• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

Taxonomic note

Geospiza pauper (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.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
B1ab(v)	B1ab(v)+2ab(v); C2a(ii)	B1ab(v)+2ab(v); C2a(i,ii); D1+2

Red List history

Year	Category	Criteria
2018	Critically Endangered	B1ab(v)
2016	Critically Endangered	B1ab(v)
2015	Critically Endangered	B1ab(v)
2013	Critically Endangered	B1ab(v)
2012	Critically Endangered	B1ab(v)
2010	Critically Endangered	B1a+b(v)
2009	Critically Endangered	B1a+b(v)
2008	Vulnerable
2004	Vulnerable
2000	Vulnerable
1994	Lower Risk/Near Threatened
1988	Threatened

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	30 km2	medium
Area of Occupancy (breeding/resident)	23 km2	good
Number of locations	1	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	600-1700 mature individuals	good	estimated	2008
Population trend	decreasing	medium	estimated	1999-2010
Generation length	3.8 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The maximum size of the population was estimated at 1,660 individuals in 2008. It is best placed in the band 1,000-2,499 individuals, equating to 667-1,666 mature individuals, rounded here to 600-1,700 mature individuals.

Trend justification: Numbers in 2008 were 39% of those recorded in 2004, indicating a decline outside the range expected for a fluctuating but stable population. Density fell from 154 birds/km² in 2004 to 60 birds/km² in 2008 at Cerro Pajas, and it is significantly less common now than it was 50 to 100 years ago (O'Connor et al. 2010a).

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

Country/Territory	IBA Name
Ecuador	Isla Floreana

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Dry	major	resident
Forest	Subtropical/Tropical Moist Montane	major	resident
Shrubland	Subtropical/Tropical Moist	major	resident
Altitude	0 - 640 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Small-holder farming	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Ecosystem degradation, Ecosystem conversion
Climate change & severe weather	Habitat shifting & alteration	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Unknown		Unknown
		Stresses Indirect ecosystem effects, Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Bos taurus	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Canis familiaris	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Equus asinus	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Felis catus	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		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%)		Rapid Declines		Medium Impact: 7
		Stresses Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus rattus	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Sus domesticus	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Geospiza parvula	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Unknown		Unknown
		Stresses Hybridisation
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Geospiza psittacula	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Unknown		Unknown
		Stresses Hybridisation
Invasive and other problematic species, genes & diseases	Viral/prion-induced diseases - Avipoxvirus	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Rapid Declines		Medium Impact: 7
		Stresses Reduced reproductive success, Species mortality

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Recommended citation
BirdLife International (2024) Species factsheet: Medium Tree-finch Geospiza pauper. Downloaded from https://datazone.birdlife.org/species/factsheet/medium-tree-finch-geospiza-pauper 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.