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

Taxonomic note

Geospiza heliobates (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(ii,iii,v); C2a(i,ii); D	A2bce; B1ab(ii,iii,v)+2ab(ii,iii,v); C2a(i,ii); D	A2bce; B1ab(ii,iii,v)+2ab(ii,iii,v); C2a(i,ii); D1+2

Red List history

Year	Category	Criteria
2021	Critically Endangered	B1ab(ii,iii,v); C2a(i,ii); D
2018	Critically Endangered	B1ab(i,ii,iv,v)+2ab(i,ii,iv,v); C2a(i); D
2016	Critically Endangered	B1ab(i,ii,iv,v)+2ab(i,ii,iv,v); C2a(i); D
2015	Critically Endangered	B1ab(i,ii,iv,v)+2ab(i,ii,iv,v); C2a(i); D
2013	Critically Endangered	B1ab(i,ii,iv,v)+2ab(i,ii,iv,v); C2a(i); D
2012	Critically Endangered	B1ab(i,ii,iv)+2ab(i,ii,iv);D
2010	Critically Endangered	B1a+b(i,ii,iv,v); B2a+b(i,ii,iv,v); C2a(i)
2009	Critically Endangered	B1a+b(i,ii,iv,v); B2a+b(i,ii,iv,v)
2008	Critically Endangered
2004	Critically Endangered
2000	Critically Endangered
1996	Endangered
1994	Endangered
1988	Threatened

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	16 km2	medium
Area of Occupancy (breeding/resident)	28 km2	medium
Number of locations	1	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	20-40 mature individuals	medium	estimated	2019
Population trend	decreasing	medium	estimated	-
Rate of change over the past 10 years/3 generations (longer of the two periods)	50%	-	-	-
Generation length	3 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The population has not been recorded to number greater than 20 breeding pairs in any year since 2009, falling to a low of just 13 territorial pairs in 2019, of which just 10 bred. The population is therefore estimated to comprise between 20 and 40 mature individuals.
A further 19-23 territorial males without female partners are typically recorded each year in addition to the breeding pairs detailed, a result of rainfall/climatic conditions (Cunninghame et al. 2017, Cunninghame unpubl. data). In 2019, territory and nesting surveys revealed 13 territorial pairs (of which 10 bred), 19 lone territorial males, ~20 additional individuals and 5 newly fledged nestlings, but due to the cryptic nature of juvenile and non-breeding individuals, it is likely that a small percentage of the Mangrove Finch population remains undetected (Cunninghame unpubl. data). The overall population estimate is therefore thought to number 80-100 individuals (F. Cunninghame in litt. 2020).

Trend justification: In 1997 surveys on Isabela found breeding populations in only two areas, Playa Tortuga Negra and Caleta Black on the north-west coast of the island, with estimated populations of 37 and 21 pairs respectively (Grant and Grant 1997, Vargas 1997); but from 2006 to 2009 territory mapping only revealed a maximum of 27 and 15 pairs (Fessl et al. 2010). Further territory mapping from 2010-2019 has recorded further declines with a maximum of 20 breeding pairs recorded in any year since 2009, falling to a low of just 13 territorial pairs in 2019, of which just 10 bred, although up to 19-23 additional territory holding males with no female partner are typically recorded annually (Cunninghame et al. 2017, Cunninghame unpubl. data). This accounts for a further 50-79% decline over a 10 year period. While intensive conservation management is successful at increasing fledging success, overall breeding pair numbers seem to be continuing to rapidly decline and as such, the species is retained as declining,

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

Country/Territory	IBA Name
Ecuador	Áreas costeras de Fernandina y del occidente de Isabela

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Mangrove Vegetation Above High Tide Level	major	resident
Altitude		Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion
Climate change & severe weather	Droughts	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Slow, Significant Declines		Medium Impact: 7
		Stresses Ecosystem degradation, Species mortality
Climate change & severe weather	Storms & flooding	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Slow, Significant Declines		Low Impact: 4
		Stresses Indirect ecosystem effects, Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Crotophaga ani	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Negligible declines		Medium Impact: 6
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Felis catus	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Negligible declines		Medium Impact: 6
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Geospiza pallida	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Causing/Could cause fluctuations		Medium Impact: 6
		Stresses Hybridisation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Philornis downsi	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Very Rapid Declines		High Impact: 9
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus rattus	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Negligible declines		Medium Impact: 6
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Solenopsis geminata	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Whole (>90%)		Rapid Declines		Past Impact
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Viral/prion-induced diseases - Avipoxvirus	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Rapid Declines		Low Impact: 5
		Stresses Species mortality

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Recommended citation
BirdLife International (2024) Species factsheet: Mangrove Finch Geospiza heliobates. Downloaded from https://datazone.birdlife.org/species/factsheet/mangrove-finch-geospiza-heliobates on 22/11/2024.
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 22/11/2024.