Data Zone
Justification of Red List category
This species is categorised as Near Threatened because it is restricted to forest in a region where deforestation is occurring at a rapid rate, implying that it is experiencing ongoing population declines that are at least moderately rapid. It is not considered more threatened because it shows some tolerance of habitat degradation and ranges into montane areas where forest is typically more secure.
Population justification
The population size of this species has not been quantified, although the species is typically described as uncommon (Wells 1999, Mann 2008, Eaton et al. 2016).
Trend justification
The population is suspected to be declining because of forest loss throughout its range. Over the past three generations (12.2 years; Bird et al. 2020), forest loss in this species' range has been equivalent to 21–23% (Global Forest Watch 2022, using data from Hansen et al. [2013] and methods disclosed therein). Because this rate was similar between 2016 and 2020, with little indication this will slow in the future, the same rate is suspected to occur over the next three generations. As a forest-dependent species, the population is suspected to be declining at a rate broadly similar to the that of forest loss. It may additionally be impacted by habitat degradation and fragmentation.
Hierococcyx vagans is confined to the Sundaic lowlands, from south Tenasserim, Myanmar, peninsular Thailand, south Laos, Sabah, Sarawak and Peninsular Malaysia, Singapore, Brunei, Kalimantan and Sumatra Indonesia, where it is generally uncommon (BirdLife International 2001). Although the holotype was reportedly collected in Java, there has been no record here since (Eaton et al. 2016).
It occurs in evergreen forest, forest edge and secondary forest; especially lower hill slopes, alluvial forest and bamboo forest up to 900 m (Mann 2008, Eaton et al. 2016). It is a brood parasite.
Rates of forest loss in the Sundaic lowlands have been extremely rapid, owing partly to the escalation of illegal logging and land conversion, with deliberate targeting of all remaining stands of valuable timber including those inside protected areas (Hansen et al. 2013, Global Forest Watch 2022). Forest fires have previously had a damaging effect (particularly in 1997-1998) and may do so again in the future. The magnitude of these threats may be allayed partially by this species' tolerance of hill forest, which is under less pressure from logging and agricultural conversion.
Conservation Actions Underway
No targeted conservation actions are known for this species although it benefits from the wider protection of Sundaic lowland forest.
Conservation Actions Proposed
Conduct repeated surveys across the range to estimate population trends. Ensure the protection of remaining tracts of primary lowland rainforest throughout the range.
Text account compilers
Berryman, A.
Recommended citation
BirdLife International (2024) Species factsheet: Moustached Hawk-Cuckoo Hierococcyx vagans. Downloaded from
https://datazone.birdlife.org/species/factsheet/moustached-hawk-cuckoo-hierococcyx-vagans on 23/12/2024.
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 23/12/2024.