Current view: Data table and detailed info
Taxonomic note
Rheinardia nigrescens formerly regarded as a subspecies of this species but is split following Davison et al. (2020). Monotypic.
Taxonomic source(s)
Handbook of the Birds of the World and BirdLife International. 2021. Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 6. Available at: https://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v6_Dec21.zip.
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 |
|
Average mass |
- |
Population justification: A preliminary population size was created based on reported densities and likely occupancy of the mapped range, and was considered to fall in the band 10,000-19,999 individuals. However, given the exceptional levels of hunting reported in the range of the species, it is highly unlikely that an estimate derived from habitat area remains meaningful. Although the extent of the range is still large, it is strongly suspected that the population is considerably depleted (J. W. Duckworth in litt. 2018).
The population is believed to have declined and to still be declining extremely rapidly (J. W. Duckworth in litt. 2018, C. R. Robson in litt. 2020, R. Timmins in litt. 2021) though only the initial baseline for future work to quantify rates of reduction has been carried out (Gray et al. 2014). Possible extirpation has been reported from Ke Go National Park (Le Trong Trai in litt. 2018) and Dakrong Nature Reserve (references in Vu & Tran 2020). Occupancy modelling of camera-trap data strongly points to considerably depleted or potentially even extirpated populations in some forested areas but there remains frustratingly little quantification of the likely rate of reduction. However, Vu & Tran (2020) mention recent occupancy probabilities for a variety of sites based on 2016 data, including an average of 0.06-0.34 across three sites where the species was previously abundant; Bach Ma National Park, Quang Nam Saola Nature Reserve, and the Hue Saola Nature Reserve. This contrasts with an occupancy estimate of 0.68 ± SE 0.05 for these same sites surveyed in 2012 (Gray et al. 2014), coinciding with the sudden cessation of regular reports from Bach Ma National Park (Liang et al. 2018, Davison et al. 2020). Bach Ma was known as a location where the species was common (Robson et al. 1993), yet appears to have effectively disappeared within the past decade. This concurs with the concern voiced for all mid- to large-bodied vertebrates occurring in this region (Harrison et al. 2016, R. Timmins in litt. 2017, Gray et al. 2018, J. W. Duckworth in litt. 2018), with sympatric ground-dwelling species such as Owston's Civet Chtotogale owstoni and Large-antlered Muntjac Muntiacus vuquangensis assessed as at very or extremely high risk of extinction (Timmins et al. 2016a,b).
A further line of evidence comes from market inventories in Laos, where an intensive investigation in 2015-2016 did not record the species in 48 observation days despite regular records from the same markets in the late 1990s (Xayyasith et al. 2020). Currently, areas in the southern Annamites are believed to be suffering this wave of trapping and this is likely the site of the most rapid declines at present (R. Timmins in litt. 2021). This is also the last area believed to have not already suffered in this last wave of trapping.
Populations persist in protected areas where trapping pressure is currently lower, such as Song Thanh Nature Reserve (Vu & Tran 2020), Phong Dien Nature Reserve (USAID/WWF-Vietnam 2018), Bac Huong Hoa Nature Reserve (L.T. Trai in litt. 2018), at least parts of the Ngoc Linh Nature Reserve (Thinh et al. 2017) and in the Khe Nuoc Trong Forest (Manh et al. 2018, D.L. Yong & L.T. Trai in litt. 2018), as well as the Khoun Xe Nong Ma Protected Area in Laos (Mayer 2017). At each of these sites trapping is thought to have dramatically lowered densities (likely to 10% of former abundance: R. Timmins in litt. 2021), and with no effective approach to curtailing unsustainable trapping implemented in the region (Harrison et al. 2016, Gray et al. 2018) trapping intensity is very likely to increase again as other areas are depleted (J. W. Duckworth in litt. 2018, R. Timmins in litt. 2021).
Given how recently the species was described as common, and not a cause for concern (Brickle et al. 2008), the current situation strongly indicates that an extremely rapid reduction has recently taken place, and which is strongly suspected to have exceeded 80% in the past three-generations (R. Timmins & J. W. Duckworth in litt. 2021).
Trend justification: An extremely rapid rate of population reduction is suspected to have occurred, based on the extirpation of the species at some sites (Ke Go Nature Reserve [Le Trong Trai in litt. 2018] and Dakrong Nature Reserve [Vu & Tran 2020]) and sudden reduction in abundance at others (Bach Ma National Park, Quang Nam Saola Nature Reserve, and the Hue Saola Nature Reserve when comparing occupancy in 2012 [Gray et al. 2014] to that in 2016 [Vu & Tran 2020]). It is even suspected that the species may be close to extirpation in Bach Ma, a site associated with the species (Robson et al. 1993): here there are apparently no records of this highly detectable bird since 2010 (Liang et al. 2018, Davison et al. 2020).
The driver of this collapse is the most recent wave of 'industrial-level' snaring that has taken place within the past decade across much of the forested area of Central Viet Nam and Laos (Harrison et al. 2016, Gray et al. 2018). New areas are intensively trapped until target species become severely depleted: it is thought that basically all forested accessible areas have now passed through at least one phase of intensive snaring (R. Timmins in litt. 2021). Trapping continues to be viable past the point at which this species's abundance has collapsed, due to the presence of more resilient target species such as palm-civets Viverridae (R. Timmins in litt. 2021).
Habitat loss is of secondary concern, though population impacts of recent deforestation appear to be driven by increased access to forests for hunting rather than loss itself. Rates of forest cover loss have been increasing: over the past three generations (2003-2020) forest cover loss (at 30% canopy cover) totals 11.5% at an annual average of 0.59%, however the most recent 5-year mean annual rate is 1.26-1.28% (based on 2000/2010 forest cover areas: data from Global Forest Watch 2021). If this rate continues, over the three generation period from 2016 to 2033 forest loss within the range of the species would total 21.4%.
The overall rate of population decline is not precisely estimated. However, given the extremely severe pressure from snaring throughout the range over the last two decades, apparent extirpations and rapid loss of abundance reported from multiple sites, the suspected rate of population reduction is believed to have been extremely rapid over the past and current three-generation periods, exceeding 80% (R. Timmins & J. W. Duckworth in litt. 2021). The pressures are considered likely to continue in the future (S. Mahood in litt. 2021, J. W. Duckworth in litt. 2021, R. Timmins in litt. 2021) but the very rapid erosion of abundance is thought to already have occurred, hence a future rate of decline is suspected to be at a slightly lower rate. Focused protection within the core zones of some protected areas may also allow the recovery of some populations (R. Timmins in litt. 2021, but it appears very unlikely that the species will recover a significant proportion of its former abundance in the absence of effective anti-trapping strategies (Gray et al. 2018).
Country/territory distribution
Important Bird and Biodiversity Areas (IBA)
Recommended citation
BirdLife International (2025) Species factsheet: Annamite Crested Argus Rheinardia ocellata. Downloaded from
https://datazone.birdlife.org/species/factsheet/annamite-crested-argus-rheinardia-ocellata on 08/01/2025.
Recommended citation for factsheets for more than one species: BirdLife International (2025) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 08/01/2025.
