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Thyolo Alethe Chamaetylas choloensis
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Taxonomy

Taxonomic note
Chamaetylas choloensis (del Hoyo and Collar 2016) was previously listed as Pseudalethe choloensis.

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.
Dowsett, R. J.; Forbes-Watson, A. D. 1993. Checklist of birds of the Afrotropical and Malagasy regions. Tauraco Press, Li
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- B1ab(i,ii,iii,iv,v) A2c+3c+4c; B1ab(i,ii,iii,iv,v)

Red List history
Year Category Criteria
2016 Endangered B1ab(i,ii,iii,iv,v)
2013 Endangered B1ab(i,ii,iii,iv,v)
2012 Endangered B1ab(i,ii,iii,iv,v)
2008 Endangered A2c; A3c; A4c; B1a+b(i,ii,iii,iv,v)
2004 Endangered
2000 Endangered
1996 Vulnerable
1994 Vulnerable
1988 Threatened
Species attributes

Migratory status not a migrant Forest dependency Medium
Land mass type Land-mass type - continent
Average mass -
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 4,700 medium
Number of locations 16 -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 1500-7000 medium suspected 2005
Population trend Decreasing medium suspected -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) 30-49 - - -
Decline (10 years/3 generation past and future) 30-49 - - -
Number of subpopulations 2-100 - - -
Largest subpopulations - - -
Generation length (yrs) 6.5 - - -

Population justification: The world population was thought to be in the range of c.2,500-5,000 mature individuals, however in 2005 the species was discovered on Mt Mabu in Mozambique, where the population is conservatively suspected to number c.2000 individuals, and there are other areas of this country that could hold the species. Thus on the basis that further exploration is required before a reliable estimate of the total population can be made, the population is placed in the range bracket for 2,500-9,999 individuals. This equates to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals.

Trend justification: The population is suspected to be declining very rapidly in Malawi in line with the extensive clearance and degradation of highland forests there, and to a lesser degree in Mozambique, with a substantial proportion of the known population occurring on Mt Mabu where there is currently relatively low pressure on the forest. Overall, the rate of decline over 20 years (three generations) is suspected to have been rapid. Further substantial populations may occur in intact forests in unsurveyed areas of Mozambique (Spottiswoode et al. 2008), which, if found to be the case, would have a bearing on the overall proportion of the population that is decreasing and thus the overall rate of decline.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Malawi N Extant Yes
Mozambique N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Malawi Liwonde Hills Forest Reserve
Malawi Mangochi Mountain Forest Reserve
Malawi Mount Mulanje Forest Reserve
Malawi Namizimu Forest Reserve
Malawi Soche Mountain Forest Reserve
Mozambique Mount Chiperone
Mozambique Mount Mabu
Mozambique Mount Namuli
Mozambique Njesi plateau

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Dry suitable resident
Forest Subtropical/Tropical Moist Lowland suitable resident
Forest Subtropical/Tropical Moist Montane suitable resident
Savanna Dry suitable resident
Altitude 700 - 1700 m Occasional altitudinal limits 720 - 1900 m

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops Timing Scope Severity Impact
Past, Likely to Return Minority (<50%) Slow, Significant Declines
Stresses
Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture Annual & perennial non-timber crops Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Logging & wood harvesting Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines
Stresses
Ecosystem degradation
Human intrusions & disturbance Work & other activities Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines
Stresses
Ecosystem degradation, Ecosystem conversion
Natural system modifications Fire & fire suppression Timing Scope Severity Impact
Past, Likely to Return Minority (<50%) Slow, Significant Declines
Stresses
Ecosystem degradation, Ecosystem conversion
Residential & commercial development Housing & urban areas Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines
Stresses
Ecosystem degradation, Ecosystem conversion
Transportation & service corridors Roads & railroads Timing Scope Severity Impact
Future Minority (<50%) Slow, Significant Declines
Stresses
Ecosystem degradation, Ecosystem conversion

Recommended citation
BirdLife International (2017) Species factsheet: Chamaetylas choloensis. Downloaded from http://www.birdlife.org on 19/10/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 19/10/2017.