Justification of Red List Category
This spectacular pheasant is suffering from the twin threats of habitat loss and hunting throughout its extensive range. It is suspected that the rate of population reduction is more rapid than previously thought and the species has consequently been assessed as Vulnerable.
The total population has been estimated to number more than 100,000 individuals, based on available habitat, but it is undergoing a steep decline in most of the range, especially Sumatra (McGowan and Kirwan 2020) but also southern Thailand (Dawrueng et al. 2017), and the current population size is likely to be smaller. Previously known from more than 130 sites across the Sundaic lowlands (McGowan et al. 1998), it is certainly very scarce now at a number of these, such as Way Kambas National Park, and likely to be absent from some. In Indonesia, it is only considered secure in reserves and well-managed forests (McGowan and Kirwan 2020).
There are no data on population trends; however, the species is suspected to be in decline at a moderately rapid rate, owing to hunting and habitat loss.
Argusianus argus is confined to the Sundaic lowlands, where it is recorded from south Tenasserim, Myanmar, peninsular and south-west Thailand, Sabah, Sarawak and Peninsular Malaysia, Brunei (extirpated from many areas), Kalimantan and Sumatra, Indonesia (BirdLife International 2001). It is generally uncommon, although this species has probably not declined very rapidly because it ranges up to elevations where forest loss is less severe and occurs it in selectively logged sites. Densities recorded in south-western Sumatra ranged from 0.9 to 3.7 birds/km2 (Winarni et al. 2009).
It occurs in tall, dry, lowland primary, secondary and logged forests, up to 1,300 m, but principally, below 900 m (BirdLife International 2001, Dinata et al. 2008). It is much sparser in deciduous forest and rare to absent from lowland peat swamp and white-sand heath forests. A recent study in Sumatra, utilising radio-tracking, habitat sampling, camera trapping and transect surveys found that territories averaged 14.5 ha, used mostly by resident males, who showed a preference for undisturbed forest (Winarni et al. 2009). Both sexes show a preference for intact forest with large trees and an open understorey. The species's diet includes fruits, seeds, flowers, leaf buds and invertebrates (Winarni et al. 2009).
Forest destruction in the Sundaic lowlands of Indonesia and Malaysia has been extensive and persistent. Within the mapped range of Great Argus, 16.4% of forest has been lost in 16.2 years, equivalent to 24.3% over three generations (Tracewski et al. 2016, Symes et al. 2018). Forest is being lost to a variety of factors, including the escalation of logging and land conversion, with deliberate targeting of all remaining stands of valuable timber including those inside protected areas, plus forest fires recurring with increasing frequency across formerly intact forest. The rapid expansion of oil palm plantations has predominately been at the expense of forest clearance (Austin et al. 2017). At present, less than 13% of Sumatra's original lowland forest cover remains (Winarni et al. 2009). Several studies demonstrate that Great Argus show a strong preference for primary or unlogged forest (Nijman 1998, Edwards et al. 2011) and has little ability to disperse into disturbed habitat (Winarni et al. 2009). While the species occurs in logged forest, densities are dramatically lower after each logging round (Edwards et al. 2011), as they are in young versus old secondary forest, and old secondary forest versus primary forest (Nijman 1998). Within logged forest remnants, the species still demonstrates a positive correlation with forest intactness (Jati et al. 2018). Winarni et al.(2005) found the species absent from 11 of 13 fragments ranging from size between 2.5 to 50 km2, with varying degrees of isolation, whereas Great Argus was present in all intact forest areas greater than 50 km2. Rapid forest loss has created many fragmented regions, in which it is unlikely the species can persist and if it does, it will do so at much reduced densities.
Declines are compounded by trapping for the cage-bird industry (Symes et al. 2018), potentially for the sale of feathers and for food (Novriyanti 2019). The species was assessed as being at high risk from trapping, and Symes et al. (2018) predicted that could lead to an additional 52.8% decline over three generations. However, the species does not appear to be highly traded as a cagebird, rather for ceremonial decoration and for food. While there will be an additional impact from hunting it is not likely to exceed the impact of habitat loss for the species. The impacts of anthropogenic threats may be compounded by pressures from drought events, such as those linked to the El Niño Southern Oscillation (ENSO) (Winarni et al. 2009).
Conservation Actions Underway
CITES Appendix II.
Text account compilers
Ding Li, Y., Iqbal, M. & Sa-ar, I.
BirdLife International (2021) Species factsheet: Argusianus argus. Downloaded from http://www.birdlife.org on 07/12/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 07/12/2021.