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

Taxonomic source(s)
AERC TAC. 2003. AERC TAC Checklist of bird taxa occurring in Western Palearctic region, 15th Draft. Available at: http://www.aerc.eu/DOCS/Bird_taxa_of_the_WP15.xls.
Cramp, S. and Simmons, K.E.L. (eds). 1977-1994. Handbook of the birds of Europe, the Middle East and Africa. The birds of the western Palearctic. Oxford University Press, Oxford.
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.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	B1ab(ii,iii)+2ab(ii,iii)

Red List history

Year	Category	Criteria
2017	Vulnerable	B1ab(ii,iii)+2ab(ii,iii)
2016	Endangered	B1ab(i,ii,iii)
2012	Endangered	B1ab(i,ii,iii,iv,v)
2008	Endangered	B1a+b(i,ii,iii,iv,v)
2004	Endangered
2000	Endangered
1996	Vulnerable
1994	Vulnerable
1988	Lower Risk/Least Concern

Migratory status	not a migrant	Forest dependency	does not normally occur in forest
Land-mass type		Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	13,300 km2	medium
Area of Occupancy (breeding/resident)	1,300 km2
Number of locations	3	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	1500-2000 mature individuals	poor	estimated	2009
Population trend	unknown	good	-	-
Generation length	4.4 years	-	-	-
Number of subpopulations	3	-	-	-

Population justification: The population was estimated at c.500 pairs in the early 1990s, and was thought to number 1,000-1,500 birds based on its known range in 2007 (C. J. Hazevoet in litt. 2007). However, conservative estimates of 500 pairs on Fogo mean that the total population is likely to be higher, likely numbering 1,500-2,000 mature individuals, roughly equivalent to 2,200-3,000 individuals in total.  Full censuses were never carried on Fogo or Santiago. The numbers on Santiago could be higher than previously thought because the bird is now known to occur in all vegetated areas of the island, whereas in the 1990s it was thought to be absent from the north of the island (H. Batalha in litt. 2016). On Fogo, a volcanic eruption in 2014 does not seem to have affected the extent of area occupied by the bird, but the bird is absent from areas where it had been previously found on the forest of Monte Velha following the forest fire of 2015. However, the size of the birds’ territories is unknown, and could be larger than in closely related species; this means that the numbers estimated based on replies to playbacks may or may not correspond to the actual numbers (in recent surveys, the same colour-ringed bird replied to playback lures from locations that could have considered two adjacent territories [H. Batalha in litt. 2016]). Surveys on S. Nicolau in three occasions in 2014 and 2016 found 12 – 13 territories each time, and the real number is not likely to be much higher.  There are probably a minimum of 20 birds and a maximum of 50 on that island.

Trend justification: Despite the discovery of a large population on Fogo in 2004 and a report from Tarrafal on Santiago, the overall population was suspected to be declining owing to habitat loss, although substantive evidence of this is lacking (C.J. Hazevoet in litt. 2007). The Fogo population favours coffee plantations and introduced crops and the population may yet prove to be stable.

While the population on S. Nicolau seems to have decreased between the time of its discovery, in the 1860s, and the 1920s, the numbers seem to have stabilised, with approximately the same numbers of birds found in 1998, 2004, 2014 and 2016 (H. Batalha in litt. 2016). On Santiago, the bird was considered to be absent from the northern part of the island in the 1980s and 1990s, but currently it can be found in all latitudes (Batalha et al. 2016); it is not clear whether the birds was really absent on the northern part of the island in the 1980s/1990s or were simply undetected, so current population trends are difficult to infer (H. Batalha in litt. 2016), and it is possible that the species may have as much as doubled in population size (C. Hazevoet in litt. 2012).

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

Country/Territory	IBA Name
Cape Verde	Central mountain range of Ilha de São Nicolau
Cape Verde	Pedra Badejo lagoons
Cape Verde	Serra do Pico da Antónia

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Terrestrial	Arable Land	suitable	resident
Artificial/Terrestrial	Arable Land	suitable	resident
Artificial/Terrestrial	Plantations	suitable	resident
Artificial/Terrestrial	Plantations	suitable	resident
Artificial/Terrestrial	Rural Gardens	suitable	resident
Artificial/Terrestrial	Rural Gardens	suitable	resident
Artificial/Terrestrial	Urban Areas	suitable	resident
Artificial/Terrestrial	Urban Areas	suitable	resident
Forest	Subtropical/Tropical Dry	suitable	resident
Shrubland	Subtropical/Tropical Dry	suitable	resident
Shrubland	Subtropical/Tropical Moist	suitable	resident
Shrubland	Subtropical/Tropical Moist	suitable	resident
Wetlands (inland)	Bogs, Marshes, Swamps, Fens, Peatlands	suitable	resident
Wetlands (inland)	Bogs, Marshes, Swamps, Fens, Peatlands	suitable	resident
Altitude	0 - 1384 m	Occasional altitudinal limits

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 Ecosystem degradation
Climate change & severe weather	Storms & flooding	Timing		Scope		Severity		Impact
		Future		Minority (<50%)		Rapid Declines		Low Impact: 4
		Stresses Ecosystem degradation, Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Unspecified species	Timing		Scope		Severity		Impact
		Future		Minority (<50%)		Slow, Significant Declines		Low Impact: 3
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Problematic species/disease of unknown origin - Unspecified species	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Species mortality
Natural system modifications	Fire & fire suppression - Increase in fire frequency/intensity	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Rapid Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion, Species mortality
Other options	Other threat	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Residential & commercial development	Housing & urban areas	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion

Purpose	Scale
Pets/display animals, horticulture	international

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Recommended citation
BirdLife International (2024) Species factsheet: Cape Verde Swamp-warbler Acrocephalus brevipennis. Downloaded from https://datazone.birdlife.org/species/factsheet/cape-verde-swamp-warbler-acrocephalus-brevipennis 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.