Justification of Red List category
This species is declining extremely rapidly across its range as a result of trapping of wild birds for the cage-bird trade, compounded by habitat loss within its rather specific habitat type. Therefore, the species is evaluated as Critically Endangered.
A revised population estimate based on an appraisal of the areas where populations are currently persisting, principally large protected areas in Malaysia and the population in Singapore, places the number in the band 1,000-2,499 individuals, considered to represent 667-1,667 mature individuals, rounded to 600-1,700 mature individuals. The Singapore population has recently been estimated to comprise 200-500 mature individuals (Yong et al. 2018, Chiok et al. 2020).
Persecution for the pet trade and habitat destruction continue to threaten populations across the species's range, and these factors are suspected to be driving a rapid and on-going decline that exceeds 80% in the previous three generations (15 years) (Asian Songbird Trade Specialist Group in litt. 2018). Declines have been apparent in parts of the range for several decades (Nash 1993, Wells 2007), with extinction on Java considered to have occurred in the mid-20th Century (van Balen 1999) and in Thailand considered at best close to extinction from a similar time (Wells 2007) (and assumed extinct for some time [Fishpool et al. 2018]). Rates of decline appear to have hit very high levels in the mid-2000s, coinciding with dramatic price rises (Shepherd 2013, Chng et al. 2015, Eaton et al. 2015, Rentschlar et al. 2018), which have continued to the present day, with recent prices quoted at over $700 per bird (Chng et al. 2018). Considered increasingly rare in Kalimantan by the mid-1990s despite being 'so common' two decades previous (Holmes 1997), this decline now appears to have progressed to site level extinctions, e.g. at Bukit Batikap Protection Forest in 2014 (Fischer et al. 2016) and any that remain must be in the most remote areas (Brickle et al. 2010). Any location information appears eagerly sought by trappers and is undoubtedly acted upon (Fischer et al. 2016, A. Miller in litt. 2018, Rentschlar et al. 2018). Numerous inventories of potentially suitable sites undertaken within the species's range over the past decade have failed to find the species, including sites such as Gunung Mulu National Park with records up to 2010 (Burner et al. 2016). Very few are believed to remain in Sumatra, having been considered likely extinct by Eaton et al. (2015), but with recent reports of presence in previously unsurveyed locations (Y. Ding Li in litt. 2018). However, with demand remaining very high, it is predicted that extirpation from Indonesia is imminent. Comparing sites with pre- and post-2000 records, Chiok et al. (2019) identified 10 sites on Borneo, 6 in Peninsular Malaysia and 3 on Sumatra where the species has become extirpated. In Singapore the population is believed to be stable, or possibly increasing slightly (Yong et al. 2018); since this population comprises a large and increasing percentage (likely to be greater than 20%) of the global population, future rates of decline in this species are believed to be slower than previously.
Until the latter part of the 20th century Straw-headed Bulbul was a widespread bulbul of lowland riparian areas from Tenasserim, Myanmar, south through Peninsular Thailand and Malaysia and Singapore to Sumatra, Java and Kalimantan, Indonesia, Brunei and Sabah and Sarawak (Malaysia) (BirdLife International 2001). From being common throughout its large range (southernmost Myanmar and Thailand, Peninsular Malaysia, Sumatra, Java and Borneo) in the 1950s it is now considered with some certainty to be extinct in Thailand and likely Myanmar, Java, Nias and Sipora. It was likely to very close to extinction on Sumatra (Eaton et al. 2015, Chiok et al. 2019). In Kalimantan, it is largely confined to areas furthest from human habitation, where trappers still seemed to obtain individuals into the 2010s (Brickle et al. 2010), but even remote areas now lack the species and it has apparently been lost from all protected lowland areas (A. Miller in litt. 2018, Rentschlar et al. 2018). In Malaysia, the species is now similarly absent from national parks and wildlife sanctuaries in which it was previously common (J. Eaton in litt. 2016, R. Kaur in litt. 2020). In Sabah the species remains present in several locations, but poaching has been reported even in Danum Valley. A population is also still present in Brunei, but numbers are unknown. Of 19 sites where the species was recorded in Borneo pre-2000, recent records indicate it was observed in less than half (47%, Chiok et al. 2019). This is in spite of extensive surveys undertaken at some of these sites (such as Gunung Mulu National Park and Gunung Nyiut Nature Reserve). Comparing pre- and post-2000 Peninsular Malaysia, 14 of 20 sites for which records existed had both historical and contemporary records of the species. Overall, the species is estimated to persist in less than 63% of the sites where it existed pre-2000, though this is likely to be an over-estimate given the rapid decline of the species (Chiok et al. 2019).
The only population that appears to be increasing is found in Singapore, which has been present since at least the 1920s (Y. Ding Li in litt. 2018) and was estimated to contain 202 individuals in 2016 (Yong et al. 2018). Pulau Ubin is considered a stronghold for the species here due to minimal development, although it is thought it may be reaching its carrying cap-acity on the island as expansion of the population inevitably extents into more unsuitable habitats (Keita et al. 2019).
It occupies successional habitats bordering rivers, streams, marshes and other wet areas, where seasonal flooding prevents the establishment of climax communities. These include secondary and disturbed primary evergreen forest, plantations, gardens and cultivation fringe, scrub and, locally, reedbeds and mangroves. It is most frequent in lowlands, but has been recorded (historically) up to 1,100 m and locally (on Borneo and Sumatra) up to 1,600 m. It is sedentary, generally occurring in pairs or family parties of up to five.
The quality of its songs makes it a very popular cage-bird, which has resulted in extensive trapping for both domestic and international trade. Its lack of shyness and habit of roosting and nesting in easily accessible locations has compounded its vulnerability to trapping. A single bird cost around US$20 in 1987 (Basuni and Setiyani 1989), but prices have risen to over 20 times this in 2015 (Bergin et al. 2018). Prices are complicated by the value placed on champion song birds, which compete for very large prizes at events across Java and Bali (Jepson 2008). However an average price for clearly wild-caught untrained birds are alarmingly high: in surveys across west Borneo in 2015/16 it was US$483 (A. Miller in litt. 2016), while in Java a mean of $547 was reported (Chng et al. 2015). But this continues to rise, reinforcing the evidence that scarcity of supply will not reduce demand but rather enhance it. Only three birds were found in an inventory of some bird sellers in Sumatra in 2018, two priced at $752 each and one at $902 (Chng et al. 2018). A 2018 survey of bird ownership involving over 3,000 households in all six of Java’s provinces estimated that 78,738 ± 36,394 individuals are currently kept in Java alone (Marshall et al. 2020).Wild-caught birds are still considered superior and birds without closed rings far outnumbered those that possessed them, indicating a disregard for this form of trade control and a continuing lack of enforcement of illegal trade (S. Chng in litt. 2016, 2018). Bird breeding does not appear to be alleviating demand for wild-caught birds (with prices so high this is no surprise) and some breeding operations in Kalimantan visited were considered to be fronts for trading wild-caught birds (Rentschlar et al. 2018).
Despite its tolerance of secondary habitats, clearance of lowland forest along rivers has probably contributed to its decline and has certainly enabled trappers access to a far greater proportion of the species's range.
Conservation Actions Underway
CITES Appendix II. It is protected in Malaysia and Singapore (Chiok et al 2019). Whilst it is protected in Thailand, but is likely extinct there. Extinctions have also likely occurred in several protected areas on Sumatra, but the species persists in Taman Negara in Peninsular Malaysia at least four in Kalimantan and several (including Taman Negara) in Peninsular Malaysia, though there are very few recent records away from Taman Negara (J. Eaton in litt. 2016). Some are being captive bred at Jurong Bird Park. The species is also captive bred at Wildlife Reserves in Singapore, although the process is not yet deemed sustainable, with protocols being developed to improve breeding knowledge such as hand-rearing of chicks (Keita et al. 2019). A Conservation Planning Workshop was organised in 2019 to head the protection of the species in Singapore, with a conservation strategy developed addressing key areas such as improving monitoring and ecology of the species, improving knowledge of genetics and captive breeding possibilities, implementing advocacy and protection, improving trade and enforcement, and raising community engagement (Keita et al. 2019). Though the species is not listed as a protected species in Indonesia, its harvest and trade is technically illegal (Bergin et al 2018).
29 cm. Large bulbul with golden-yellowish crown and cheeks. Blackish eye and submoustachial stripes, white throat and fine, whitish streaks on upperparts and breast. Juvenile has duller, browner head. Voice Loud, rich, melodious, warbling song. Hints Listen for song in marshes and along forested rivers.
Text account compilers
Murray-Watson, R., Fernando, E., Berryman, A.
Benstead, P., Brickle, N., Chng, S., Ding Li, Y., Eaton, J., Gilroy, J., Jeggo, D., Kaur, R., Mahood, S., Marshall, H., Martin, R., Miller, A., Styring, A., Sulfani Udin, J., Taylor, J., Westrip, J.R.S. & van Balen, B.S.
BirdLife International (2023) Species factsheet: Pycnonotus zeylanicus. Downloaded from http://datazone.birdlife.org/species/factsheet/straw-headed-bulbul-pycnonotus-zeylanicus on 01/12/2023.
Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://datazone.birdlife.org on 01/12/2023.