Data Zone
Justification of Red List category
This species occupies only a small range in East Java, where it is known from only three sites. Combined, these probably comprise only a small number of Locations, considering trapping as the main threat (although habitat loss at the lowest elevations of its range is also likely contributing to continuing declines). For these reasons, it is assessed as Vulnerable.
Population justification
Most of this species' range is not frequently visited by professional and amateur ornithologists, obscuring details of its abundance. In surveys of Mt Ijen, Mittermeier et al. (2014) found it to be fairly common (defined as 4–10 individuals encountered per day), while Eaton et al. (2021) described it as scarce. The total area of the mapped range is c.2,500 km2, of which only c.2,000 km2 now remains forested (Global Forest Watch 2023). Other range-restricted Arborophila partridges occur at low densities (Bo et al. 1998, Chhin et al. 2019) and given the trapping pressure on this species (Nijman 2022) that is likely to be depressing numbers, a density of 2–10 mature individuals (accounting too for occupancy) is precautionarily suspected. The global population size of this species is therefore suspected to number 4,000–20,000 mature individuals. Given the description of abundance given by Mittermeier et al. (2014) and reports of the numbers being traded by Nijman (2022) with no evidence of total population collapse, the upper range (10,000–20,000) of this coarse estimate is suspected of being the most accurate. Assuming the species is evenly distributed across its range, Mt Ijen probably hosts the largest subpopulation (approximately 50% of its global population size).
Trend justification
Inferred to be declining because of habitat loss and trapping. In the past three generations (16 years: 2007–2023), approximately 5.2% of forest (>50% canopy cover) has been lost from within the mapped range of A. orientalis (Global Forest Watch 2023, based on data from Hansen et al. (2013) and methods disclosed therein). As a forest-dependent species, this is thought to have had a direct impact on the population size of A. orientalis, and has likely caused a population reduction of at least 5% over the same time period. Moreover, there is evidence of trapping on a scale that is unlikely to be sustainable. Nijman (2022) estimated that approximately 700 individuals are sold each year in markets on Java and Bali. Given the estimated population size of 10,000-20,000 mature individuals used here, this level of trade is suspected to be unsustainable, and causing further ongoing declines. However, in the absence of robust demographic data, plausible lower and upper bounds are difficult to model. Overall, the species is suspected of having declined by 5–20% over the past three generations. In the absence of a clear slowing or amelioration of the current threats, this rate of decline is also suspected to occur in the window 2010–2026, and in the next three generations (2023–2039).
Endemic to the eastern part of East Java, Indonesia, where it is known from only three areas (west to east): Dataran Tinggi Hyang (Yang Highlands), Meru Betiri and Mt Ijen.
Inhabits the interior of montane evergreen forest between 600 m and 2,200 m (Eaton et al. 2021).
The main threats to this species are habitat loss and trapping. In the past three generations (16 years: 2007–2023), approximately 5.2% of forest (>50% canopy cover) has been lost from within the mapped range of A. orientalis (Global Forest Watch 2023, based on data from Hansen et al. (2013) and methods disclosed therein). The main drivers of this loss are timber extraction and agricultural expansion. As a forest-dependent species, this is thought to have had a direct impact on the population size of A. orientalis, and has likely caused a population reduction of at least 5% over the same time period. Moreover, there is evidence of trapping on a scale that is unlikely to be sustainable. Nijman (2022) estimated that approximately 700 individuals are sold each year in markets on Java and Bali. Given the estimated population size of 10,000–20,000 mature individuals used here, this level of trade is suspected to be unsustainable, and causing further ongoing declines. There is no evidence that either of these threats have ceased.
Conservation Actions Underway
A small part of its range is protected, comprising: (1) Dataran Tinggi Yang [c.140 km2]; and (2) Kawah Ijen [c.25 km2] (Savini et al. 2021, UNEP-WCMC and IUCN 2023). However, the effectiveness of these designations (especially from trapping) is unknown. Captive populations are held, including one at Prigen Conservation Breeding Ark (PCBA), East Java.
c.28cm. Stocky, short-legged, forest-dwelling partridge. Generally grey, barred darker on lower back and tail, with blackish crown and nape, and conspicuous whitish forehead, cheeks and throat. Wings brownish with dark tips to inner wing feathers and rufous on flight feathers. Black bill and red legs. Reddish orbital skin. Voice A series of "wu" notes gradually increasing in volume; or a disyllabic "whur-hu", often in duet and increasing in volume (Eaton et al. 2021). These vocalisations are indistinguishable from those of A. javanica and the two respond to playback of each other's calls (Mittermeier et al. 2014).
Text account compilers
Berryman, A.
Contributors
Nijman, V. & van Balen, B.S.
Recommended citation
BirdLife International (2024) Species factsheet: White-faced Partridge Arborophila orientalis. Downloaded from
https://datazone.birdlife.org/species/factsheet/white-faced-partridge-arborophila-orientalis 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.