• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

Taxonomic note
Turdus olivaceus, T. abyssinicus, T. roehli and T. smithi (del Hoyo and Collar 2016) were previously lumped as T. olivaceus following Collar and Stuart (1985) and Collar et al. (1994).

Taxonomic source(s)
Bowie, R.C. K.; Voelker, G.; Fjeldså, J.; Lens, L.; Hackett, S.J.; Crowe, T.M. 2005. Systematics of the Olive Thrush Turdus olivaceous species complex with reference to the taxonomic status of the endangered Taita Thrush T. helleri. Journal of Avian Biology 36: 391-404.
Bowie, R.C. K.; Voelker, G.; Fjeldså, J.; Lens, L.; Hackett, S.J.; Crowe, T.M. 2005. Systematics of the Olive Thrush Turdus olivaceous species complex with reference to the taxonomic status of the endangered Taita Thrush T. helleri. Journal of Avian Biology 36: 391-404.
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.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2016	Near Threatened	B1b(ii)
2012	Not Recognised
2008	Not Recognised
2006	Not Recognised
2004	Not Recognised
2000	Not Recognised
1994	Not Recognised
1988	Not Recognised

Migratory status	altitudinal migrant	Forest dependency	medium
Land-mass type		Average mass	73 g

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	4,700 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	unknown	-	-	-
Population trend	decreasing	-	inferred	-
Generation length	5.4 years	-	-	-
Number of subpopulations	2-100	-	-	-

Population justification: The global population size has not been quantified, but the species has been described as generally common and sometimes abundant, when still lumped with T. olivaceus (del Hoyo et al. 2005).

Trend justification: The species preferentially uses primary forest and only slightly disturbed forest (Newmark et al. 2010), which is likely to be declining as a result of encroachment of subsistence agriculture and wood extraction (e.g. Goodman et al. 1995). Negative population growth rates have also been reported for this species in some parts of its range (Newmark, 2006) and so the global population trend is thought to be declining.

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

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	suitable	resident
Forest	Subtropical/Tropical Moist Montane	major	resident
Altitude		Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Small-holder farming	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion

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Recommended citation
BirdLife International (2024) Species factsheet: Usambara Thrush Turdus roehli. Downloaded from https://datazone.birdlife.org/species/factsheet/usambara-thrush-turdus-roehli on 26/12/2024.
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 26/12/2024.