Cream-vented Bulbul Pycnonotus simplex


Taxonomic note
Pycnonotus simplex has been split into Cream-vented Bulbul P. simplex and Cream-eyed Bulbul P. pseudosimplex after Shakya et al. (2019) discovered that white-eyed birds on Borneo hitherto considered variants of red-eyed P. simplex are genetically distinct and more closely related to Ashy-fronted Bulbul P. cinereifrons of Palawan, while Bornean P. simplex are sister to white-eyed P. simplex of the Thai-Malay Peninsula. Since they are sympatric with red-eyed birds, white-eyed Bornean birds must constitute a species, P. pseudosimplex.

Apart from the molecular difference the new form differs by its iris colour (score 3), ‘in being yellower on the throat and vent, creating greater contrast with the darker breast and flanks’ (1), and in seemingly small morphometric characters, with a shorter, shallower bill—when data on males (the paper does not discriminate by sex) are compared, P. pseudosimplex has a mean bill depth of 4.06 SD 0.31 (n=7) vs 4.66 SD 0.23 (n=5) resulting in an effect size of ₋2.21 (score 2).

Taxonomic source(s)
Shakya, S. B., Lim, H. C., Moyle, R. G., Rahman, M. A., Lakim, M., & Sheldon, F. H. 2019. A cryptic new species of bulbul from Borneo. Bulletin of the British Ornithologists’ Club 139(1): 46-55.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - -

Red List history
Year Category Criteria
2019 Least Concern
Species attributes

Migratory status not a migrant Forest dependency Medium
Land mass type Average mass 25 g

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 4,040,000
Number of locations -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals unknown not applicable not applicable 0
Population trend Decreasing suspected -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) - - -
Decline (10 years/3 generation past and future) - - -
Number of subpopulations - - -
Percentage in largest subpopulation - - -

Population justification: The global population size has not been quantified, but the species is described as fairly common or very common across much of its range (Fishpool and Tobias 2019).

Trend justification: While the population trend has not been assessed directly, the population is thought to be in decline as a result of rapid ongoing deforestation and habitat loss (del Hoyo et al. 2005). Lowland forest has disappeared at a rapid rate in recent decades throughout much of its range, including Sumatra, Java and Borneo (Hansen et al. 2013, Fishpool and Tobias 2019, Global Forest Watch 2019). This species is particularly at risk as a result of its strong reliance on well-developed forest habitats, although its use of foothill and submontane heath-like habitats help to offset the decreasing trend suspected in P. simplex populations (Fishpool and Tobias 2019).

Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Brunei N Extant Yes
Indonesia N Extant Yes
Malaysia N Extant Yes
Myanmar N Extant Yes
Singapore N Extant Yes
Thailand N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Thailand Khao Nor Chuchi
Thailand Khao Banthad
Thailand Thaleban
Thailand Hala Sector, Hala-Bala Wildlife Sanctuary and Bang Lang National Park
Thailand Bala Sector, Hala-Bala Wildlife Sanctuary
Thailand Chaloem Pra Kiet (Pa Phru to Daeng)
Malaysia Bako-Buntal Bay
Malaysia Trus Madi Range
Malaysia Belum-Temenggor
Malaysia Bintang Range
Malaysia Endau-Rompin
Malaysia Selangor Heritage Park
Malaysia Kabili-Sepilok
Malaysia Mount Kinabalu
Malaysia Kledang Range
Malaysia Krau Wildlife Reserve
Malaysia Kinabatangan floodplain
Malaysia Maliau Basin Conservation Area
Malaysia Nakawan Range
Malaysia Panti forest
Malaysia Pondok Tanjung Forest Reserve
Malaysia South-east Pahang peat swamp forest
Malaysia Tabin Wildlife Reserve
Malaysia Taman Negara National Park
Malaysia Tanjung Tuan
Malaysia Ulu Muda
Malaysia Tanjung Datu-Samunsam Protected Area
Malaysia Gunung Pueh
Malaysia Gunung Penrissen
Malaysia Sadong-Saribas coast
Malaysia Kelabit Highlands
Malaysia Central Titiwangsa Range

Habitats & altitude
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  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Biological resource use Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Ecosystem degradation, Ecosystem conversion

Purpose Primary form used Life stage used Source Scale Level Timing
Pets/display animals, horticulture - - International Non-trivial Recent

Recommended citation
BirdLife International (2022) Species factsheet: Pycnonotus simplex. Downloaded from on 29/11/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from on 29/11/2022.