Data Zone
Justification of Red List category
This species has been severely impacted by the intensive industrial-level snaring that has taken place in the past decade. In tandem with increasing rates of forest cover loss allowing greater access to trappers and reducing the extent and quality of forested habitat within the range, this is suspected to have driven an extremely rapid loss of abundance in this formerly common species. The species is classified as Critically Endangered.
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).
Rheinardia ocellata is found along the Annamite mountain chain in central and southern Viet Nam and neighbouring eastern Laos, between the Nghe An province and the Da Lat Plateau in southern Viet Nam. Previously it was readily recorded within forest in this range, but the impact of intensive snaring has depleted populations severely such that it is now absent or close to extinction at previously occupied sites.
It is resident in primary and secondary evergreen forest from sea-level up to 1,500 m, and up to1,700-1,900 m on the Da Lat Plateau. The highest densities are from moist primary forest in lowlands up to c. 900 m. It has been recorded from degraded forest habitats, including active logging concessions (N. Brickle in litt. 2004), however recent occupancy modelling shows a significant association of the species with intact, closed-canopy forest (Gray et al. 2014). It is plausible that this finding actually reflects the pattern of hunting intensity rather than a species preference, as within an area of lower hunting pressure forest cover was not a strong predictor of occurrence (Vu and Tran 2020).
The most serious threat to the species stems from high levels of hunting, mostly via the use of snares. The species is hunted mainly for its meat, but also for the pet trade (McGowan and Kirwan 2020). Especially in the lowland forests throughout Viet Nam and Laos, snaring has intensified tremendously since the early 2000s (Harrison et al. 2016, Gray et al. 2018, J.W. Duckworth in litt. 2018, R. Timmins in litt. 2021). There are no effective measures in place to reduce the level of snaring within the species's range (Gray et al. 2018, J.W. Duckworth in litt. 2018), hence the population decline is very likely to continue.
The rate of forest cover loss within the range of the species is increasing (Global Forest Watch 2021). Over the past three generations (2003-2020) forest cover loss 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%. This is sufficient to be driving a moderate population reduction in itself, but the larger issue is that this forest cover loss correlates with increased access to remaining forest and consequently extent of trapping.
Conservation Actions Underway
CITES Appendix I. It occurs in several protected areas, including at least 10 nature reserves in Viet Nam, at least two designated and two proposed National Biodiversity Conservation Areas in Laos. Anti-snaring patrols operate in several protected areas in Viet Nam (Gray et al. 2018). Taxonomic relationships between this species and R. nigrescens have been investigated resulting the separation of the two as distinct species with separate conservation requirements (Davison et al. 2020).
Male 190-239 cm, female 74-75 cm. Large pheasant with enormous tail. Male blackish-brown, peppered whitish all over. R. o. nigrescens has buff supercilium and throat and drooping, blackish-brown and white crest. R. o. ocellata has shorter, mostly brownish crest, white supercilium and throat, chestnut-brown foreneck, more numerous, smaller, buffier upperpart markings and more dark chestnut and grey on tail. Female is smaller, shorter-tailed and warm brown with blackish and buff bars, speckles and vermiculations. Somewhat paler below. Voice At dancing grounds, very loud woo'o-wao. Also series of far-carrying oowaaaa phrases.
Text account compilers
Martin, R., Hermes, C., Murray-Watson, R.
Contributors
Benstead, P., Brickle, N., Davidson, G., Duckworth, J.W., Eames, J.C., Keane, A., Mahood, S., Taylor, J., Trai, L., Wells, D.R. & Yong, D.
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.