Data Zone
Justification of Red List category
This species has a large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over three generations). The population size is unknown, but is not suspected to be sufficiently small to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Population justification
The population size of this species has not been quantified. However, forest in its mapped range covers c.140,000 km2, such that its population is likely to be relatively large, even if only a small proportion of this is occupied. In some areas (especially Sabah) the species appears to be rather scarce, however in Sarawak it can be locally very common (Mann 2008, Bruce 2020, eBird 2022).
Trend justification
Although there is little doubt that this species' preference for submontane forest buffers it from the worst of Sundaic forest loss, nonetheless it is likely to be impacted, especially at the lower limits of its elevational range. Vast swathes of habitat do remain however, especially in Kalimantan. In the three generations (12.4 years; Bird et al. 2020) to 2021, forest cover in this species' range was reduced by 5-6% (Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein). This is thought to be broadly representative of population declines, which may in fact be steeper than remote sensing data alone suggest. The population decline is therefore suspected to have been equivalent to 5-9% in the past three generations and, based on slightly accelerated (equivalent to 7-8% losses) deforestation between 2016 and 2021, to 5-15% in the next three generations.
Calyptomena hosii is patchily distributed in Sabah and Sarawak, Malaysia and Kalimantan, Indonesia (BirdLife International 2001, Mann 2008).
It occurs in the upper zone of mixed dipterocarp forest on hill slopes, and in lower montane forest. Most records are between 600 and 1,220 m, occasionally up to 1,680 m (Mann 2008).
Forest loss in the Sundaic region, mainly for conversion to plantations and livestock pastures, has been rapid and widespread, and is likely to have affected the lower altitudinal range of this species (per Global Forest Watch 2022). However, its presence in sloping montane forest suggests that it is not imminently threatened, although logging activities in these habitats are increasing.
Conservation Actions Underway
No targeted conservation actions are known for this species, although it occurs in a number of protected areas.
Conservation Actions Proposed
Conduct repeated surveys across the species' range to determine the magnitude of declines and rates of range contraction. Conduct ecological studies to improve understanding of its precise habitat requirements, tolerance of secondary habitats and response to fragmentation. Protect areas of suitable habitat and safeguard against logging and other threats.
Text account compilers
Berryman, A.
Contributors
Benstead, P., Gilroy, J. & Taylor, J.
Recommended citation
BirdLife International (2024) Species factsheet: Hose's Broadbill Calyptomena hosii. Downloaded from
https://datazone.birdlife.org/species/factsheet/hoses-broadbill-calyptomena-hosii 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.