Hill Blue-flycatcher Cyornis banyumas


Justification of Red List Category
This species has an extremely 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 has not been quantified, but it is not believed 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 is unknown, but the species is described as common or locally common throughout much of South-East Asia, very common in Thailand and Peninsular Malaysia and common in Borneo and Sumatra (del Hoyo et al. 2006).

Trend justification
A remote sensing study found that forest within its range is lost at a rate of 3% over three generations (Tracewski et al. 2016). The species is moreover moderately targeted for the cagebird trade; subspecies banyumas on Java is now reported on the markets in large numbers, but rarely recorded in the wild (D. Jeggo in litt. 2018). Therefore, the species is assumed to be undergoing a slow decline of <10%.


Text account compilers
Hermes, C., Calvert, R.

Jeggo, D.

Recommended citation
BirdLife International (2021) Species factsheet: Cyornis banyumas. Downloaded from on 08/03/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from on 08/03/2021.