LC
Crossley's Ground-thrush Geokichla crossleyi



Justification

Justification of Red List category
This species has an extremely large range, and hence does not 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 rare to locally fairly common (del Hoyo et al. 2005).

Trend justification
The population is inferred to be declining owing to ongoing habitat loss and fragmentation. The likely rate of decline however is suspected to be <20% over three generations (Global Forest Watch 2020).

Distribution and population

Geokichla crossleyi is found in south-eastern Nigeria (on the Obudu and Mambilla Plateaux and Gotel Mountains), Cameroon (from Mt Cameroon and the Rumpi Hills in the south-west to Mt Tchabal Mbabo on the Adamawa Plateau [Dowsett-Lemaire and Dowsett 1999]), south-western Congo and north-eastern Democratic Republic of Congo (DRC) (Urban et al. 1997). In Nigeria, it was found to be common at Chappal Waddi in the Gotel Mountains but less numerous elsewhere in 1988 (Ash et al. 1989). In Cameroon, it was quite common to very common in the northern Bakossi Mountains in 1998 and on Mt Nlonako in 1999 (Dowsett-Lemaire and Dowsett 1998, 1999), and was also discovered on the southern slopes of Mt Manenguba in 1999 (Dowsett-Lemaire and Dowsett 1999) and seen again there in 2000 (Dowsett-Lemaire and Dowsett 2000).

Ecology

It inhabits mid-altitude forest, at 1,000-2,300 in Cameroon, 500-600 m in Congo and 960-1,850 m in DRC (del Hoyo et al. 2005), preferring wetter parts of primary forest, particularly ravines (Urban et al. 1997). It feeds mainly on insects and also takes seeds, foraging on the ground in deep cover (del Hoyo et al. 2005). Breeding probably occurs during the rainy season. In Cameroon, the species may undertake altitudinal migrations, but the extent of this is unknown (del Hoyo et al. 2005).

Threats

The species is susceptible to forest loss within its increasingly fragmented range. In DRC, the species's habitat is being encroached by banana plantations (del Hoyo et al. 2005). The montane and semi-montane forests of western Cameroon are under increasing pressure from clearance for gardens (e.g. Mt Kupe) and, in recent years, for the expansion of large-scale oil-palm plantations, which has led to the encroachment of the Bakossi block of forest (F. Dowsett-Lemaire in litt. 2013).

Conservation actions

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

Conservation Actions Proposed
Carry out surveys to assess the total population size. Monitor population trends through regular surveys. Monitor rates of habitat loss and degradation. Protect suitable habitat for the species.

Acknowledgements

Text account compilers
Clark, J.

Contributors
Dowsett-Lemaire, F., O'Brien, A., Rainey, H., Robertson, P., Symes, A., Taylor, J. & Westrip, J.R.S.


Recommended citation
BirdLife International (2024) Species factsheet: Crossley's Ground-thrush Geokichla crossleyi. Downloaded from https://datazone.birdlife.org/species/factsheet/crossleys-ground-thrush-geokichla-crossleyi 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.