Turdus olivaceofuscus 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Passeriformes Turdidae

Scientific Name: Turdus olivaceofuscus Hartlaub, 1852
Common Name(s):
English Sao Tome Thrush, Olivaceous Thrush, São Tomé Thrush
French Grive de São Tomé
Taxonomic Source(s): Melo, M.; Bowie, R. C. K.; Voelker, G.; Dallimer, M.; Collar, N. J.; Jones, P. J. 2010. Multiple lines of evidence support the recognition of a very rare bird species: the Principe Thrush. Journal of Zoology (London) 282(2): 120-129.
Identification information: 24 cm. Dull olive-brown above from head below eye to tail; head slightly darker. Chin and throat dusky buff with whitish streaks. Dusky buff scales on buff-washed breast, shading to dusky-buff scalloping on whitish remaining underparts. Underwing coverts pale orange-buff against creamy secondaries. Iris brown to red. Bill large and dark with lighter yellowish tip. Legs dark brownish-grey. Sexes similar. Juvenile like adult with light buff flecking above and blotched brown below. Similar spp. T. xanthorhynchus on Príncipe is darker with coarser scaling on the underparts and yellow bill and legs.

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2016
Date Assessed: 2016-10-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Atkinson, P., Faustino de Lima, R., Gascoigne, A. & d'Assis Lima, S.
Facilitator/Compiler(s): Khwaja, N., O'Brien, A., Peet, N., Robertson, P., Starkey, M., Taylor, J. & Westrip, J.
This species has a very small range, in which the area and quality of optimal habitats are in decline, and is thought to have a small population, which is suspected to be in decline owing to habitat loss and degradation, persecution and predation. However, it does not qualify as threatened because its population is not severely fragmented or restricted to 10 locations or less, and there are insufficient data available on its population size and subpopulation structure. For these reasons the species is listed as Near Threatened.

Previously published Red List assessments:

Geographic Range [top]

Range Description:Turdus olivaceofuscus is endemic to São Tomé, São Tomé e Príncipe. It is widely distributed at low densities (Atkinson et al. 1991, Christy and Clarke 1998), being found in most habitats with tree cover (Dallimer et al. 2010) and, although its population size has not been estimated, it is thought to number more than 2,500 individuals (R. Faustino de Lima in litt. 2010).

Countries occurrence:
Sao Tomé and Principe (Sâo Tomé)
Additional data:
Continuing decline in area of occupancy (AOO):Yes
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:930
Continuing decline in extent of occurrence (EOO):UnknownExtreme fluctuations in extent of occurrence (EOO):No
Number of Locations:11-100Continuing decline in number of locations:Unknown
Extreme fluctuations in the number of locations:No
Upper elevation limit (metres):2024
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:The species's population size has not been estimated, but it is thought to number more than 2,500 individuals (R. Faustino de Lima in litt. 2010).

Trend Justification:  The species's population is suspected to be experiencing a continuing decline owing to habitat loss and degradation coupled with predation by introduced species and persecution by humans (del Hoyo et al. 2005, R. Faustino de Lima in litt. 2010).

Current Population Trend:Decreasing
Additional data:
Number of mature individuals:2500-9999Continuing decline of mature individuals:Yes
Extreme fluctuations:NoPopulation severely fragmented:No
Continuing decline in subpopulations:Unknown
Extreme fluctuations in subpopulations:NoAll individuals in one subpopulation:No

Habitat and Ecology [top]

Habitat and Ecology:The species inhabits primary and secondary forest up to 2,024 m (Atkinson et al. 1991, Christy and Clarke 1998). It prefers lowland habitats, and also occupies cocoa plantations with Erythrina shade trees, orchards, gardens and coffee plantations, as well as dry woodland in savanna and cloudforest (del Hoyo et al. 2005, Dallimer et al. 2010). However, it is far less abundant in plantations compared to forest (de Lima et al. 2014) It feeds on invertebrates and fruit. Breeding takes place from the end of July until January, with a peak between October and December. The nest, in which two eggs are laid, is a bulky cup of mixed dry plant matter and mud, usually situated 0.5-4 m above the ground in dense vegetation (del Hoyo et al. 2005).

Continuing decline in area, extent and/or quality of habitat:Yes
Generation Length (years):6.1
Movement patterns:Not a Migrant

Threats [top]

Major Threat(s): The area of remaining primary forest is small and could be vulnerable to destruction and degradation in the future. On-going changes in land use are driven largely by a growing human population and foreign investment in agricultural projects such as the expansion of oil palm cultivation (R. Faustino de Lima in litt. 2010). Land privatisation is leading to an increase in the number of small farms and the clearance of trees. The removal of shade trees in cocoa plantations is a local threat (del Hoyo et al. 2005). Road developments along the east and west coasts of São Tomé are increasing access to previously remote areas (A. Gascoigne in litt. 2000). As such, habitat loss and degradation are becoming increasingly serious threats (R. Faustino de Lima in litt. 2010). Many nests are destroyed by brown rats Rattus norvegicus (del Hoyo et al. 2005). It also suffers an unquantified level of mortality through persecution by children who commonly target the species with slingshots (R. Faustino de Lima in litt. 2010).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
No targeted conservation action is known for this species.

Conservation Actions Proposed
Carry out surveys to obtain a total population estimate. Monitor population trends through regular surveys. Monitor the clearance and degradation of favoured habitats. Quantify the impact of nest predation by rats. Carry out control measures against rats. Protect tracts of forest occupied by the species.

Citation: BirdLife International. 2016. Turdus olivaceofuscus. The IUCN Red List of Threatened Species 2016: e.T22736406A95133056. . Downloaded on 22 September 2018.
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