VU
Cocos Flycatcher Nesotriccus ridgwayi



Taxonomy

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.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - D2

Red List history
Year Category Criteria
2020 Vulnerable D2
2016 Vulnerable D2
2012 Vulnerable D2
2008 Vulnerable D2
2006 Vulnerable
2004 Vulnerable
2000 Vulnerable
1996 Vulnerable
1994 Vulnerable
1988 Lower Risk/Least Concern
Species attributes

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

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 30 medium
Number of locations 1 -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 6000-15000 poor suspected 2000
Population trend Stable poor suspected -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) - - -
Decline (10 years/3 generation past and future) - - -
Number of subpopulations 1 - - -
Percentage in largest subpopulation 100 - - -

Population justification: The population has been estimated at several tens of thousands of individuals (del Hoyo et al. 2004), but has conservatively been placed in the range band for 10,000-19,999 individuals. This equates to 6,667-13,333 mature individuals, rounded here to 6,000-15,000 mature individuals.

Trend justification: Introduced herbivores are degrading habitat within the species's range, but it appears to tolerate some habitat modification and there is (as yet) no evidence of a decline in its range or population. It is therefore suspected to be stable.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Costa Rica N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Costa Rica Cocos Island

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Lowland major resident
Forest Subtropical/Tropical Swamp suitable resident
Shrubland Subtropical/Tropical Moist suitable resident
Wetlands (inland) Shrub Dominated Wetlands suitable resident
Altitude 0 - 570 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Human intrusions & disturbance Recreational activities Timing Scope Severity Impact
Ongoing Minority (<50%) No decline Low Impact: 4
Stresses
Species disturbance
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Capra hircus Timing Scope Severity Impact
Ongoing Minority (<50%) No decline Low Impact: 4
Stresses
Ecosystem degradation
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Felis catus Timing Scope Severity Impact
Ongoing Minority (<50%) No decline Low Impact: 4
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Named species Timing Scope Severity Impact
Ongoing Minority (<50%) No decline Low Impact: 4
Stresses
Reduced reproductive success
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Odocoileus virginianus Timing Scope Severity Impact
Ongoing Minority (<50%) No decline Low Impact: 4
Stresses
Ecosystem degradation
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Sus domesticus Timing Scope Severity Impact
Ongoing Minority (<50%) No decline Low Impact: 4
Stresses
Ecosystem degradation

Recommended citation
BirdLife International (2022) Species factsheet: Nesotriccus ridgwayi. Downloaded from http://www.birdlife.org on 03/07/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 03/07/2022.