VU
Thyolo Alethe Chamaetylas choloensis



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.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - B2ab(i,ii,iii,iv,v)

Red List history
Year Category Criteria
2018 Vulnerable B2ab(i,ii,iii,iv,v)
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) 49,600 medium
Extent of Occurrence breeding/resident (km2) 1,360
Number of locations 16 -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 2500-9999 medium suspected 2005
Population trend Decreasing medium inferred -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) - - -
Decline (10 years/3 generation past and future) - - -
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 mature individuals (1,000-1,500 pairs [Spottiswoode et al. 2008, Dowsett-Lemaire and Dowsett 2009, Bayliss et al. 2014]), 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 overall population is placed in the range bracket 2,500-9,999 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. However, deforestation analysis by Tracewski et al. (2016) estimated an annual decline in forest cover within this species’s range to be c.0.2% between 2000 and 2012, which would roughly equate to a decline of 4.5% over three generations (c.20 years). 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. Therefore, the overall rate of decline is uncertain.


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 Namizimu Forest Reserve
Malawi Mangochi Mountain Forest Reserve
Malawi Liwonde Hills Forest Reserve
Malawi Soche Mountain Forest Reserve
Malawi Mount Mulanje Forest Reserve
Malawi Thyolo Mountain Forest Reserve
Mozambique Mount Namuli
Mozambique Mount Chiperone
Mozambique Njesi plateau
Mozambique Mount Mabu

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 - Agro-industry farming Timing Scope Severity Impact
Past, Likely to Return Minority (<50%) Slow, Significant Declines Past Impact
Stresses
Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture Annual & perennial non-timber crops - Small-holder farming Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
Stresses
Ecosystem degradation, Ecosystem conversion
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
Human intrusions & disturbance Work & other activities Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Natural system modifications Fire & fire suppression - Trend Unknown/Unrecorded Timing Scope Severity Impact
Past, Likely to Return Minority (<50%) Slow, Significant Declines Past Impact
Stresses
Ecosystem degradation, Ecosystem conversion
Residential & commercial development Housing & urban areas Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Transportation & service corridors Roads & railroads Timing Scope Severity Impact
Future Minority (<50%) Slow, Significant Declines Low Impact: 4
Stresses
Ecosystem degradation, Ecosystem conversion

Recommended citation
BirdLife International (2020) Species factsheet: Chamaetylas choloensis. Downloaded from http://www.birdlife.org on 05/08/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 05/08/2020.