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

Justification of Red List category
This species has a very small and restricted population and range, has only one subpopulation and is likely to be declining as a result of deforestation. For these reasons the species is evaluated as Critically Endangered.

Population justification
The population has been estimated to number 50-230 individuals (Riley 2002, Collar et al. 2013, R. Martin in litt. 2016), equating to 33-153 mature individuals, rounded here to 30-150 mature individuals.

Trend justification
Small scale clearance at the edges of remaining forest continues, and clearings have also been created and maintained on the ridge in a few places for using mist nets to catch bats for food (R. Martin in litt. 2016). Therefore, the population is likely in decline.

Thapsinillas platenae is found only on Sangihe Island, Indonesia, where there are potentially only 50-230 individuals remaining at one site (the Sahendaruman crater) (Riley 2002, Collar et al. 2013, R. Martin in litt. 2016), where the modelled extent of suitable habitat is only 10.5 km² (Martin 2018). Most of Sangihe has been deforested and converted to agriculture and this species is virtually absent from plantations and secondary growth, suggesting an intolerance for habitat degradation (Fishpool et al. 2016). Small scale clearance at the edges of remaining forest continues, and clearings have also been created and maintained on the ridge in a few places for using mist nets to catch bats for food (R. Martin in litt. 2016). Therefore, the population is likely in decline.

Occurs from the ridgeline (maximum elevation 1,040 m) down to about 650m above sea level in the primary montane type forest that remains around the Sahendaruman crater (Martin 2018). One previous record was from secondary forest adjacent to primary forest, but appears unable to persist in secondary forest, mixed tree agriculture or plantations (unlike other members of the 'golden bulbul' complex [Collar et al. 2013, Fishpool et al. 2016]). This species is found in small groups, possibly representing family groups or ‘breeding units’ (R. Martin in litt. 2016). It appears to have similar requirements to Sangihe Whistler Coracornis sanghirensis but is predicted to have a slightly larger area of suitable habitat remaining (still only 11.5 km² [Martin 2018]). However, it is also suspected to require a larger resident territory on the basis of the loud and far-carrying song (R. Martin pers. obs.).

Most of Sangihe has been deforested and converted to agriculture and this species is virtually absent from plantations and secondary growth, suggesting an intolerance for habitat degradation (Fishpool et al. 2016). Small scale clearance at the edges of remaining forest continues, and clearings have also been created and maintained on the ridge in a few places for using mist nets to catch bats for food (R. Martin in litt. 2016).

Conservation Actions Underway
The Gunung Sahendaruman Protection Forest encloses an area of 3,500 hectares, but forest of good condition is only found within an area of 1,300 hectares (Martin 2018). Within this, only a proportion is suitable for the species (Martin 2018). The Protection Forest is largely mixed agriculture and spice tree plantations, which does not satisfy the designated role of the area to maintain environmental services (water, land stability). Some forest is additionally protected as watershed for a hydroelectric scheme in the Kentuhang valley, though this is within the Protection Forest boundary. Since 2014, the day to day management of the Protection Forest is under the jurisdiction of the provincial government, and a Forest Management Unit was established in 2017 to undertake this duty.

Burung Indonesia have been conducting periodic monitoring of the Critically Endangered species around the Sahendaruman crater with support from Vogelbescherming (Burung Indonesia 2009, Fauzan and Bashari 2016).

An MPhil. project conducted fieldwork on Sangihe in 2015 (Martin 2018) investigated habitat associations of the critically endangered species to model the current extent of suitable habitat and evaluate the potential for habitat restoration in different locations on the island. Burung Indonesia developed a series of community-based Village Resource Management Agreements (VRMAs) at key villages around the crater during the Global Environment Fund-supported conservation project between 2002 and 2006, which successfully slowed rates of forest clearance (BirdLife Indonesia 2007). Between 1995 and 2005 the 'Action Sampiri' project worked for biodiversity conservation in Sangihe and Talaud, conducting fieldwork, establishing conservation awareness programmes (including village and school meetings, distribution of leaflets etc.) and developing ideas for future land-use through agreements between interested parties (local people, local government, forestry officials and timber companies). Sangihe is a priority site for the Critical Ecosystem Partnership Fund, and Burung Indonesia are the Regional Implementation Team for the Wallacea Hotspot. A project conducting a forest cover survey through ground-truthing remote sensed forest cover maps began in 2017, and an extension of the VRMA programme is planned.

There have been proposals to change the designation of the Protection Forest around the Sahendaruman crater to the more strictly controlled wildlife reserve; however, this is considered to have the potential to greatly deteriorate community attitudes to the site, with potentially severely damaging results (Fauzen and Bashari 2016). The Wildlife Conservation Society has also worked on the island since 2007, trying to promote sympathetic land use and development by villages surrounding the crater (N. Brickle in litt. 2010). A local resident and former bird guide is monitoring the loss of native forest for plantations of exotic tree species and trying to raise awareness of the threat this poses to the species (Sykes 2009, W. Pangimangan in litt. 2015).

Conservation Actions Proposed
Ensure effective protection of habitat on Gunung Sahendaruman and work with local communities to restore recently degraded habitat within valleys otherwise suitable for the species. Support work to zone the remaining habitat within the Protection Forest boundary, and define a core forest area with collaboration with those that extract resources from the forest. Continue education programmes emphasising the value of forest cover to water retention and the benefits of sound farming practices on already cleared slopes. Lobby against government initiatives that encourage the clearance of native forest for plantations of exotic tree species. Update information on forest cover and conversion rates.

Text account compilers
Ekstrom, J., Wheatley, H., Butchart, S., Martin, R.

Contributors
Martin, R.

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Recommended citation
BirdLife International (2024) Species factsheet: Sangihe Golden Bulbul Hypsipetes platenae. Downloaded from https://datazone.birdlife.org/species/factsheet/sangihe-golden-bulbul-hypsipetes-platenae on 27/11/2024.
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 27/11/2024.