Data Zone
Justification of Red List category
This species qualifies as Vulnerable because it is restricted to low-lying forest in a region where this habitat type is being cleared and degraded at such a rate that rapid and continuing population declines are likely.
Population justification
The global population size has not been quantified but is believed to be large given the range and frequency of records in suitable habitat. It is a forest-dependent species and appears to occur only in primary forest (eBird 2022). Within its range, the rate of forest conversion to plantations, primarily oil palm, has been very rapid over the past few decades (per Global Forest Watch 2022). There are recent records from remaining forested areas across the range, however the extent of suitable habitat is now considerably smaller than three generations ago. Where habitat is secure the species continues to be regularly observed (eBird 2022), though observing the species away from protected areas is becoming increasingly difficult. In Thailand, all recent records are in (/the vicinity of) the Hala Bala Wildlife Sanctuary (Treesucon and Limparungpatthanakij 2018) and the population there must now be very small. Almost all records in Malaysia now come from protected areas or forest concessions, and the population is thought to be declining rapidly in lowland Indonesia, although here (especially in Kalimantan), there are large tracts of suitable habitat remaining. Forest loss is much lower in Brunei, where impacts on the species may be much less severe and much of the forest here is likely to be suitable for this species. Overall, the population is considered highly unlikely to meet or approach the population size threshold for listing as threatened (<10,000 mature individuals) although this requires confirmation.
Trend justification
The species is most abundant in the undergrowth of intact primary lowland forest. Consequently the population impact of forest cover loss is expected to be equal to or greater than the rate of loss. In the three generations (15.15 years; Bird et al. 2020) to 2021, forest cover in this species' range was reduced by 24–27%, depending on the forest cover thresholds set (Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein). This value does not account for the impact of forest degradation, hence the population rate of reduction from habitat loss is likely to be greater than this. Similarly, since the species is most regularly encountered in low-lying forest (eBird 2022), where losses are greater, the overall rate of population reduction is suspected to be equivalent to c.25–35% over the last three generations. This rate is also precautionarily projected over the next three generations, although beyond that rates of loss may slow as the percentage area of forest outside protected areas diminishes.
Centropus rectunguis occurs from extreme southern Thailand, through Peninsular Malaysia to Malaysian Borneo (Sabah and Sarawak), Brunei and Indonesia (Kalimantan and Sumatra) (BirdLife International 2001).
It appears to be generally restricted to the undergrowth of lowland evergreen forest, where it occurs at low population densities; occurs to 600 m (Eaton et al. 2021).
Forest destruction in the Sundaic lowlands of Indonesia and Malaysia has been extensive, for timber and conversion to agriculture. In particular the rapid expansion of oil palm has driven the conversion of the majority of remaining lowland forest in the region. Between 2006 and 2021, tree cover was reduced in its range by 24–27% (Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein). Most of this loss has occurred within the lowlands, where the highest densities of the species would be expected. Moreover, the impact of forest degradation will have added to rates of decline. Associated with the forest loss has been an increase in fire frequency, extent and severity, particularly during strong El Nino events (as in 1998). While the species can use secondary growth and higher elevations, the extent of the threats is such that this species' population is likely to be declining rapidly.
Conservation Actions Underway
None is known, however this species occurs in a number of protected areas throughout its range.
Conservation Actions Proposed
Conduct surveys by listening for its call to investigate its altitudinal distribution, ecological requirements and the levels of threat it faces and thereby determine whether any specific conservation measures are required. Provide adequate support for the conservation of relevant lowland protected areas. Lobby for reduced logging of lowland forest in the Sundaic region.
43 cm. Medium-large, forest-dwelling coucal. Predominantly black, glossed purplish blue, with chestnut wings and mantle. Iris red, bill and legs black. Similar spp. Greater Coucal C. sinensis is larger, with proportionately longer tail, black plumage slightly less violet glossed. Voice Ponderous descending sequence of around five deep buup notes, like call of C. sinensis but deeper, slower, more resonant. Hints Search undergrowth of deep forest.
Text account compilers
Berryman, A.
Contributors
Robson, C. & Edwards, D.
Recommended citation
BirdLife International (2024) Species factsheet: Short-toed Coucal Centropus rectunguis. Downloaded from
https://datazone.birdlife.org/species/factsheet/short-toed-coucal-centropus-rectunguis on 26/11/2024.
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 26/11/2024.