Justification of Red List Category
This species is suspected to be in decline owing to habitat loss and degradation throughout its range. It is apparently tolerant of secondary and logged forests, suggesting that rates of decline are only likely to be moderately rapid. It is therefore currently considered Near Threatened, but may be eligible for downlisting if there is evidence that declines are less severe than previously considered.
The population size of this species has not been quantified, but it is described as fairly common at relatively high elevations (B. Harris in litt. 2016).
Data on trends are lacking, but continuing habitat loss within the species's range suggests that a moderately rapid population decline is likely to be occurring.
Dicrurus sumatranus is restricted to Sumatra (with race viridinitens on the Mentawai Islands), Indonesia (BirdLife International 2001). It is fairly widespread, and has been described as a relatively common member of mixed species foraging parties in mid-elevation forests.
This species occurs in lowland, hill and lower montane forest and tall secondary forest up to 1,700 m (Harris et al. 2017). It has been recorded (rarely) in Way Kambas National Park (highest point 16 m), but appears to be more common at mid altitudes. It regularly joins mixed species foraging parties.
The loss of lowland forest in Sumatra has been extensive as a result of both regulated and illegal logging, as well as conversion to agriculture.
Conservation Actions Underway
No targeted conservation actions are known for this species.
Conservation Actions Proposed
Conduct repeated surveys within the species's range to determine current distribution and abundance, as well as assess population trends and rates of habitat loss. 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 agricultural encroachment.
Text account compilers
Martin, R, Gilroy, J., Benstead, P., Taylor, J.
BirdLife International (2020) Species factsheet: Dicrurus sumatranus. Downloaded from http://www.birdlife.org on 21/09/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 21/09/2020.