Data Zone
Taxonomic note
Iole charlottae (del Hoyo and Collar 2016) was previously listed as I. olivacea.
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 |
|---|---|---|
| - | - | - |
| Year | Category | Criteria |
|---|---|---|
| 2024 | Near Threatened | A2c+3c+4c |
| 2016 | Near Threatened | A2c+3c+4c |
| 2012 | Near Threatened | A2c+3c+4c |
| 2008 | Near Threatened | A2c; A3c; A4c |
| 2004 | Near Threatened | |
| 2000 | Lower Risk/Near Threatened | |
| 1994 | Lower Risk/Least Concern | |
| 1988 | Lower Risk/Least Concern |
| Migratory status | not a migrant | Forest dependency | high |
| Land-mass type |
continent shelf island |
Average mass | - |
| Estimate | Data quality | |
|---|---|---|
| Extent of Occurrence (breeding/resident) | 4,090,000 km2 | medium |
| Severely fragmented? | no | - |
| Estimate | Data quality | Derivation | Year of estimate | |
|---|---|---|---|---|
| Population size | unknown | - | - | - |
| Population trend | decreasing | poor | inferred | 2016-2026 |
| Rate of change over the past 10 years/3 generations (longer of the two periods) | 15-25% | - | - | - |
| Rate of change over the future 10 years/3 generations (longer of the two periods) | 15-25% | - | - | - |
| Rate of change over the past & future 10 years/3 generations (longer of the two periods) | 15-25% | - | - | - |
| Generation length | 3.25 years | - | - | - |
| Number of subpopulations | 3-50 | - | - | - |
| Percentage of mature individuals in largest subpopulation | 1-89% | - | - | - |
Population justification: The global population size of this species has not been quantified, but it is relatively common (Wells 2007, Eaton et al. 2021, eBird 2024) in remaining tracts of lowland forest, which remain widespread, although much reduced in extent compared to three generations ago. Accordingly, its global population size is likely to be relatively large.
Trend justification: No direct population trend data are available for this species, however remote sensing data are considered a suitable proxy for this forest-dependent species. Over the past ten years, forest cover within its range was reduced by c. 14-18% (Global Forest Watch [2024], based on data from Hansen et al. [2013] and methods therein). This species is commonest at lower elevations, where rates have been most rapid, and the species may be additionally impacted by forest degradation and fragmentation. Accordingly, rates of population reduction may be slightly higher than remote sensing data alone indicate; the rate of population reduction for the past three generations is set at 15-25%.
| Country/Territory | Presence | Origin | Resident | Breeding visitor | Non-breeding visitor | Passage migrant |
|---|---|---|---|---|---|---|
| Brunei | extant | native | yes | |||
| Indonesia | extant | native | yes | |||
| Malaysia | extant | native | yes | |||
| Myanmar | extant | native | yes | |||
| Singapore | extinct | native | yes | |||
| Thailand | extant | native | yes |
| Habitat (level 1) | Habitat (level 2) | Importance | Occurrence |
|---|---|---|---|
| Artificial/Terrestrial | Plantations | suitable | resident |
| Artificial/Terrestrial | Subtropical/Tropical Heavily Degraded Former Forest | suitable | resident |
| Forest | Subtropical/Tropical Moist Lowland | major | resident |
| Forest | Subtropical/Tropical Moist Montane | suitable | resident |
| Forest | Subtropical/Tropical Swamp | suitable | resident |
| Altitude | 0 - 1100 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 | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
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| 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 | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
|||||||||
| 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%) | Negligible declines | Low Impact: 4 | ||||||
|
|||||||||
| Natural system modifications | Fire & fire suppression - Increase in fire frequency/intensity | Timing | Scope | Severity | Impact | ||||
| Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
|||||||||
| Purpose | Scale |
|---|---|
| Pets/display animals, horticulture | subsistence, national, international |
Recommended citation
BirdLife International (2024) Species factsheet: Buff-vented Bulbul Iole charlottae. Downloaded from
https://datazone.birdlife.org/species/factsheet/buff-vented-bulbul-iole-charlottae 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.