Current view: Data table and detailed info
Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.
IUCN Red List criteria met and history
Red List criteria met
Red List history
Migratory status |
not a migrant |
Forest dependency |
high |
Land-mass type |
shelf island
|
Average mass |
- |
Population justification: A global population size has not been robustly estimated previously, but is here considered to probably fall between 5,000-40,000 mature individuals. In the Puerto Princesa Subterranean River National Park, Mallari et al. (2011) estimated densities in primary, advanced secondary, and early secondary of, respectively, 11.2, 4.8 and 1.5 birds/km2.
The extent to which these densities are representative of suitable habitat across the island is unknown, but it is acknowledged that while the species has been recorded to 1,350 m, only in the extreme lowlands (<400 m) does it appear to be regularly encountered (eBird 2023), and it was at these elevations that Mallari et al. (2011) conducted their fieldwork.
The area of suitable forest within its elevational range is difficult to define, but is here estimated at a maximum of 3,500-5,000 km2 (using a range of canopy cover and intactness scenarios from Hansen et al. [2013], Global Forest Watch [2024] and Grantham et al. [2020]), of which only 30-70% is here crudely estimated to be occupied, in an attempt to account for densities at different elevations, small isolated fragments unlikely to be occupied, unsuitable terrain etc. Applying densities spanning 4.8-11.2 mature individuals to these figures gives a broad range of (rounded) 5,000-40,000 mature individuals. An approximate midrange (10,000-30,000) is here chosen as the most likely.
Trend justification: Thought to be declining rapidly in response to habitat loss, with primary lowland forest bearing the brunt of Palawan's forest loss caused by logging, agricultural expansion and, in some years, typhoon damage.
In the past three generations (11 years: 2011-2022), forest cover within this species' mapped elevational range decreased by c.20%, with a considerable increase in 2022, when the effects of Super Typhoon Odette (also known as Typhoon Rai), which hit the island in December 2021, were first realised in remote sensing data. Losses have been most acute in the extreme lowlands (<200m), where losses were approximately 23-25%, and it is these elevations that are suspected to host the majority of this species' population. Given this species is highly forest dependent (see Mallari et al. 2011), rates of forest cover loss are suspected to be the best proxy for rates of population trend. Accordingly, over the past three generations, this species is suspected of having declined by 20-29%.
Rates of average forest loss have increased since c.2016. While a substantial amount was lost because of Super Typhoon Odette, even before this annual rates 2016-2021 were almost a third higher than in 2011-2016. Accordingly, if this doesn't cease or slow (and especially if another powerful typhoon hits in this window), then rates of forest cover loss, and hence population reduction, are suspected to be higher in the window 2016-2027. Similarly, future rates of decline over the next three generations (11 years: 2023-2034) are precautionarily suspected to be greater than the past. Accordingly, rates of population reduction between 2016 and 2027, and between 2023 and 2034, are suspected to be 25-35%.
Country/territory distribution
Important Bird and Biodiversity Areas (IBA)
Recommended citation
BirdLife International (2024) Species factsheet: Falcated Wren-babbler Ptilocichla falcata. Downloaded from
https://datazone.birdlife.org/species/factsheet/falcated-wren-babbler-ptilocichla-falcata 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.