Justification of Red List Category
This species has declined very rapidly in the recent past as a result of unsustainable trapping for the domestic cage bird trade in Indonesia, leaving the species with a tiny and restricted population that is considered to be at high risk of imminent extinction in the wild. For these reasons, it is listed as Critically Endangered.
There are potentially two populations, though there are only two recent records of wild individuals on one island and the situation there may be complicated by possible releases that may have taken place. Any wild population on this island numbers fewer than 50 mature individuals. The species has recently been found to still occur at one other island, where the species is currently well-protected and estimated at at least 250 individuals (F. Rheindt in litt. 2020). Overall the population is estimated at between 250-400 individuals, roughly equivalent to 160-270 mature individuals. Concern over poaching from this island is very high, although rangers have been in place supported by a regional NGO to reduce the risk (F. Rheindt in litt. 2020). However on another island within the former range, the species is apparently now extinct, having disappeared following a period of intense trapping on the island, which principally targeted White-rumped Shama (Eaton et al. 2016).
This species is seriously impacted by capture for the domestic cage bird trade. On one island it was reported to have become extinct within a very short period of time after 'hundreds' of trappers came to the island targeting White-rumped Shama Kittacinlca malabarica at some time in 2010 (Eaton et al. 2015). As such, the species is considered to be undergoing an extremely rapid decline. Further reports of confiscations of apparently wild-caught individuals (KSDAE 2018) indicate that this is likely to be continuing.
This species occurs only on islands off the coast of Sumatra, Indonesia.
This species occurs in moist evergreen forest, previously throughout the islands to which it is restricted. It is known for its ability to mimic noises including human speech.
Gracula robusta is highly desired as a songbird, perhaps even more so than the other Hill Mynas due to its large size and loud voice (Shepherd et al. 2006, Harris et al. 2015). Trade has seriously impacted this species, with significant population declines noted in recent years following the targeting of the form for the domestic cage bird trade. It has been reported to have become extinct within a very short time period on one island following the arrival of 'hundreds' of trappers sometime in 2010 (Eaton et al. 2015), from previously having a small but apparently stable population there. The current population in the wild is tiny, and occurs on only two islands, and on one it appears to be solely supported by a project directly overseeing the final few birds and undertaking captive breeding. The threat of the capture of the entire remaining wild population is very real.
The potential for deliberate hybridisation of Gracula religiosa with this species to increase the value of the offspring is very high; should these birds be included in releases, genetic introgression throughout the tiny remaining population may occur.
Conservation Actions Underway
Gracula robusta is an officially protected species in Indonesia (Ministry of Environment and Forestry (Indonesia) 2018) under MoEF RI Regulations (P.106/MENLHK/SETJEN/KUM.1/12/2018). As a result of concerns about international trade, Hill Myna was included in CITES Appendix III at the request of Thailand in 1992 and subsequently included in Appendix II in 1997 on the recommendation of the Netherlands and the Philippines: at present G. robusta remains included within G. religiosa for the Appendix II listing. Considerable efforts are being made on the ground by an Indonesian NGO to establish a recovery programme for the species on one island, coordinated from Sumatra. There is also an attempt to create a captive, integral population of this species, though the present state of the programme is unclear.
Conservation Action Proposed
Strengthen the control, monitoring and law enforcement of trade. All trade in Hill Myna's must be through the appropriate documented legal routes, and trade in G. robusta should be entirely restricted. A detailed program including considerable benefits to local communities must be developed and implemented, with the species 'Beo' as a source of regional pride and identity. Institutions should take steps to ensure that captive holdings are correctly identified, genetically, and conservation breeding should proceed with the intention of maintaining the integrity of the wild forms.
By some way the largest of the Hill Mynas, bulkier and considerably heavier than any other form and with a much a much larger white wing flash. It is perhaps most notably and sadly distinguished by the reputation for having the greatest voice out of this vocally-adept group; described as having a greater repertoire, clarity of tone and force of delivery.
Text account compilers
Rheindt, F., Eaton, J., Westrip, J.R.S. & Symes, A.
BirdLife International (2021) Species factsheet: Gracula robusta. Downloaded from http://www.birdlife.org on 24/10/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 24/10/2021.