This species now has a highly fragmented distribution; the majority of breeding colonies are extremely small and isolated, and many are close to the minimum for long-term viability. Forest throughout its range is disappearing rapidly, leading to further fragmentation and rapid decline of remaining populations. It is therefore classified as Vulnerable. Its long-term future will depend on the continued existence and proper management of the forest reserves and other protected areas in which it occurs.
Taxonomic source(s)
Dowsett, R. J.; Forbes-Watson, A. D. 1993. Checklist of birds of the Afrotropical and Malagasy regions. Tauraco Press, Li
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.
Identification
Large, unusual bird with brightly coloured, naked head. Bright, chrome-yellow and black head is diagnostic. Neck and underparts gleaming white with dark, bluish-grey upperparts and tail. Voice Breathy shhhissss and other soft tok calls, but usually silent.
Picathartes gymnocephalus is known from Guinea (six sites; population probably declining [Thompson et al. 2004]), Sierra Leone (18 sites), Liberia (six sites; population probably declining [Thompson et al. 2004]; most records in northern highlands [Gatter 1997]), Côte d'Ivoire (six sites; population likely to be declining [Thompson et al. 2004] as forest is being cleared and logged in areas which have not been surveyed [H. Rainey in litt. 2007]), and Ghana (many records into the 1960s, then none confirmed [H. S. Thompson in litt. 1999] until 2003 [Marks et al. 2004], and now known from seven sites; population has probably rapidly declined in last 30 years [Thompson et al. 2004, A. Asamoah in litt. 2012]). It was thought to be extinct in Ghana until one was trapped at Subim Forest Reserve (Anon. 2006) in the Brong-Ahafo Region. Follow-up surveys in the Subim and adjoining Ayum and Bonsam Bepo forest reserves located 13 active nests and two individuals (Anon. 2006). Further investigations have since located seven major nesting areas within the high forest zone (Asamoah 2011). In Sierra Leone, numbers are estimated at c.1,400, with populations in forest reserves close to the minimum for long-term viability, and surveys of the Western Area Peninsula Forest indicating a decline of 20% in the number of nests between 1997-2007 (Anon 2008). In Liberia, the minimum population is estimated at 1,000 pairs (Gatter 1997). The global population in the Upper Guinea forest is almost certainly far fewer than 10,000 mature individuals, and this is supported by estimates for range states provided by various sources (Thompson et al. 2004).
Population justification
The total population is estimated at fewer than 10,000 individuals. This figure is supported by estimates for range states provided by various sources. It is placed in the band 2,500-9,999 mature individuals, equating to 3,750-14,999 individuals, rounded here to 3,500-15,000 individuals.
Trend justification
The species's population is suspected to be declining rapidly, in line with forest clearance and degradation across its range.
Ecology
It is found in lowland primary and secondary forest, forest clearings, and gallery forest (Thompson 1997, 1998, L. D. C. Fishpool in litt. 1999) mainly in rocky, hilly terrain (up to 800 m on Mt Nimba) (Gatter 1997, Thompson 1998) but has survived at highly degraded sites (Salewski et al. 2000) and close to urban centres (Thompson and Fotso 2000), perhaps indicating a fairly high tolerance of disturbance (Thompson et al. 2004). The species is found in the proximity of flowing streams and rivers, where wet mud may be gathered for nest construction (Thompson et al. 2004). A study of the ecology and distribution of the species in Ghana indicated that it uses fresh earthworm mounds to construct its nest (Asamoah 2011). It is known from montane forests in Sierra Leone and Liberia (Thompson et al. 2004). It feeds mainly on invertebrates, usually singly and largely within one metre of the forest floor (Thompson and Fotso 1995). They frequently follow army ant columns (Thompson 1998) to capture flushed prey (Thompson et al. 2004). They take beetles, termites, ants and grasshoppers, as well as earthworms, spiders and vertebrates such as frogs and lizards (Thompson et al. 2004). There is some evidence that vertebrates in the diet during the breeding season may be fed largely to nestlings (Thompson 1997). It breeds in colonies of up to 40 pairs (although the majority consist of only 2-5, and many nests stand alone [Thompson 2004b]), on rock-faces, cliffs, cave roofs and walls and infrequently in large, fallen hollow trees (Thompson and Fotso 1995, Atkinson et al. 1996b, Gatter 1997, Thompson 1998); rocky sites are the most common, however. In lowland forest breeding follows rainfall and maybe be once or twice yearly as a result (Thompson and Fotso 2000). The species appears to be monogamous (Thompson et al. 2004). The nest is a cup-shaped mud construction in which dried leaves, fibres and twigs are embedded (Thompson 2004b). In Sierra Leone, egg-laying occurs from early June until late December, and chicks occupy nests from August to January (Thompson 2004a, b) Egg-laying in Ghana starts from early March and continues through to mid-December (Asamoah 2011). Clutch size is one or two and breeding success is low (Thompson 1997). In Sierra Leone, the most common clutch size was found to be two, with incubation lasting for 17-23 days and the fledging period lasting for 23-29 days (Thompson 2004b). Nest mortality was caused by predation and infanticide by other adults, and breeding success was only 0.44 chicks fledged per pair. Natural nest predators probably include cobras Naja species, monitor lizards Varanus niloticus, forest sun squirrels Heliosciurus, raptors and colobine monkeys Procolobus species. The low breeding success of the populations studied in Sierra Leone suggest that they are in decline, that is unless adult survival exceeds 90% and the species is very long-lived (Thompson 2004b).
Related state of the world's birds case studies
References
Collar, N. J.; Stuart, S. N. 1985. Threatened birds of Africa and related islands: the ICBP/IUCN Red Data Book. International Council for Bird Preservation, and International Union for Conservation of Nature and Natural Resources, Cambridge, U.K.
Atkinson, P.; Turner, P.-A.; Pocknell, S.; Broad, G.; Koroma, A. P.; Annaly, D.; Rowe, S. 1996. Landuse and conservation in the Mount Loma Reserve, Sierra Leone. Report of the University of East Anglia - BirdLife International expedition to the Mount Loma reserve in north-eastern Sierra Leone (January-April 1992).
Thompson, H. S.; Fotso, R. 1995. Rockfowl: the genus Picathartes. Bulletin of the African Bird Club 2(1): 25-28.
Gatter, W. 1997. Birds of Liberia. Pica Press, Robertsbridge, UK.
Holbech, L. H. 1996. Faunistic diversity and game production contra human activities in the Ghana high forest zone, with reference to the Western Region.
Thompson, H. S. 1998. White-necked Picathartes Picathartes gymnocephalus: its ecology and conservation. Royal Society for the Protection of Birds, Sandy, UK.
Thompson, H. S. 1997. The breeding biology and ecology of the White-necked Picathartes Picathartes gymnocephalus Temminck 1825, in Sierra Leone. Dissertation. Ph.D., Open University.
Salewski, V.; Göken, F.; Korb, J.; Schmidt, S. 2000. Has the White-necked Picathartes Picathartes gymnocephala still a chance in Lamto, Ivory Coast? Bird Conservation International 10: 41-46.
Thompson, H. S.; Fotso, R. 2000. Conservation of two threatened species: Picathartes. Ostrich 71(1 & 2): 154-156.
Marks, B. D.; Weckstein, J. D.; Johnson, K. P.; Meyer, M. J.; Braimah, J.; Oppong, J. 2004. Rediscovery of the White-necked Picathartes Picathartes gymnocephalus in Ghana. Bulletin of the British Ornithologists' Club 124: 151-153.
Thompson, H.S. 2004. The reproductive biology of the White-necked Picathartes Picathartes gymnocephalus. Ibis 146: 615-622.
Thompson, H.S. 2004. Behaviour of the White-necked Picathartes Picathartes gymnocephalus, at nest sites prior to breeding. Malimbus 26(1-2): 24-30.
Thompson, H.; Siaka, A.; Lebbie, A.; Evans, S. W.; Hoffmann, D.; Sande, E. 2004. International Action Plan for the White-necked Picathartes Picathartes gymnnocephalus. BirdLife International Africa Partnership Secretariat, Nairobi.
Anon. 2008. Communities unite to protect White-necked Picathartes. World Birdwatch 30(2): 7.
Anon. 2008. Spotlight on White-necked Picathartes: sustainable conservation by local communities in Sierra Leone. BirdLife International Africa Partnership e-bulletin 15: 3.
Asamoah, A. 2011. The Ecology, Distribution and Conservation of White-necked Picathartes, Picathartes gymnocephalus in Ghana. University of Ghana.
Owusu, E. H., Asamoah, A. 2008. New White-necked Picathartes (Picathartes Gymnocephalus) nesting areas in Ghana. Malimbus 30: 175-177.
Further web sources of information
International Action Plan
View photos and videos, and hear sounds of this species from the Internet Bird Collection
Text account compilers
Ekstrom, J., Shutes, S., Symes, A., Taylor, J.
Contributors
Asamoah, A., Borrow, N., Dowsett, R., Fishpool, L., Fotso, R., Gartshore, M., Rainey, H., Thompson, H., Tiedemann, R.
IUCN Red List evaluators
Butchart, S., Taylor, J.
Recommended citation
BirdLife International (2013) Species factsheet: Picathartes gymnocephalus. Downloaded from
http://www.birdlife.org on 19/06/2013.
Recommended citation for factsheets for more than one species: BirdLife International (2013) IUCN Red List for birds. Downloaded from
http://www.birdlife.org on 19/06/2013.
This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.
To provide new information to update this factsheet or to correct any errors, please email BirdLife
To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.
Additional resources for this species
| Key facts | |
|---|---|
| Current IUCN Red List category | Vulnerable |
| Family | Picathartidae (Rockfowl) |
| Species name author | (Temminck, 1825) |
| Population size | 2500-9999 mature individuals |
| Population trend | Decreasing |
| Distribution size (breeding/resident) | 389,000 km2 |
| Country endemic? | No |
| Links to further information | |
|
- Additional Information on this species - Climate change species distributions | |
|
|