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

This Vietnamese endemic is listed as Endangered because it has a very small range on the Da Lat Plateau, within which it is at high risk from the threat of trapping, which has caused catastrophic regional declines in other laughingthrush species. It probably also has a small population size (<10,000 mature individuals). 

Trochalopteron yersini is endemic to the Da Lat plateau, Viet Nam (Mahood and Eames 2012).

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.

It is resident in dense undergrowth of primary and logged montane evergreen forest, secondary growth and scrub bordering forest, occupying a narrow altitudinal band from 1,500–2,440 m, although it has been recorded below 1,450 m (Mahood and Eames 2012). It is generally encountered in monospecific flocks of 4–8 individuals. Juveniles have been collected between April–June, suggesting the main breeding season is probably from March-May.

A government resettlement programme has greatly increased human pressure on the Da Lat Plateau. While concern in response to this was previously directed about putative accelerations in forest loss, degradation and fragmentation, these have so far failed to materialise, with much of this species' range remaining unmodified (Global Forest Watch 2024). By far the most impactful threat, which has insidiously increased in acuity and extent over the past two decades, is that of trapping to fuel Viet Nam's songbird trade. The scale and extent to which this poses an extinction risk to this species is not well understood, but there is evidence of other laughingthrushes being heavily trapped in and around Da Lat, and this species has disappeared from sites it once occupied. Given its relatively small range, not much of this species' habitat can be considered wholly secure from trapping.

Trapping for the songbird trade is now considered the principal threat to this species. It occupies only a small area of habitat probably <500 km², from which only small areas could reasonably be considered remote from trapping. There is an increasing body of evidence from Viet Nam that laughingthrushes are widely traded (e.g. Eaton et al. 2017, Leupen et al. 2022) as is true of elsewhere in South-East Asia and more specifically in Da Lat (where, for example, sympatric populations of White-cheeked Laughingthrush P. vassali now occur in much smaller flocks than they once did: J. Eaton pers. comm.) and Orange-breasted Laughingthrush Garrulax annamensis, also endemic to the Da Lat Plateau, is also considered to be of conservation concern.

Conservation Actions Underway
Part of its range is protected (e.g. Bi Doup Nui Ba National Park) but the extent to which this status buffers T. yersini from trapping pressure is unknown.

Conservation Actions Proposed
Conduct surveys to clarify its habitat requirements, population size and local distribution. Conduct detailed market surveys around Da Lat to more objectively evaluate the extent to which trapping is threat to this species. Ensure that protected areas in this species' range do confer adequate protection from trappers.