Data Zone
Justification of Red List category
This species has a relatively 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 ten years or three generations). The population size is not quantified but is not thought 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 estimated. It has a large range throughout the central highlands of Borneo, although it is typically described as local or rare (Mann 2008, Eaton et al. 2016).
Trend justification
There are no accurate trend data available for this species, although it is suspected of declining. Forest loss in this species' mapped range has been equivalent to c.3-4% over the past ten years (Global Forest Watch 2022, using data from Hansen et al. [2013] and methods disclosed therein). This species is thought to be moderately forest dependent and is likely to be declining at a rate broadly similar to that of forest loss.
The species is endemic to the highlands of Borneo, where it is recorded from Sabah and Sarawak, Malaysia, Brunei Darussalam, and Kalimantan, Indonesia.
It inhabits submontane forest, favouring undergrowth and the shaded lower storey; at 400-1,400 m (Eaton et al. 2021).
The principal threat to this species is forest loss. Its preference for submontane forest, however, buffers it from the worst impacts of Sundaic lowland forest loss and currently it is thought to be losing habitat at a rate of only c.3-4% every ten years (Global Forest Watch 2022, based on Hansen et al. 2013).
Conservation Actions Underway
None is known, although the species occurs in numerous protected areas.
Conservation Actions Proposed
Continue to monitor forest cover in its range using remote sensing data.
Text account compilers
Berryman, A.
Recommended citation
BirdLife International (2025) Species factsheet: Dayak Blue Flycatcher Cyornis montanus. Downloaded from
https://datazone.birdlife.org/species/factsheet/dayak-blue-flycatcher-cyornis-montanus on 05/01/2025.
Recommended citation for factsheets for more than one species: BirdLife International (2025) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 05/01/2025.