Data Zone
Justification of Red List category
This spectacular, ground-dwelling bird is endemic to the forests of Indochina, where industrial-level snaring for bushmeat compounded with rapid rates of forest loss have caused very rapid declines in its population over the past three generations (18 years). It is therefore listed as Endangered.
Population justification
The global population size has not been quantified.
Previously the species was considered uncommon in lowland forest throughout the range (del Hoyo et al. 1997), but at the time of that judgement the species was locally common in some areas, e.g. Lao PDR (Thewlis et al. 1998) and, probably, northern Cambodia. In recent years it has been only sparingly and very locally recorded, despite significant camera-trapping where it can have reasonably been expected (Gray et al. 2017, Timmins et al. in press)—it is therefore very likely that the species' global population is now much smaller than it was three generations ago. The current situation is discussed for each range state below.
At one time, Lao PDR probably hosted a majority of this species’ global population (simply by virtue of available habitat area) but the last couple of decades of intense snaring pressure (see Population Trend justification) have now rendered it scarce and highly local. As detailed by Timmins et al. (in press), there are large areas of suitable habitat where the species should reasonably be expected, but recent survey effort has failed to find them. Only in the subcatchment of the Nam Ngiep 1 Hydropower Project (NNP1) has the species in Lao PDR proved common recently (Vongkhamheng et al. 2015), a site that Timmins et al. (in press) argues ‘typifies a site pre-snaring’.
In Cambodia, Goes (2013) considered it a 'probably fairly common and widespread resident' and detailed records from across much of the country; it has probably declined steeply since with recent surveys where it might have been expected (e.g. Gray et al. 2017, Auda 2023), but recent records include observations from Phnom Aural and Changkran Roy (eBird 2024).
Carpococcyx renauldi remains locally common and regularly encountered from scattered localities in Thailand (e.g. Khao Yai NP, Phu Khieo WS, Phu Chong–Na Yoi NP; eBird 2024) and these probably represent the most secure populations of this species in the long-term.
Viet Nam historically probably hosted a large population but there are no traceable recent records (Timmins et al. in press, eBird 2024) and it is likely that the population here has been negligible this century.
Trend justification
The species is inferred to be declining, probably rapidly, in response to intense snaring pressure in large parts of its range and habitat loss. Although its secretive ground-dwelling lifestyle makes it difficult to find and it may be under-recorded (and this is what presumably allowed it to remain relatively common in areas of Lao PDR with intensive hunting with projectile and dogs, but not dense snaring, for decades), the increasing threat from hunters using cable-snaring suggests that the species is genuinely now very rare and decreasing, with Timmins et al. (in press) determining that there is 'growing evidence of global widespread population collapse of this species'. The rate of past decline is difficult to estimate, and likely differs between countries, but overall is strongly suspected to have been very rapid. Range states are discussed individually below.
Status in Lao PDR is reviewed in detail by Timmins et al. (in press), who consider the species to have declined rapidly over the past two decades in response to snaring pressures and, to a much lesser extent, habitat loss. Evidence to support this largely rests on the absence of the species from multiple large areas of well-surveyed habitat deemed suitable, and the persistence of the species only at sites that have been spared from the 'wave of industrial level snaring', to which the species appears especially sensitive (probably directly, but also perhaps indirectly via the loss of ungulates to which this species might have had a closely tied foraging ecology). There is also more direct evidence for population collapse: for example, the species was 'locally common' on the Nakai Plateau during surveys in the 1990s (e.g. Thewlis et al. 1998, Dersu 2008) but by 2009-2011 surveys was apparently absent (Timmins et al. in press). Similarly, previous surveys of Nam Kading found the species locally common (Thewlis et al. 1998, Timmins and Robichaud 2005), but a repeat in May 2019 found it provisionally from only one locality (Timmins et al. in press). Given the range of (sometimes degraded) forest types the species has been recorded from, Timmins et al. (in press) consider habitat modification an 'unlikely' contribution to the suspected rapid declines. Nonetheless, modification of lowland forests (<500 m) in Lao PDR has been nearly total (Grantham et al. 2020, Global Forest Watch 2024, Timmins et al. in press) and this has likely had a secondary direct impact, as well as granting hunters improved access to once remote blocks of forest.
While the species may still be common in some protected areas in Cambodia, it has probably declined rapidly overall and the absence of recent records is suggestive of a situation that may soon mirror that of Lao PDR. Rates of forest loss here have been among the most rapid in the world (Global Forest Watch 2024), sufficient to drive rapid declines on their own in this forest-dependent species, but also increasing the accessibility to hunters of the remaining evergreen forest. In the Cardamom Mountains in the south of the country, the amount of habitat remains large and must have once held a large population (Goes 2013). However, the level of snaring has, in the past 20 years, increased considerably in the lower areas of the Cardamoms, and recent camera-trap surveys failed to detect the species (Gray et al. 2017). Recent camera trap surveys in Prey Lang (Auda 2023) failed to detect it, despite being a landscape where they would been expected (S. Mahood in litt. 2023).
The most secure populations of this species must now be hosted in Thailand, where majority of recent records (eBird 2024) refer to populations that are safeguarded by Thailand's protected area network, in which there is currently minimal hunting and negligible habitat loss and degradation (Grantham et al. 2020, Global Forest Watch 2024). Despite losses that are likely considerable compared to a historical baseline, the current population trend here is probably stable, and probably has been for the last 15 years or more.
In Viet Nam, once possibly quite common but there are no recent records (Timmins et al. in press); however most declines probably occurred before the current three-generation window and therefore will not have had a material impact on the global trend in this time period.
Consolidating national trends into a global one is hampered by imperfect knowledge of local abundances three generations ago. Accordingly, the band of population reduction is set broadly to 30-79% over the past three generations (i.e. 2006-2024), with a best estimate of 50-79%. This latter conclusion follows the principle that up to the early 2000s, Lao PDR and Cambodia combined held a vast majority of the world's population (based simply on the area of suitable habitat available to them), with very rapid population declines in both countries (and near-collapse in Lao PDR), it is therefore reasonable, and highly probable, that the global population has more than halved in the past three generations. With very little chance of immediate recovery, the same rates of reduction are used for the window 2008-2026 (thus also qualifying the species for Endangered under Criterion A4). Future rates of decline are highly uncertain, however it is likely that they will be lower than 50%, with a much larger proportion of the population now lying in Thailand (where birds are broadly safe from snaring barring a collapse of the Thai protected area system), meaning that the contribution of Lao and Cambodian population trend to the overall global picture will be much smaller than in the last three generations.
Carpococcyx renauldi is endemic to South-East Asia. In Cambodia, relatively widespread (at least formerly) in semi-evergreen and hill evergreen forests, including in the Cardamom mountains (Goes 2013). In Lao PDR, historically probably widespread throughout what Timmins et al. (in press) define as the 'Lao Lowlands' as well as the foothills and lower slopes of the Annamites, and probably very marginally at the southern edge of northern Lao PDR; now, however, the species is extremely localised (Timmins et al. in press). In Viet Nam its status is not well known but it was probably widespread in the country's south and centre, with historical records stretching north to at least Ke Go (eBird 2024). In Thailand the species at one time occurred as far north as Phayao province (Robson 1986) but now confined to the country's east, with recent records from Khao Yai NP, Khao Khitchakut NP, Khao Ang Rue Nai WS, Phanom Dong Rak WS, Huai Sala WS, Phu Khieo WS, Thung Salaeng Luang NP and Phu Chong–Na Yoi NP (eBird 2024).
In Cambodia, inhabits semi-evergreen and hill evergreen forest, mostly in the lowlands but recorded to 1,450 m in the Cardamom mountains (Eames et al. 2002, Goes 2013). In Lao PDR, records span a range of wooded habitats including semi-evergreen forests, open savanna-like dipterocarps forest, highly degraded semi-evergreen forests, regenerating forest with high bamboo abundance, and mountain foothill semi-evergreen forests, chiefly below 500 m. However, it has been recorded in semi-evergreen montane forests to over 1,000 m, exceptionally to 1,500 m, and locally in heavily degraded sections of Annamitic forest to at least 800 m (Timmins et al. in press and references therein). Combined these observations suggest a degree of habitat plasticity that that seems at odds with its localised distribution; in the north, for example, it appears to be confined to the Mekong low-lying hills in Vientiane and Xaignabouly provinces (Duckworth et al. 1999, Timmins et al. in press), and it appears to be entirely absent from Myanmar, the Thai-Malay Peninsula and far northern Thailand or Viet Nam, or China at all. Timmins et al. (in press) concluded that taking all observations into account, there are likely some 'quirks' of the species' ecological niche and 'although not an obligate ’lowland’ species, elevation and factors associated with elevation could well be important, and equally that moister microhabitats may also be significant'.
Like all ground-cuckoos, this is a strictly terrestrial species which renders it highly vulnerable to snaring. Its diet includes insects, small reptiles, small mammals, and small birds (Payne and de Juana 2020).
The species is heavily threatened by the rapid expansion of industrial drift-fence cable snaring, which has taken place since the late 1990s and early 2000s. Snaring is particularly affecting parts of the species' range in Viet Nam, Lao PDR and, to a slightly lesser extent, Cambodia (Timmins et al. in press). Especially lowland forests are regularly frequented by hunters (Gray et al. 2017). While the species is targeted directly by hunters for its meat, it is also taken as a 'bycatch' in snares set out for ungulates (Grey et al. 2018). In addition to the threat from snaring, the species may also have been affected by the reduction in large mammal and primate populations, as it apparently forages in areas disturbed by these animals (Timmins et al. in press).
Although the habitat has been recorded in a range of forest types, including those that are heavily degraded, it is inevitable that the widespread loss of lowland forests in Indochina (often resulting in total clearance, or conversion to villages or plantations) has compounded population declines, even if it hasn't been the principal driver of them. Moreover, the extensive degradation of Lao PDR's forests (Grantham et al. 2020) has led to a considerable expansion of the road network (plus logging tracks) combined with increased motorcycle ownership, resulting in a massive rise in accessibility to hunters, as well as the more direct impacts of habitat conversion (Timmins et al. in press).
Conservation Actions Underway
Occurs in numerous protected areas throughout its range (UNEP-WCMC and IUCN 2024, eBird 2024, Timmins et al. in press); while in some countries these are likely to be highly effective at safeguarding populations of this species from the effects of habitat loss and hunting (e.g. Thailand), in others they have largely been ineffective at doing so (Timmins et al. in press).
Conservation Actions Proposed
The most urgent priority for this species should be determining its status in recently unsurveyed national parks, particularly in Lao PDR (Timmins et al. in press). Areas where conservation measures could reasonably be implemented to protect the species should be prioritised for searches; deployment of autonomous recording units (ARUs) or camera traps are likely to prove the most effective survey methods for this highly elusive species, and reduce the risk of false negative results. Protecting this species will be difficult, but will require the adequate resourcing of enforcement as well as community engagement to protect remaining populations, all of which remain very vulnerable to extirpation by trapping.
Text account compilers
Berryman, A.
Contributors
Gray, T.N.E., Mahood, S., Yong, D., Ekstrom, J., Butchart, S. & Timmins, R.J.
Recommended citation
BirdLife International (2024) Species factsheet: Coral-billed Ground-cuckoo Carpococcyx renauldi. Downloaded from
https://datazone.birdlife.org/species/factsheet/coral-billed-ground-cuckoo-carpococcyx-renauldi on 23/11/2024.
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 23/11/2024.