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 scarce to locally common (Wells 1999, 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 three generations, forest cover within its range reduced by c. 18-22% (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. Accordingly, the rate of population reduction for the past three generations is set at 20-29%.
Chrysophlegma humii occurs from southernmost Myanmar (Tenasserim) and south peninsular Thailand through Peninsular Malaysia, Sabah and Sarawak, Indonesia (Sumatra, Bangka Island and Kalimantan) and Brunei Darussalam (Winkler et al. 1995). Presumed extinct in Singapore, where last recorded 1949.
It inhabits primary evergreen or moss forests in the lowlands and mountains, especially wetter parts and areas with dense understorey and large trees (Winkler et al. 1995, del Hoyo et al. 2002). The species also occurs in overgrown clearings, dense forest edge, occasionally the landward edge of mangroves and has been rarely seen in dense, tall secondary growth and scrub or cultivated land (Winkler et al. 1995, del Hoyo et al. 2002). It occurs below 1,000 m in Thailand, up to 1,200 m in Malaysia and up to 2,100 m in the Greater Sunda Islands (Eaton et al. 2021). Breeding has been recorded in March and April in Peninsular Malaysia and between February and June in Borneo; the nest is excavated in dead stubs (Winkler et al. 1995). Its diet predominantly comprises insects with occasional berries foraged by gleaning and probing in the lower and middle storeys (3-15m), sometimes with mixed-species flocks (Winkler et al. 1995).
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
Berryman, A., Richardson, L.
Recommended citation
BirdLife International (2024) Species factsheet: Chequer-throated Yellownape Chrysophlegma humii. Downloaded from
https://datazone.birdlife.org/species/factsheet/chequer-throated-yellownape-chrysophlegma-humii 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.