Justification of Red List category
Although this species may have a restricted range, it is not believed to approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <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 (<10,000 mature individuals with a continuing decline estimated to be >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 (>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 is described as common in suitable habitat (del Hoyo et al. 2005).
Trend justification
The population is suspected to be declining owing to on-going habitat loss and degradation (del Hoyo et al. 2005). Deforestation rates have been low over the past three generations (13.11 years), amounting to 2% (Global Forest Watch 2021, using Hansen et al. [2013] data and methods disclosed therein). The species tolerates secondary habitat so forest loss alone is unlikely to drive major declines. Population declines are therefore suspected to not exceed 10% over three generations.
Phyllastrephus poliocephalus is restricted to the montane forests of eastern Nigeria and western Cameroon, where it was discovered on the southern slopes of Mt Manenguba in the 1990s (Dowsett-Lemaire and Dowsett 1999), but is not found in the Bamenda Highlands (Stuart 1986) (earlier records from Mt Oku are now known to be in error [Dowsett-Lemaire and Dowsett 1998]). It is common to very common in suitable habitat, especially on Nlonako, Bakossi, and Kupe (P. Hall in litt. 1999, Dowsett-Lemaire and Dowsett 2000).
It inhabits tall, mature rainforest at intermediate elevations (Stuart 1986), and also occurs in secondary forest and secondary growth but always near primary forest (Rodewald et al. 1994). It is found at 500-1,800 m, rarely to 2,000 m, being most abundant at 1,200-1,800 m on Mt Kupe (del Hoyo et al. 2005). It feeds on insects, and forages mainly in the middle-strata and canopy, periodically descending to 3-4 m. Observations from Cameroon suggest that breeding takes place in November-April (del Hoyo et al. 2005).
Forest within the species' range is threatened by unsustainable exploitation for timber and firewood, uncontrolled burning and encroachment for agriculture (Stattersfield et al. 1998). The montane and semi-montane forests of western Cameroon are under increasing pressure for conversion to gardens and, especially in recent years, for establishing vast oil palm plantations, which have encroached upon some of the Bakossi block of forest, for example (F. Dowsett-Lemaire in litt. 2013).
Conservation Actions Underway
It occurs in Banyang-Mbo Wildlife Sanctuary and Rumpi Hills Forest Reserve in Cameroon (del Hoyo et al. 2005).
Text account compilers
Rotton, H.
Contributors
Dowsett, R.J., Dowsett-Lemaire, F., Hall, P., O'Brien, A., Robertson, P., Symes, A., Taylor, J. & Westrip, J.R.S.
Recommended citation
BirdLife International (2024) Species factsheet: Grey-headed Greenbul Phyllastrephus poliocephalus. Downloaded from
https://datazone.birdlife.org/species/factsheet/grey-headed-greenbul-phyllastrephus-poliocephalus 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.