Data Zone
Justification of Red List category
This species is suspected to be declining moderately fast because of forest loss in its non-breeding areas on the Thai-Malay Peninsula. For this reason it is assessed as Near Threatened.
Population justification
The population size is unknown but the species is described as rare in north-east India, but rather common in northern Myanmar where one study (Rasmussen et al. 2011) found it to be among the commonest passerines mist-netted.
Trend justification
Although this species appears tolerant of degraded habitats on passage, all wintering records have been in primary and selectively logged mature secondary forest with a well-developed understorey on the Thai-Malay Peninsula (Sa-ar et al. 2021). Global Forest Watch data indicate that forest cover loss within the wintering range of the species was 14-16% over the past 10 years (Global Forest Watch [2021] using data from Hansen et al. [2013] and methods disclosed therein). This accelerated after 2016, when the rate averaged 1.9-2.1% per annum over the past five years, equivalent to 19-21% over 10 years. Given this species' apparent dependence on this habitat, it is suspected to be declining at a near-equal rate to forest loss. There is no reason to suppose that rates of forest loss in this region are going to slow over the next decade, and they may be accelerating. Consequently, over the next 10 years, the species is suspected to decline by 20-25%.
Breeds in the east Himalaya, in Nepal, Bhutan, north-east India, and northern Myanmar (Renner et al. 2009). Birds winter on the Thai-Malay Peninsula, principally in Thailand and Tenasserim, Myanmar, but with records also in Peninsular Malaysia, albeit none post-1960 (J. Eaton in litt. 2021). Assessment of this species's distribution is hampered by its former taxonomic treatment as a subspecies of C. banyumas, and the identification difficulties posed.
Breeds in hill evergreen forest. At 750–1,800 m (mainly above 1,200 m, but recorded also at 300 m in summer) in north Assam and to 1900 m in Arunachal Pradesh, and presumably at similar elevations in Sikkim; c.550–900 m in northern Myanmar (del Hoyo et al. 2020). On migration, occurs in a wide range of habitats, including wooded parks and gardens, but when wintering appears to be confined to primary and mature selectively logged forest from sea-level to c.600 m (Sa-ar et al. 2021).
The principal threat to this species is lowland forest loss in its wintering range on the Thai-Malay Peninsula (Global Forest Watch 2021, using data from Hansen et al. [2013] and methods disclosed therein).
Conservation and Research Actions Underway
Occurs in numerous protected areas in both breeding and non-breeding areas.
Conservation and Research Actions Proposed
Continue to monitor forest loss using remote sensing data, especially on its wintering grounds on the Thai-Malay Peninsula. Undertake survey effort to confirm whether the current assumption of it having a small wintering range is correct, or whether it occurs more widely on the Peninsula, or even on Sumatra. Use this information, and surveys of its breeding grounds, to generate a population estimate. Establish whether forest loss is the only threat to this species or whether, like other Cyornis, it is also affected by trade. Protect areas of lowland forest in its wintering grounds.
Text account compilers
Berryman, A., Calvert, R., Vine, J.
Contributors
Eaton, J.
Recommended citation
BirdLife International (2024) Species factsheet: Large Blue Flycatcher Cyornis magnirostris. Downloaded from
https://datazone.birdlife.org/species/factsheet/large-blue-flycatcher-cyornis-magnirostris on 22/12/2024.
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 22/12/2024.