LC
Cream-vented Bulbul Pycnonotus simplex



Justification

Justification of Red List Category
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

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).

Distribution and population

The species occurs from southeast Myanmar through the Thai-Malay Peninsula and into Sumatra, Java, Borneo and the island groups of Sunda, Anamba, northern Natuna and southern Natuna, Indonesia (Shakya  et al. 2019). The nominate subspecies simplex occurs from southeast Myanmar through the Thai-Malay peninsula with its distribution stretching into Sumatra and Borneo. Subspecies prillwitzi is found throughout the island of Java, while subspecies halizonus occurs throughout the Anamba Islands and northern Natuna Islands (Shakya et al. 2019).

Ecology

This species typically occurs from sea-level up to approximately 1,100 m elevation throughout both mature and disturbed broadleaf evergreen forest (Shakya et al. 2019). It also occurs in forest edges, secondary growth, plantations, peatswamp-forest and heath-forest; it is one of the few bird species regularly found to occur in the extreme Baeckia/Gluta heath-scrub of the Gunung Keriong plateau (Fishpool and Tobias 2019, Shakya et al. 2019). It typically feeds on insects and fruits, including mass produced small fruit or figs, as both individuals and pairs. Whilst several individuals may converge at a fruit source, there is no evidence that it forms larger groups although it regularly joins mixed-species foraging flocks of insectivores (Fishpool and Tobias 2019). The species is usually found in the lower and middle storeys along forest trails, but also ascends to the canopy (Fishpool and Tobias 2019). It breeds between February and October (Fishpool and Tobias 2019).

Threats

The most severe threat stems from deforestation and habitat loss (del Hoyo et al. 2005). Lowland forest has disappeared at a rapid rate in recent decades throughout much of the species's 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 the populations (Fishpool and Tobias 2019). The species also occurs in secondary growth and plantation forests, further reducing the impact of the ongoing deforestation on the population trend (Fishpool and Tobias 2019, Shakya et al. 2019).

Identification

18 cm. A medium-small, nondescript, noisy, conspicuous bulbul. The nominate race's head (except throat) and upperparts are a uniform dark warm olive-brown whilst the upperwings have brighter fringing on secondaries. The tail is dark olive-brown with a slight rufous tinge, darker than the uppertail-coverts; chin and throat whitish with a slight creamy tinge; breast pale brown with cream feather fringing, shading browner at the side and on flanks. The belly to undertail-coverts are a pale creamy white with slight yellow tinge, palest on the tail-coverts, slight greyish-brown wash on breast and flanks. Its iris is strikingly white or yellowish-white, although in Borneo and some Suma­tran satellite islands most have red iris. The bill is black and legs brown. Sexes alike. The juvenile's crown, upperparts and wing-feather fringes are a warmer brown, iris grey-brown, slowly changing to pale orange or warm brown, then pale yellowish to white. The bill is dark brown whilst the feet are brownish-pink. Race P. s. prillwitzi has lighter upperparts and yellower underparts. Race P. s. halizonus is almost identical to nominate but potentially has a fractionally longer and heavier bill.

Acknowledgements

Text account compilers
Everest, J., Ekstrom, J., Butchart, S.


Recommended citation
BirdLife International (2022) Species factsheet: Pycnonotus simplex. Downloaded from http://www.birdlife.org on 24/06/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 24/06/2022.