Data Zone
Justification of Red List category
This forest-associated species is listed as Near Threatened because it is suspected to be undergoing a moderately rapid decline (20-29% over three generations) owing to the extensive loss of lowland forests from large areas of the Sundaic lowlands.
Population justification
The global population size of this species has not been quantified, but it is relatively common (Eaton et al. 2021, eBird 2024) in remaining tracts of swampy lowland forest, which remain widespread, although much reduced in extent compared to three generations ago. Using genetic data, Cros et al. (2020) estimated the effective population size (Ne) of 175,500 (95% CI 167,800-207,400) in 'Western Sundaland' and 312,700 (297,200-354,800) on Borneo, thus a combined total of c.488,000 (465,000-562,000). The number of mature individuals is typically greater than that of Ne, and so the global population size is thought to number in the hundreds of thousands, if not low millions. It is therefore placed here in a broad band of 500,000-2,000,000 mature individuals.
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 three generations, forest cover within its range reduced by c. 20-24% (Global Forest Watch [2024], based on data from Hansen et al. [2013] and methods therein). This species is most frequently found along streams and watercourses, where rates of forest loss might reasonably be inferred to 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. Accordingly, the rate of population reduction for the past three generations is set at 20-29%.
Pellorneum rostratum is known from the Sundaic lowlands, in south Tenasserim, Myanmar; peninsular Thailand; Sabah, Sarawak and peninsular Malaysia; Kalimantan (including northern islands) and Sumatra (including some offshore islands), Indonesia, and Brunei (BirdLife International 2001). Very rare resident on Singapore with sometimes many years between accepted records.
This species is found near water in lowland evergreen forest and secondary growth, as well as mangroves and peatswamp forest, up to 300 m (Eaton et al. 2021). It has also been recorded in overgrown plantations, beach-strand scrub and stunted forest on islands. It is often regarded as a riverine forest specialist and this may make it particularly acute to forest loss.
The chief threat to this species is forest loss, which has been especially rapid in the Greater Sundaic bioregion due to timber extraction and the proliferation of plantations (chiefly oil-palm and rubber). These threats are thought to have driven declines of more than 20% over the past three generations. Forest fires associated with climate change may become more frequent over time, adding an additional pressure to this species including in protected areas. There is no evidence, however, that the species is heavily trapped.
Conservation Actions Underway
This species occurs in numerous protected areas across its range, which safeguard it from more precipitous rates of population decline. No specific measure is known.
Conservation Actions Proposed
Continue to monitor rates of population decline using habitat extent as a proxy. Protect more areas of lowland forest. Instigate longer-term monitoring at some sites to determine whether there are additional threats to habitat loss.
Text account compilers
Richardson, L., Berryman, A.
Recommended citation
BirdLife International (2024) Species factsheet: White-chested Babbler Pellorneum rostratum. Downloaded from
https://datazone.birdlife.org/species/factsheet/white-chested-babbler-pellorneum-rostratum 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.