VU
Clarion Wren Troglodytes tanneri



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
- - D1+2

Red List history
Year Category Criteria
2020 Vulnerable D1+2
2016 Vulnerable D1+2
2012 Vulnerable D1+2
2008 Vulnerable D1; D2
2004 Vulnerable
2000 Vulnerable
1996 Vulnerable
1994 Vulnerable
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) 38 km2 medium
Number of locations 1 -
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size 340-400 mature individuals medium estimated 2000
Population trend stable poor suspected 1998-2008
Generation length 2.44 years - - -
Number of subpopulations 1 - - -
Percentage of mature individuals in largest subpopulation 100% - - -

Population justification: The population is estimated to number 170-200 pairs, or 340-400 mature individuals and the species is apparently common throughout all of the island and around the naval garrison. According to recent data (Ortiz-Alcaraz et al. 2018), density estimates are 3.2 individuals/ha in the wet season and 6.55 individuals/ha in the dry season. Further population studies are needed.

Trend justification: There are recent counts but no new data on population trends. The introduced mammal that remains on Clarión is the European Rabbit and no evidence of negative impacts exists, aside from greatly slowing vegetation regrowth after a significant fire in the 1980s. Therefore, the population is currently suspected to be stable, although this warrants further investigation.


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

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

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Artificial/Terrestrial Rural Gardens suitable resident
Shrubland Subtropical/Tropical Dry major resident
Altitude 0 - 335 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Climate change & severe weather Habitat shifting & alteration Timing Scope Severity Impact
Future Whole (>90%) Unknown Unknown
Stresses
Indirect ecosystem effects, Ecosystem degradation
Climate change & severe weather Storms & flooding Timing Scope Severity Impact
Ongoing Whole (>90%) Rapid Declines High Impact: 8
Stresses
Indirect ecosystem effects, Ecosystem degradation
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
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 - 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 - Oryctolagus cuniculus Timing Scope Severity Impact
Ongoing Whole (>90%) Negligible declines Medium Impact: 6
Stresses
Ecosystem degradation
Invasive and other problematic species, genes & diseases Problematic native species/diseases - Athene cunicularia Timing Scope Severity Impact
Ongoing Unknown Unknown Unknown
Stresses
Reduced reproductive success
Invasive and other problematic species, genes & diseases Problematic native species/diseases - Named species Timing Scope Severity Impact
Ongoing Unknown Unknown Unknown
Stresses
Reduced reproductive success
Natural system modifications Fire & fire suppression - Trend Unknown/Unrecorded Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
Stresses
Ecosystem degradation, Species mortality

Recommended citation
BirdLife International (2024) Species factsheet: Troglodytes tanneri. Downloaded from https://datazone.birdlife.org/species/factsheet/clarion-wren-troglodytes-tanneri on 24/02/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org on 24/02/2024.