Re the status of Black-throated Laughingthrush in Guangdong province, records in the past 30 years (mainly HKBWS, KFBG, China Bird Reports, Jonathan Martinez) show that its stronghold is the southwest of the province, where it is common in the hills at 100-1650m (peak day-count 25 in spring) and also occasionally found in the lowlands or on the coast east to Macao.
It is also common in hills near Guangzhou (day-counts of up to 10) and can be found in all seasons in Shenzhen and occasionally a little east of Shenzhen.
Elsewhere in Guangdong, it is much scarcer with one or two reported in hill forests along the West River and in the north and east-central parts at Hei Shi Ding (all seasons), Dinghu Shan, Ba Bao Shan, Dachouding and Nan Kun Shan (mainly spring).
In the past, the populations on the hills of southwest Guangdong (which are presumably of natural occurrence) were unknown and records from Guangzhou and Hong Kong were treated as ex-captive, originating in Guangxi (Nanning and Wuzhou). It's possible that the greening of Guangdong has allowed the species to spread naturally from the southwest or along the West River to reach the Pearl River Delta, but this is not certain.