LC
Sumatran Drongo Dicrurus sumatranus



Taxonomy

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.

IUCN Red List criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - -

Red List history
Year Category Criteria
2023 Least Concern
2016 Near Threatened A2c+3c+4c
2012 Near Threatened A2c+3c+4c
2008 Near Threatened A2c; A3c; A4c
2004 Near Threatened
2000 Lower Risk/Near Threatened
1994 Lower Risk/Near Threatened
1988 Lower Risk/Least Concern
Species attributes

Migratory status not a migrant Forest dependency high
Land-mass type shelf island
Average mass -
Range

Estimate Data quality
Extent of Occurrence (breeding/resident) 350,000 km2 medium
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size unknown - - -
Population trend decreasing poor suspected 2016-2027
Rate of change over the past 10 years/3 generations (longer of the two periods) 1-9% - - -
Rate of change over the future 10 years/3 generations (longer of the two periods) 1-9% - - -
Rate of change over the past & future 10 years/3 generations (longer of the two periods) 1-9% - - -
Generation length 3.55 years - - -
Number of subpopulations 2-4 - - -
Percentage of mature individuals in largest subpopulation 1-89% - - -

Population justification: The population size of this species has not been quantified, although it is described as fairly common (B. Harris in litt. 2016, Eaton et al. 2021). The total area of suitable habitat, spanning more than 40,000 km2, is large, and eBird (2022) data suggest the species does not occur at a particularly low density. Consequently, the population size is likely to be much larger than 10,000 mature individuals.

Trend justification: The population is suspected to be declining slowly due to habitat loss at the lower elevations of its range. In the three generations (10.7 years; Bird et al. 2020) to 2022, forest cover loss in its range was 2-4% (Global Forest Watch 2022, based on Hansen et al. [2013] and methods disclosed therein), and this is thought to have had an equivalent (hence minimal) impact on the population. Trapping for the songbird trade has also been identified as a threat to this species. However, the species has only very rarely (and in small numbers) appeared on physical market survey inventories (Chng et al. 2016, 2018), and using a web-scraping tool to mine data from online marketplace platforms, Okarda et al. (2022) found no D. sumatranus among c.105,000 listings, although they did detected 162 "Dicrurus sp.", at least some of which may refer to this species. Consequently, although trapping may cause local losses at the most accessible locations, it is unlikely to be causing significant reductions in global population size. Evaluating all the data available, the population is suspected of declining at a past and future rate of 1-9% over three generations. With much of the range lying in protected areas, there is little prospect of the rate of declining substantially worsening in the near-future.


Country/territory distribution
Country/Territory Presence Origin Resident Breeding visitor Non-breeding visitor Passage migrant
Indonesia extant native yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Indonesia Bukit Bahar - Tajau Pecah
Indonesia Bukit Barisan Selatan
Indonesia Bukit Kaba
Indonesia Gunung Dempo
Indonesia Gunung Leuser
Indonesia Kerinci Seblat
Indonesia Meranti
Indonesia Pulau Siberut
Indonesia Siak Kecil

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Lowland suitable resident
Forest Subtropical/Tropical Moist Montane major resident
Altitude 0 - 1600 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Agro-industry farming Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture Annual & perennial non-timber crops - Small-holder farming Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture Wood & pulp plantations - Agro-industry plantations Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Stresses
Species mortality
Biological resource use Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation, Ecosystem conversion

Utilisation
Purpose Scale
Pets/display animals, horticulture national

Recommended citation
BirdLife International (2024) Species factsheet: Sumatran Drongo Dicrurus sumatranus. Downloaded from https://datazone.birdlife.org/species/factsheet/sumatran-drongo-dicrurus-sumatranus 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.