Justification of Red List category
This species has a large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence under 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 size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (under 10,000 mature individuals with a continuing decline estimated to be over 10% in ten years or three generations, or with a specified population structure). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (over 30% decline over ten years or three generations). For these reasons the species is evaluated as Least Concern.
Population justification
The global population size has not been quantified, but the species prior to its split from P. icterinus was described as generally common to abundant (del Hoyo et al. 2005), and it is found in several subpopulations. This species is considered to have a medium dependency on forest habitat, and tree cover is estimated to have declined by 10.5% within its mapped range over the past 10 years (Global Forest Watch 2022, using Hansen et al. [2013] data and methods disclosed therein). Therefore, as a precautionary measure, it is tentatively suspected that this loss of cover may have led to a decline of between 1-19% in the species' population size over the same time frame.
Trend justification
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P. lorenzi is apparently scarce, and is restricted to the eastern lowlands of Democratic Republic of Congo (DRC) and also at Ntandi in Semliki Forest in Uganda (Keith et al. 1992). In the DRC, there is a somewhat isolated record from Bambesa as well as populations in the Semliki/Ituri Forests and from the lowland parts of the Itombwe Mountains (Stattersfield et al. 1998).
It is a species of lowland and transitional forest at altitudes of 600-1,580 m (Fishpool and Tobias 2016).
Forest habitats occupied by the species are threatened by clearance for shifting cultivation and degradation through the removal of understorey tree species to create cacao plantations (Howard 1991).
Text account compilers
Rutherford, C.A.
Recommended citation
BirdLife International (2024) Species factsheet: Sassi's Olive Greenbul Phyllastrephus lorenzi. Downloaded from
https://datazone.birdlife.org/species/factsheet/sassis-olive-greenbul-phyllastrephus-lorenzi on 23/12/2024.
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 23/12/2024.