Data Zone
Justification of Red List category
The species has suffered a very rapid, ongoing population decline due to trapping for trade compounded by habitat loss. Local extinctions had been observed across much of the range within the past 10-15 years concurrent with price increases and reduced availability in the market. Recent information further suggests trade and harvest has continued at a rapid scale. For these reasons Sumatran Laughingthrush is evaluated as Endangered.
Population justification
The species was reportedly common and widespread in 1988 but is now known few sites throughout the range where only very small numbers have been located in the wild recently. More than 45 km of transects in suitable habitat in 2013 returned only a single record of the species (Eaton et al. 2015). Trappers in West Sumatra stated in 2015 that it remained in forests three days walk from a road (Eaton et al. 2015). In 2017, surveys also failed to detect the species at several sites across Northern Sumatra (c.156 transects across Karo, Deli Serdang, Langkat, and Dairi regencies) (Harris et al. 2017). The largest extent of remaining habitat is in Aceh province, where the species is still relatively widespread though highly localised and heavily trapped (Eaton et al. 2015). Bird tours to this area have located groups by the roadside, indicating that trapping pressure is lower in this culturally separate region of Sumatra (Eaton 2014). The paucity of records from the majority of the range indicates that the species now has a small population size. It is here tentatively placed in the band 2,500-9,999 mature individuals. This equates to 3,750-14,999 individuals, rounded here to 3,500-15,000 individuals.
Trend justification
Numbers in trade had been falling coincident with a rapid increase in the price per bird from $8-15 in 2007 to $90 in 2014 (Chng et al. 2014; Harris et al. 2015), coupled with an expert review of the status of the bird in the wild concluding that it was 'Severely Declining' (Harris et al. 2015). Recent surveys and different methodologies however reveal that numbers in markets have continued to be high, highlighting the ongoing, unsustainable level of harvest (Bušina et al. 2018a). In the wild the species has therefore disappeared from several sites where it was being regularly recorded only a decade ago.
Garrulax bicolor was originally distributed along the length of the montane spine of Sumatra, Indonesia, from Aceh in the north to Lampung in the south (van Marle and Voous 1988), and was reportedly common. Recent evidence suggests that it has undergone a very considerable decline and become rare and locally extinct at several locations where it present less than a decade ago (Eaton et al. 2015). It was present at a small number of sites scattered across Sumatra, including Bukit Barisan Selantan National Park (no recent records here however; Shepherd et al. 2016), Danau Ranau (South Sumatra) (R. Thomas per C. R. Shepherd in litt. 2012), Batang Toru (North Sumatra) and Ulu Masen (Aceh) (N. Brickle in litt. 2007), and a single locality in Kerinci Seblat National Park (S. Högberg in litt. 2006). However, since 2012 there have been few records away from Aceh province. A small group of three birds was camera trapped in Batang Toru (G. Fredriksson per C. R. Shepherd in litt. 2012).
This species is known from broadleaf, evergreen montane forests (with unsubstantiated reports of a lowland population in Berbak Game Reserve, Jambi). It lives in flocks in the middle and lower storeys of forest sometimes coming to the ground. The species may also occur in secondary forests, as observed at forests near the east of Lake Toba, Sumatra, Indonesia (T. Wheatley in litt. 2015).
The principal threat to this species is the illegal trade for the cage bird industry at a national level (Shepherd 2006, 2007, 2011; Eaton et al. 2015; Harris et al. 2015). As there are no commercial breeding programmes of the species, all traded individuals are considered to be wild-caught (Shepherd and Gomez 2018). The vast majority of trade is also illegal and unregulated (Shepherd 2007, 2011). Prior to 2005 the widespread sister species G. leucolophus was preferentially traded but international imports of wild birds were stopped in that year due the avian flu risk (Owen et al. 2014), which was suggested to have driven a sudden surge of domestic bird trapping within Indonesia, with G. bicolor being the ready replacement at hand in Sumatra (Owen et al. 2014; Shepherd et al. 2016). However, it is more likely that the species became more common among trade markets following continued import restrictions on G. leucolophus (Shepherd and Gomez 2018). Numbers observed in markets increased and 20-30 were regularly seen between 2008-2013, but in 2016 only 5 birds were observed and prices had increased to two birds for ca US$100 (A. Owen in litt. 2016). During 2015-2016 however, c. 2,610 wild-caught individuals were found to have been traded across six prominent vendors in Medan's Jalan Bintang market, with market mortality up to 16% (Bušina et al. 2018a). Whilst this was likely due to differences in monitoring and collection methods in comparison to previous years, the volume of trade reveals that harvesting continues to be unsustainable. It may also have declined owing to deforestation within its range, though perhaps principally through increasing the percentage of the species range that is accessible for trapping.
Conservation Actions Underway
In 2018, the species was granted legal protection by the Indonesian Government (Shepherd and Gomez 2018). The harvest of the species is now strictly prohibited with violation of regulations incurring a five-year prison sentence or fines of IDR 100 million (US$7,000). Captive breeding of this species has also been successful on a small scale in the UK, however, only two attempts have been undertaken at establishing an ex-situ captive breeding population in Java and Sumatra, Indonesia (C. R. Shepherd in litt. 2012; Owen et al. 2014; Bušina et al. 2018b). These include a captive breeding programme in the Cikananga Wildlife Centre on Java Island and the Indonesian Species Conservation Programme (ISCP) on Sumatra Island attempting to use wild-caught birds from households for reintroduction (Bušina et al. 2018b). An independent reintroduction programme was recently carried out in Northern Sumatra using wild-caught rehabilitated birds, also highlighting important issues in post-release behaviour (Bušina et al. 2018b). The species is present in Gunung Leuser and Kerinici Seblat National Parks (Collar et al. 2020).
30 cm. Brownish-black with unmistakeable white head with slightly erectile crest extending to the breast, distinctive triangular black forehead, lores and drooping eye-stripe. Similar spp body colour of bicolor is darker than continental forms of White-crested Laughingthrush Garrulax leucolophus, lacking the rufous or mouse-brown tones shown in that species.
Text account compilers
Martin, R., Fernando, E.
Contributors
Allinson, T, Bird, J., Brickle, N., Butchart, S., Chng, S., Eaton, J., Gilroy, J., Hogberg, S., Owen, A., Shepherd, C., Taylor, J. & Wheatley, T.
Recommended citation
BirdLife International (2024) Species factsheet: Sumatran Laughingthrush Garrulax bicolor. Downloaded from
https://datazone.birdlife.org/species/factsheet/sumatran-laughingthrush-garrulax-bicolor on 05/12/2024.
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 05/12/2024.