EN
Collared Laughingthrush Trochalopteron yersini



Taxonomy

Taxonomic note

Trochalopteron yersini (del Hoyo and Collar 2016) was previously listed as Garrulax yersini.

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
- B1ab(ii,iv,v) B1ab(ii,iv,v)+2ab(ii,iv,v)

Red List history
Year Category Criteria
2024 Endangered B1ab(ii,iv,v)
2016 Endangered B1ab(i,ii,iii,iv,v)
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 Threatened
Species attributes

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

Estimate Data quality
Area of Occupancy (breeding/resident) 620 km2
Number of locations 3-20 -
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size 2000-10000 mature individuals poor suspected 2023
Population trend decreasing poor inferred -
Generation length 3.62 years - - -
Number of subpopulations 2-10 - - -
Percentage of mature individuals in largest subpopulation 1-89% - - -

Population justification: The population size of this species has not been directly estimated. Robson (2008) and Craik and Lê (2018) both describe it as locally common, corroborating the report of Mahood and Eames (2012) that it is a 'common [species] wherever suitable habitat is found'; the latter authors also found it at 93% (13 of 14) of survey locations where broadleaf evergreen forest was found at a suitable elevation. According to Global Forest Watch (2024) data, approximately 640 km2 of forest lies within its elevational range, although a portion of this is pine forest (which does not host it). Densities for congeners are also unavailable, however it is precautionarily assumed to have a moderately small population comprising 2,000–10,000 mature individuals, but this requires corroboration.

Trend justification: The two principal threats to this species are habitat loss and degradation, and trapping. In the three generations (10.9 years; Bird et al. 2020) to 2023, only c.1% of forest cover was lost in its range (Global Forest Watch 2024, based on data from Hansen et al. [2013] and methods disclosed therein) and some of this may refer to landslides. While this does not include habitat degradation, this too has been minimal (Grantham et al. 2020). Consequently, forest loss and modifications are not thought to be causing declines. Trapping is now thought to comprise a more substantial threat and is known to have removed birds from previously occupied sites (J. Eaton in litt. 2023), as well as having caused the rapid declines in several other laughingthrushes on the Da Lat Plateau, namely Orange-breasted Laughingthrush Garrulax annamensis and White-cheeked Laughingthrush Pterorhinus vassali. Given the pressure on this species, and localised evidence of disappearances, trapping is inferred to be causing declines. However, it remains commonly encountered at some sites, including those easily accessible to hunters, and some parts of its albeit small range are remote and comparatively difficult to access; consequently, declines are not thought to be rapid. Future trends are impossible to predict however, with G. annamensis declining precipitously and somewhat unexpectedly in the last five years because of trapping. The present species' small ranger renders it particularly vulnerable to market whims and changes in demand, and so this should be closely monitored.


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

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Vietnam Bi Dup
Vietnam Chu Yang Sin
Vietnam Cong Troi
Vietnam Lang Bian
Vietnam Phuoc Binh
Vietnam Tuyen Lam

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Montane major resident
Altitude 1500 - 2440 m Occasional altitudinal limits (min) 1400 m

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Majority (50-90%) Unknown Unknown
Stresses
Reduced reproductive success, Species mortality

Utilisation
Purpose Scale
Pets/display animals, horticulture subsistence, national

Recommended citation
BirdLife International (2024) Species factsheet: Collared Laughingthrush Trochalopteron yersini. Downloaded from https://datazone.birdlife.org/species/factsheet/collared-laughingthrush-trochalopteron-yersini 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.