LC
Costa Rican Warbler Basileuterus melanotis



Taxonomy

Taxonomic note
Basileuterus tristriatusB. melanotisB. tacarcunae and B. punctipectus were previously lumped as B. tristriatus (del Hoyo and Collar 2016) but are split following genetic and vocal analyses that yield congruent results (Donegan 2014, GutiĆ©rrez-Pinto et al. 2012), although plumage divergence is weak, morphometric divergence absent and further work on voice of tacarcunae (known from a single recording) desirable to confirm this rearrangement. Taxon chitrensis is a junior synonym of melanotis (Dickinson and Christidis 2014). Monotypic.

Taxonomic source(s)
Handbook of the Birds of the World and BirdLife International. 2023. Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 8. Available at: https://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v8_Dec23.zip.

IUCN Red List criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - -

Red List history
Year Category Criteria
2023 Least Concern
2016 Not Recognised
2012 Not Recognised
2008 Not Recognised
2004 Not Recognised
2000 Not Recognised
1994 Not Recognised
1988 Not Recognised
Species attributes

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

Estimate Data quality
Extent of Occurrence (breeding/resident) 34,200 km2
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size unknown - - -
Population trend decreasing - suspected 2017-2028
Rate of change over the past 10 years/3 generations (longer of the two periods) 1-9% - - -
Rate of change over the future 10 years/3 generations (longer of the two periods) 1-9% - - -
Rate of change over the past & future 10 years/3 generations (longer of the two periods) 1-9% - - -
Generation length 3.5 years - - -
Number of subpopulations 1 - - -
Percentage of mature individuals in largest subpopulation 100% - - -

Population justification: The population size has not been quantified, but the species is frequently observed across its range (see eBird 2023).

Trend justification: The population trend has not been investigated, but the only threat known to the species is the logging and fragmentation of forests within the range. Tree cover loss within the range is very low (2% over three generations; Global Forest Watch 2023, using Hansen et al. [2013] data and methods disclosed therein). Population declines are therefore likely equally low and localised; they are here tentatively placed in the band 1-9% over three generations.


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

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Montane major resident
Altitude 600 - 2100 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Small-holder farming Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem conversion
Biological resource use Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion

Recommended citation
BirdLife International (2024) Species factsheet: Costa Rican Warbler Basileuterus melanotis. Downloaded from https://datazone.birdlife.org/species/factsheet/costa-rican-warbler-basileuterus-melanotis on 26/12/2024.
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 26/12/2024.