Cephalophus ogilbyi 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Cetartiodactyla Bovidae

Scientific Name: Cephalophus ogilbyi
Species Authority: (Waterhouse, 1838)
Infra-specific Taxa Assessed:
Common Name(s):
English Ogilby's Duiker
French Céphalophe D'Ogilby
Spanish Duiquero De Ogilby
Taxonomic Notes: This species probably represents a species complex of three allopatric species. Indeed, one recognized subspecies, Brooke's Duiker (C. o. brookei), from West Africa, is now often regarded as a distinct species (Grubb and Groves 2001, Grubb 2005).

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): IUCN SSC Antelope Specialist Group
Reviewer(s): Mallon, D.P. (Antelope Red List Authority) & Hoffmann, M. (Global Mammal Assessment)
Based on figures in East (1999), one subspecies, containing about half of the total numbers remains stable while the other two are declining. It is unlikely therefore that the decline for the species as a whole has yet reached the threshold for listing as Near Threatened. However, habitat degradation and destruction and over-hunting are ongoing threats and if current trends continue, the status of Brooke’s Duiker and the nominate subspecies will decline further until both become confined to a few effectively protected areas such as Tai and Korup.
Previously published Red List assessments:
1996 Lower Risk/near threatened (LR/nt)
1994 Vulnerable (V)
1990 Vulnerable (V)

Geographic Range [top]

Range Description:Ogilby’s Duiker is known from four separate populations within the equatorial forest zone (East 1999; Wilson 2001; Kingdon in press):

C. o. brookei (Brooke's Duiker) ranges in Sierra Leone, south-east Guinea, Liberia, southern Côte d’Ivoire and Ghana, west of the Volta River;

The nominate subspecies occurs on Bioko Island, and then on the mainland in south-east Nigeria and south-west Cameroon;

The white-legged form of Ogilby’s Duiker, C. o. crusalbum, occurs in Gabon, mostly south of the Ogooué River, and is reported to occur in north-west Republic of Congo.
Countries occurrence:
Cameroon; Congo; Côte d'Ivoire; Equatorial Guinea; Gabon; Ghana; Guinea; Liberia; Nigeria; Sierra Leone
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:East (1999) produced an estimated total population of 35,000, including an estimated 5,000 Brooke’s Duikers, 12,000 C. o. ogilbyi and 18,000 of the white-legged form. Populations are probably decreasing throughout the ranges of Brooke’s Duiker and the nominate subspecies, with a few possible exceptions such as some protected areas. The White-legged Duiker’s numbers are probably stable in considerable parts of its range in Gabon and north-western Congo where human population densities are very low.
Current Population Trend:Decreasing
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:Its preferred habitat is primary moist lowland forest, yet it is common in forest patches within the forest-savanna mosaic. It has been recorded in areas with a mix of high forest and logged forest, or high forest and secondary forest (but seems to be very rare in highly modified secondary forest).

On Bioko, the species is not only present in lowland forest but also in the island’s montane forest (perhaps to elevations exceeding 2,000 m) and in the higher altitude Schefflera forest zone, habitats which are normally occupied by other duiker species on the mainland (East 1999).

Threats [top]

Major Threat(s): Threatened by habitat destruction (due to agriculture, human settlement, and logging) and intense hunting pressure, mainly by snaring for bushmeat. Although hunting takes place throughout the range, this is particularly severe on Bioko (see summary of bushmeat studies in Kingdon in press).

Conservation Actions [top]

Conservation Actions: Brooke''s Duiker is now known to exist in reasonable numbers in only a few areas, such as Sapo National Park and some other forests in eastern Liberia and Tai National Park in south-western Côte d'Ivoire.

The mainland population of the nominate subspecies has only a few remaining strongholds, e.g., Korup National Park (Cameroon) and Cross River N.P. (Nigeria); it has also been recorded from several forest reserves (Forboseh et al. 2007). It remains relatively numerous on Bioko Island (Equatorial Guinea). The effective protection of the Gran Caldera de Luba Scientific Reserve is crucial to the survival of this species on Bioko Island.

The distinctive White-legged Duiker is now known to be relatively widespread and numerous in Gabon, including protected areas such as Lope and the Gamba complex, and Odzala N. P. (Congo).

Listed on CITES Appendix II.

Classifications [top]

1. Forest -> 1.6. Forest - Subtropical/Tropical Moist Lowland
suitability: Suitable  
1. Forest -> 1.9. Forest - Subtropical/Tropical Moist Montane
suitability: Suitable  
2. Savanna -> 2.1. Savanna - Dry
suitability: Marginal  
2. Land/water management -> 2.1. Site/area management
3. Species management -> 3.1. Species management -> 3.1.1. Harvest management
3. Species management -> 3.1. Species management -> 3.1.2. Trade management

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
  Conservation sites identified:Yes, over entire range
In-Place Species Management
In-Place Education
  Included in international legislation:Yes
  Subject to any international management/trade controls:Yes
1. Residential & commercial development -> 1.1. Housing & urban areas
♦ timing: Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

2. Agriculture & aquaculture -> 2.1. Annual & perennial non-timber crops -> 2.1.4. Scale Unknown/Unrecorded
♦ timing: Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

5. Biological resource use -> 5.1. Hunting & trapping terrestrial animals -> 5.1.1. Intentional use (species is the target)
♦ timing: Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

5. Biological resource use -> 5.3. Logging & wood harvesting -> 5.3.5. Motivation Unknown/Unrecorded
♦ timing: Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

3. Monitoring -> 3.1. Population trends

♦  Food - human
 Local : ✓   National : ✓ 

Bibliography [top]

East, R. 1999. African Antelope Database 1999. IUCN, Gland, Switzerland and Cambridge, UK.

Forboseh, P. F., Eno-Nku, M. and Sunderland, T. C. H. 2007. Priority setting for conservation in south-west Cameroon based on large mammal surveys. Oryx 41: 255-262.

Grubb, P. 2005. Artiodactyla. In: D.E. Wilson and D.M. Reeder (eds), Mammal Species of the World. A Taxonomic and Geographic Reference (3rd ed), pp. 637-722. Johns Hopkins University Press, Baltimore, USA.

Grubb, P. and Groves, C. P. 2001. Revision and Classification of the Cephalophinae. In: V. J. Wilson (ed.), Duikers of Africa: Masters of the African Floor, pp. 703-728. Chipangali Wildlife Trust, Bulawayo,Zimbabwe.

Kingdon, J. 2013. Cephalophus ogilbyi. In: J. S. Kingdon and M. Hoffmann (eds), The Mammals of Africa, Academic Press, Amsterdam, The Netherlands.

Wilson, V. J. 2001. Duikers of Africa: Masters of the African Forest Floor. Directory Publishers, Bulawayo, Zimbabwe.

Citation: IUCN SSC Antelope Specialist Group. 2008. Cephalophus ogilbyi. In: The IUCN Red List of Threatened Species 2008: e.T4148A10462006. . Downloaded on 02 December 2015.
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