CR
Raso Lark Alauda razae



Taxonomy

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.

IUCN Red List criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
B1ac(iv) B1ac(iv)+2ac(iv) B1ac(iv)+2ac(iv); D1+2

Red List history
Year Category Criteria
2021 Critically Endangered B1ac(iv)
2018 Critically Endangered B1ac(iv)+2ac(iv)
2016 Critically Endangered B1ac(iv)+2ac(iv)
2013 Critically Endangered B1ac(iv)+2ac(iv)
2012 Critically Endangered B1ac(iv)+2ac(iv)
2011 Critically Endangered B1a+c(iv); B2a+c(iv)
2010 Critically Endangered B1a+c(iv); B2a+c(iv)
2009 Critically Endangered B1a+c(iv); B2a+c(iv)
2008 Critically Endangered
2004 Critically Endangered
2000 Critically Endangered
1996 Endangered
1994 Endangered
1988 Threatened
Species attributes

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

Estimate Data quality
Extent of Occurrence (breeding/resident) 4 km2 medium
Area of Occupancy (breeding/resident) 16 km2 good
Number of locations 1 -
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size 250-999 mature individuals good estimated 2015
Population trend stable good estimated -
Generation length 3.1 years - - -
Number of subpopulations 1 - - -
Percentage of mature individuals in largest subpopulation 100% - - -

Population justification: The population was estimated at 1,558 individuals in November 2011, before it declined to 855 in November 2015 (M. Brooke in litt. 2016). This equates roughly to 570 mature individuals. However, when the population is smaller it can be strongly male-biased, meaning the effective population size is smaller than it first appears (M. Brooke in litt. 2008, 2010, Brooke et al. 2010). Therefore, the population is placed in the band 250-999 mature individuals.

Trend justification: The population undergoes fluctuations due to varying rainfall levels on Raso (Donald et al. 2003, Donald and Brooke 2006, Brooke et al. 2012). It has increased rapidly since 2004, but it is uncertain whether this relates to a temporary fluctuation or a longer-term increase.


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

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Cape Verde Raso Islet Integral Natural Reserve

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Grassland Subtropical/Tropical Dry suitable resident
Marine Intertidal Tidepools marginal resident
Shrubland Subtropical/Tropical Dry major resident
Wetlands (inland) Seasonal/Intermittent/Irregular Rivers/Streams/Creeks major resident
Altitude 0 - 50 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 Whole (>90%) Causing/Could cause fluctuations Medium Impact: 7
Stresses
Ecosystem degradation, Species mortality
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 - Canis familiaris Timing Scope Severity Impact
Future Whole (>90%) Very Rapid Declines Medium Impact: 7
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Felis catus Timing Scope Severity Impact
Future Whole (>90%) Very Rapid Declines Medium Impact: 7
Stresses
Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Named species Timing Scope Severity Impact
Future Whole (>90%) Very Rapid Declines Medium Impact: 7
Stresses
Reduced reproductive success
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Unspecified species Timing Scope Severity Impact
Future Whole (>90%) Unknown Unknown
Stresses
Ecosystem degradation
Invasive and other problematic species, genes & diseases Problematic native species/diseases - Tarentola gigas Timing Scope Severity Impact
Ongoing Whole (>90%) Very Rapid Declines High Impact: 9
Stresses
Reduced reproductive success

Recommended citation
BirdLife International (2024) Species factsheet: Raso Lark Alauda razae. Downloaded from https://datazone.birdlife.org/species/factsheet/raso-lark-alauda-razae on 03/12/2024.
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 03/12/2024.