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Dicrurus adsimilis 

Scope:Global
Status_ne_offStatus_dd_offStatus_lc_onStatus_nt_offStatus_vu_offStatus_en_offStatus_cr_offStatus_ew_offStatus_ex_off

Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Passeriformes Dicruridae

Scientific Name: Dicrurus adsimilis
Species Authority: (Bechstein, 1794)
Common Name(s):
English Fork-tailed Drongo
French Drongo brillant
Taxonomic Notes: Dicrurus modestus (Sibley and Monroe 1990, 1993), including the subspecies coracinus from west and central Africa, and the subspecies modestus confined to the island of Príncipe and D. adsimilis (Sibley and Monroe 1990, 1993) were previously treated as D. modestus (a monotypic species confined to Príncipe only) and D. adsimilis (including coracinus) following Collar and Andrew (1988). All are now lumped into D. adsimilis following Dowsett and Forbes-Watson (1993), for a review by the BirdLife Taxonomic Working Group found no precedent or justification in the primary literature for treating modestus as distinct. Adult specimens in the Natural History Museum, Tring are essentially as on the mainland.

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2012
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Facilitator/Compiler(s): Temple, H.
Justification:
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). The population trend appears to be stable, and hence the species does not 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.
Previously published Red List assessments:
2009 Least Concern (LC)
2008 Least Concern (LC)
2006 Least Concern (LC)
2004 Not Recognized (NR)
2000 Not Recognized (NR)
1994 Not Recognized (NR)
1988 Not Recognized (NR)

Geographic Range [top]

Range Description: The subspecies modestus (previously recognised as a separate species), is endemic to the island of Príncipe, São Tomé e Príncipe. Increased use of pesticides would reduce the abundance of its invertebrate prey and might lead to its disappearance from cultivated areas. The number of small farms on Príncipe is increasing as land is privatised, which is in turn leading to a reduction in tree cover. It is not known how this will affect the subspecies.
Countries occurrence:
Native:
Angola (Angola); Benin; Botswana; Burkina Faso; Burundi; Cameroon; Central African Republic; Chad; Congo; Congo, The Democratic Republic of the; Côte d'Ivoire; Djibouti; Equatorial Guinea; Eritrea; Ethiopia; Gabon; Gambia; Ghana; Guinea; Guinea-Bissau; Kenya; Lesotho; Liberia; Malawi; Mali; Mauritania; Mozambique; Namibia; Niger; Nigeria; Rwanda; Sao Tomé and Principe; Senegal; Sierra Leone; Somalia; South Africa; South Sudan; Sudan; Swaziland; Tanzania, United Republic of; Togo; Uganda; Zambia; Zimbabwe
Present - origin uncertain:
Yemen
Continuing decline in area of occupancy (AOO): Unknown
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 14400000
Continuing decline in extent of occurrence (EOO): Unknown
Extreme fluctuations in extent of occurrence (EOO): No
Continuing decline in number of locations: Unknown
Extreme fluctuations in the number of locations: No
Upper elevation limit (metres): 2200
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: The global population size has not been quantified, but it is believed to be large as the species is described as common in at least parts of its range (Hall and Moreau 1970, Roberts 1993, Zimmerman et al. 1996, Borrow and Demey 2001, Stevenson and Fanshawe 2002). The subspecies modestus (previously recognised as a separate species), was considered Near Threatened, although its population size is unknown numbers are assumed to be small.

Trend Justification:  The population is suspected to be stable in the absence of evidence for any declines or substantial threats.
Current Population Trend: Stable
Additional data:
Continuing decline of mature individuals: Unknown
Extreme fluctuations: No Population severely fragmented: No
Continuing decline in subpopulations: Unknown
Extreme fluctuations in subpopulations: No All individuals in one subpopulation: No

Habitat and Ecology [top]

Habitat and Ecology: Subspecies modestus is widespread in open and forested habitats, with the exception of primary forest on the central massif, and is commonest in open plantations and in edge habitats (Atkinson et al. 1991, J. Baillie and A. Gascoigne in litt. 2000).
Systems: Terrestrial
Continuing decline in area, extent and/or quality of habitat: Unknown
Generation Length (years): 2.8
Movement patterns: Not a Migrant

Threats [top]

Major Threat(s): The subspecies modestus could be adversely affected by an increase in the use of pesticides, which would reduce the abundance of its invertebrate prey and might lead to its disappearance from cultivated areas. The number of small farms on Príncipe is increasing as land is privatised, which is in turn leading to a reduction in tree cover. It is not known how this will affect the subspecies.

Citation: BirdLife International. 2012. Dicrurus adsimilis. The IUCN Red List of Threatened Species 2012: e.T22731506A39793077. . Downloaded on 09 February 2016.
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