• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

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.

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

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

	Estimate	Data quality
Area of Occupancy (breeding/resident)	620 km2
Number of locations	3-20	-
Severely fragmented?	no	-

	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	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Vietnam	extant	native	yes

Country/Territory	IBA Name
Vietnam	Bi Dup
Vietnam	Chu Yang Sin
Vietnam	Cong Troi
Vietnam	Lang Bian
Vietnam	Phuoc Binh
Vietnam	Tuyen Lam

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

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

Purpose	Scale
Pets/display animals, horticulture	subsistence, national

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Recommended citation
BirdLife International (2024) Species factsheet: Collared Laughingthrush Trochalopteron yersini. Downloaded from https://datazone.birdlife.org/species/factsheet/collared-laughingthrush-trochalopteron-yersini on 23/11/2024.
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 23/11/2024.