Lower Risk/Least Concern
1994 Lower Risk/Least Concern
1988 Lower Risk/Least Concern
Species attributes

Migratory status not a migrant Forest dependency high
Land-mass type Average mass -
Range

Estimate Data quality
Extent of Occurrence (breeding/resident) 26,500 km2 medium
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size 20000-49999 mature individuals medium suspected 2020
Population trend decreasing - inferred 2016-2026
Rate of change over the past 10 years/3 generations (longer of the two periods) 30-49% - - -
Rate of change over the future 10 years/3 generations (longer of the two periods) 30-49% - - -
Rate of change over the past & future 10 years/3 generations (longer of the two periods) 30-49% - - -
Generation length 3.1 years - - -

Population justification: The global population size has not been quantified, but this species is described as 'uncommon' in at least parts of its range (Stotz et al. 1996). On the island of Santa Cruz its population has been estimated at 9,000 singing males (Dvorak et al. 2012). However no data exists for the islands of Isabela and Santiago. Tentatively, the population is here placed in the band 20,000-49,999 mature individuals.

Trend justification: The population is assumed to be decreasing rapidly. On the island of Santa Cruz, the species reportedly declined significantly in the dry zone between 1997 and 2010, but not in the Scalesia zone (Dvorak et al. 2012). Habitat alteration, introduced pathogens and parasites and changes in insect availability may have contributed to declines. On the islands of Isabela and Santiago, where native forest has also been degraded by introduced herbivores, population declines are also suspected (Dvorak et al. 2012). In the agricultural zone on Santa Cruz, the relative abundance of this species declined from 0.8 in 1997 to 0.7 in 2010 and 0.38 in 2019 (Geladi et al. 2021). The overall rate of decline is therefore here tentatively placed in the band 30-49% over ten years (see also Freile et al. 2019). In view of ongoing threats, declines are suspected to continue at the same rate into the future.


Country/territory distribution
Country/Territory Presence Origin Resident Breeding visitor Non-breeding visitor Passage migrant
Ecuador extant native yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Ecuador Isla Floreana
Ecuador Isla San Cristóbal
Ecuador Puerto Ayora
Ecuador Tierras altas de Isabela
Ecuador Tierras altas de Santa Cruz
Ecuador Tierras altas de Santiago

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Dry suitable resident
Forest Subtropical/Tropical Moist Montane major resident
Altitude 300 - 700 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Climate change & severe weather Droughts Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Indirect ecosystem effects, Ecosystem degradation
Climate change & severe weather Habitat shifting & alteration Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Indirect ecosystem effects, Ecosystem degradation, Ecosystem conversion
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Canis familiaris Timing Scope Severity Impact
Ongoing Minority (<50%) Causing/Could cause fluctuations Low Impact: 5
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Felis catus Timing Scope Severity Impact
Ongoing Minority (<50%) Causing/Could cause fluctuations Low Impact: 5
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Named species Timing Scope Severity Impact
Ongoing Minority (<50%) Causing/Could cause fluctuations Low Impact: 5
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Philornis downsi Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Unspecified species Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Indirect ecosystem effects, Ecosystem degradation
Invasive and other problematic species, genes & diseases Viral/prion-induced diseases - Avipoxvirus Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Species mortality
Pollution Agricultural & forestry effluents - Herbicides and pesticides Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Indirect ecosystem effects
Residential & commercial development Housing & urban areas Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Transportation & service corridors Roads & railroads Timing Scope Severity Impact
Ongoing Minority (<50%) Causing/Could cause fluctuations Low Impact: 5
Stresses
Species mortality

Recommended citation
BirdLife International (2024) Species factsheet: Large Tree-finch Geospiza psittacula. Downloaded from https://datazone.birdlife.org/species/factsheet/large-tree-finch-geospiza-psittacula on 23/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 23/12/2024.