This species has a small population which constitutes a single metapopulation as there is presumed to be movement of individuals within its large range. It is listed as Vulnerable because information from across its range indicates that numbers are in decline owing to a variety of threats.
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.
Distribution and populationTrigonoceps occipitalis
Mid-sized, chunky vulture with predominantly blackish and white plumage as an adult. Strong colourful bill and rear-peaked head. Ruffed white legs and belly separated from downy white head by its striking black breast. Black ruff.
has an extremely large range in sub-Saharan Africa (from Senegal
disjunctly east to Eritrea
, and south to easternmost South Africa
), where it is uncommon to locally common, but generally widespread outside forested regions (Harrison et al.
1997). It has declined rapidly in parts of West Africa since the early 1940s (P. Hall in litt.
1999, J. M. Thiollay in litt
. 2006, 2012), is declining in East Africa (Virani et al.
2011) and in southern Africa is now largely confined to protected areas. In Botswana
only four nests were located during gyrocopter surveys of three Important Bird Areas during 2008 and the species has the lowest relative abundance of the vulture species recorded (Hancock 2008), while in Niger
there are only four records since 1995, all in the Gadabeji area (J. Brouwer in litt.
. The species has probably declined in central Mozambique
(Parker 2005a), where the population is estimated at 200 pairs (Parker 2005b). An extrapolated estimate of the global population suggested there were 2,600-4,700 pairs (7,000-12,500 mature individuals) (Mundy et al.
1992). Population justification
An estimate of 7,000-12,500 mature individuals was extrapolated from a number of regional estimates. This equates to 10,500-18,750 individuals in total, here rounded to 10,000-20,000 individuals.Trend justification
The species has shown severe declines throughout its West African range (F. Dowsett-Lemaire in litt. 2006; J.M. Thiollay in litt. 2006) and also across southern Africa (Ferguson-Lees et al. 2001), thus its global population is estimated to be declining at a slow to moderate rate.Ecology
It prefers mixed, dry woodland at low altitudes, avoiding semi-arid thornbelt areas (Mundy et al.
. It also occurs up to 4,000 m in Ethiopia, and perhaps 3,000 m in Kenya, and ranges across the thorny Acacia
-dominated landscape of Botswana (Mundy et al.
. It generally avoids human habitation (Mundy et al.
. The species is thought to be a long-lived resident that maintains a territory (del Hoyo et al.
. It may generally fly lower than other vultures, and is often the first vulture species to arrive at carcasses (Mundy et al.
. While it is often found on the periphery of vulture congregations at large carcasses, it is also often found at small carcasses and is probably an occasional predator (Mundy et al.
1992, F. Dowsett-Lemaire in litt.
. It nests and roosts in trees, most nests being in Acacia
spp. or baobabs (Mundy et al.
. Clutch size is one, the egg being laid a couple of months after rains have finished and the dry season is underway (Mundy et al.
. Pairs that breed have a success rate of 65-75%, however, up to 61% of pairs do not attempt to breed each year (Mundy et al.
1992, del Hoyo et al.
Reductions in populations of medium-sized mammals and wild ungulates, as well as habitat conversion throughout its range best explain the current decline (Mundy et al.
1992, P. Hall in litt.
1999, R. Davies in litt.
2006). Additional threats include indirect poisoning (R. Davies in litt.
2006) at baits set to kill jackals in small-stock farming areas, and in East Africa at poisoned baits set for larger mammalian carnivores such as lions and hyenas (C. Kendall in litt.
and, particularly in East Africa, secondary poisoning from carbofuran (Otieno et al.
2010), although this species may be less susceptible than other vultures owing to its broad diet. Exploitation for the international trade in raptors (N. Baker in litt
. 2006) also poses a threat. In 2005, 30 individuals of this species were confiscated by the Italian authorities (F. Genero in litt.
2005). In South Africa, this species is captured for use in traditional medicines (R. E. Simmons and C. J. Brown in litt.
2006). Breeding birds may readily desert nests in areas of high human disturbance (R. E. Simmons and C. J. Brown in litt.
2006). The species is highly sensitive to land-use and is highly concentrated in protected areas (Hancock 2008). Potential introduction of the non-steroidal anti-inflammatory drug diclofenac, which is fatal to Gyps
spp. when ingested at livestock carcasses may represent a potential future threat to the species.Conservation Actions Underway
This species currently occurs throughout much of southern and East Africa's protected areas network (F. Dowsett-Lemaire in litt.
2006). It is classified as vulnerable in Namibia and South Africa (R. E. Simmons and C. J. Brown in litt.
2006). Individuals were marked with patagial tags in Fouta Djallon vulture sanctuary, Guinea, in 2007 to monitor movements and for a toxicological assessment of the vulture population of the park (Rondeau 2008). In 2007, a survey began to establish the extent of diclofenac use for veterinary purposes in Tanzania (BirdLife International 2007), and in 2008 an awareness-raising campaign at a conference of the World Organisation for Animal Health in Senegal led to a resolution being adopted unanimously by more than 160 delegates to "request Members to consider their national situation with the aim to seek measures to find solutions to the problems caused by the administration of diclofenac in livestock" (Woodford et al.
2008).Conservation Actions Proposed
Carry out co-ordinated surveys throughout the range of this species to clarify its population size and trends. Raise awareness about the impact of poisoning on this species (R. E. Simmons and C. J. Brown in litt.
2006). Enforce anti-poisoning legislation (R. E. Simmons and C. J. Brown in litt.
2006). Minimise disturbance at nests (C. Kendall in litt.
2012). Eliminate the veterinary use of diclofenac and other toxic drugs in Africa. Limit the hunting of game to improve the availability of carrion. Carry out education and awareness programmes, particularly targetted at farmers, to reduce persecution, unintentional poisoning and hunting for cultural reasons.
Related state of the world's birds case studies
BirdLife International. 2008. Drugs firms told to do more to prevent vulture extinctions. Available at: #http://www.birdlife.org/news/news/2008/08/indian_drug_announcemment.html#.
del Hoyo, J.; Elliott, A.; Sargatal, J. 1994. Handbook of the Birds of the World, vol. 2: New World Vultures to Guineafowl. Lynx Edicions, Barcelona, Spain.
Ferguson-Lees, J.; Christie, D. A. 2001. Raptors of the world. Christopher Helm, London.
Harrison, J. A.; Allan, D. G.; Underhill, L. G.; Herremans, M.; Tree, A. J.; Parker, V.; Brown, C. J. 1997. The atlas of southern African birds. BirdLife South Africa, Johannesburg.
Mundy, P.; Butchart, D.; Ledger, J.; Piper, S. 1992. The vultures of Africa. Academic Press, London.
Otieno, P. O.; Lalah, J. O.; Virani, M., Jondiko, I. O.; Schramm, K. 2010. Carbofuran and its toxic metabolites provide forensic evidence for Furadan exposure in vultures (Gyps africanus) in Kenya. Bulletin of Environmental Contamination and Toxicology 84: 536-544.
Parker, V. 2005. The atlas of the birds of central Mozambique. Avian Demography Unit and Endangered Wildlife Trust, Cape Town and Johannesburg.
Parker, V. 2005. Endangered Wildlife Trust and Avian Demography Unit, Johannesburg, South Africa.
Rondeau, G. 2008. Tagged vultures in Fouta Djallon, Guinea. Vulture News: 56.
Virani, M.; Kendall, C.; Njoroge, P.; Thomsett, S. 2011. Major declines in the abundance of vultures and other scavenging raptors in and around the Masai Mara ecosystem, Kenya. Biological Conservation 144: 746-752.
Woodford, M. H.; Bowden, C. G. R., Shah, N. 2008. Diclofenac in Asia and Africa â€“ repeating the same mistake? Harmonisation and improvement of registration and quality control of Veterinary Medicinal Products in Africa - OIE World Organisation for Animal Health.
Text account compilers
Bird, J., Butchart, S., Ekstrom, J., Evans, M., Harding, M., Martin, R, Pilgrim, J., Taylor, J., Symes, A.
Baker, N., Barlow, C., Bowden, C., Brown, C., Davies, R., Dowsett, R., Dowsett-Lemaire, F., Genero, F., Hall, P., Ndang'ang'a, P., Pomeroy, D., Simmons, R., Thiollay, J., Wolstencroft, J., Brouwer, J., Kendall, C.
IUCN Red List evaluators
Butchart, S., Taylor, J.
BirdLife International (2014) Species factsheet: Trigonoceps occipitalis. Downloaded from
http://www.birdlife.org on 16/04/2014.
Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from
http://www.birdlife.org on 16/04/2014.
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
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Additional resources for this species