Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.
Critically Endangered | Endangered | Vulnerable |
---|---|---|
- | - | A2c+3c+4c |
Year | Category | Criteria |
---|---|---|
2023 | Vulnerable | A2c+3c+4c |
2016 | Vulnerable | A2c+3c+4c |
2012 | Vulnerable | A2c+3c+4c |
2008 | Vulnerable | A2c; A3c; A4c |
2004 | Vulnerable | |
2000 | Vulnerable | |
1994 | Lower Risk/Near Threatened | |
1988 | Lower Risk/Least Concern |
Migratory status | not a migrant | Forest dependency | medium |
Land-mass type |
shelf island |
Average mass | - |
Estimate | Data quality | |
---|---|---|
Extent of Occurrence (breeding/resident) | 1,600,000 km2 | medium |
Severely fragmented? | no | - |
Estimate | Data quality | Derivation | Year of estimate | |
---|---|---|---|---|
Population size | unknown | poor | - | - |
Population trend | decreasing | poor | suspected | 2016-2027 |
Rate of change over the past 10 years/3 generations (longer of the two periods) | 19-42,30-40% | - | - | - |
Rate of change over the future 10 years/3 generations (longer of the two periods) | 19-42,30-40% | - | - | - |
Rate of change over the past & future 10 years/3 generations (longer of the two periods) | 19-42,30-40% | - | - | - |
Generation length | 3.5 years | - | - | - |
Number of subpopulations | 2-70 | - | - | - |
Percentage of mature individuals in largest subpopulation | 1-89% | - | - | - |
Population justification: The population size of this species has not been quantified, however this species is considered a specialist of stunted forest types (Sheldon 1987), the area of which is difficult to map. Within suitable habitat, it may be regularly observed and can be quite common (Posa and Marques 2012, RER 2017, Eaton et al. 2021, eBird 2022) but the area of available habitat has greatly diminished over the past 20 years, such that the population size, although unquantified here, is likely to be much smaller than three generations ago. On Sumatra, the area of suitable habitat is small and greatly fragmented, with recent records from only a handful of sites on the island's east; here, however, it is always thought to have been rare (see review by van Marle and Voous 1988). On Borneo, the area of habitat is much larger and records (Mann 2008, eBird 2022) suggest it remains widespread.
Trend justification: Setornis criniger is thought to be declining rapidly in response to extensive forest cover loss across its range. In the absence of population data, forest cover loss is used as a proxy to estimate the rate of reduction over the past three generations (10.5 years; Bird et al. 2020), however doing this accurately relies on robust knowledge of the species' distribution when forest cover was more extensive. There is, however, much uncertainty on how widespread it was on Sumatra historically, and its elevational limits on Borneo (where it has on occasion been recorded in kerangas forest up to 1,000 m [Mann 2008]). Under a range of mapped scenarios, forest cover loss in the species' mapped range is thought to have reduced by 19-42% over the last three generations (Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein). Precautionarily, towards the upper limit of these losses (30-40%) is accepted here given the species confinement to specialised habitat. This rate of loss is also suspected to occur into the future, with comparatively little of the species' range circumscribed by protected areas (UNEP-WCMC 2022), and most of it accessible for exploitation.
Country/Territory | Presence | Origin | Resident | Breeding visitor | Non-breeding visitor | Passage migrant |
---|---|---|---|---|---|---|
Brunei | extant | native | yes | |||
Indonesia | extant | native | yes | |||
Malaysia | extant | native | yes |
Country/Territory | IBA Name |
---|---|
Brunei | Belait Swamp Forest |
Brunei | Southern Ladan Hills |
Indonesia | Bukit Baling |
Indonesia | Gunung Palung |
Indonesia | Hutan Rawa Gambut Siak-Kampar |
Indonesia | Kayan Mentarang |
Indonesia | Tanjung Puting |
Indonesia | Tesso Nilo |
Indonesia | Ulu Barito |
Malaysia | Bako-Buntal Bay |
Malaysia | Danum Valley Conservation Area |
Malaysia | Dulit Range |
Malaysia | Klias peninsula |
Malaysia | Lambir Hills National Park |
Malaysia | Lanjak Entimau Wildlife Sanctuary |
Malaysia | Mulu - Buda Protected Area |
Malaysia | Niah National Park |
Malaysia | Sadong-Saribas coast |
Malaysia | Similajau National Park |
Malaysia | Tabin Wildlife Reserve |
Malaysia | Tanjung Datu-Samunsam Protected Area |
Habitat (level 1) | Habitat (level 2) | Importance | Occurrence |
---|---|---|---|
Artificial/Terrestrial | Plantations | suitable | resident |
Forest | Subtropical/Tropical Moist Lowland | suitable | resident |
Forest | Subtropical/Tropical Swamp | major | resident |
Altitude | 0 - 1000 m | Occasional altitudinal limits |
Threat (level 1) | Threat (level 2) | Impact and Stresses | |||||||
---|---|---|---|---|---|---|---|---|---|
Agriculture & aquaculture | Annual & perennial non-timber crops - Agro-industry farming | Timing | Scope | Severity | Impact | ||||
Ongoing | Majority (50-90%) | Rapid Declines | Medium Impact: 7 | ||||||
|
|||||||||
Agriculture & aquaculture | Annual & perennial non-timber crops - Shifting agriculture | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
|||||||||
Agriculture & aquaculture | Annual & perennial non-timber crops - Small-holder farming | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
|||||||||
Agriculture & aquaculture | Wood & pulp plantations - Agro-industry plantations | Timing | Scope | Severity | Impact | ||||
Ongoing | Majority (50-90%) | Rapid Declines | Medium Impact: 7 | ||||||
|
|||||||||
Biological resource use | Logging & wood harvesting - Unintentional effects: (large scale) [harvest] | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
|||||||||
Biological resource use | Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
|||||||||
Natural system modifications | Fire & fire suppression - Trend Unknown/Unrecorded | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
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Residential & commercial development | Commercial & industrial areas | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
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Residential & commercial development | Housing & urban areas | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
Recommended citation
BirdLife International (2024) Species factsheet: Hook-billed Bulbul Setornis criniger. Downloaded from
https://datazone.birdlife.org/species/factsheet/hook-billed-bulbul-setornis-criniger on 23/12/2024.
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 23/12/2024.