Steenbok (Raphicerus campestris)

Steenbok

Raphicerus campestris (Thunberg, 1811)

Steenbok female

Photo: Doug Lee

Afrikaans:Steenbok
German:Steinböckchen
French:Steenbok
Swahili:Isha / Dondor
isiNdebele:Ingina
isiZulu:Iqhina
isiXhosa:Itshabanqa
seSotho:Thiane
seTswana:Phuduhudu
Shona:Mhene Ndunguza / Chengu
Shangaan:Shipene Ndakadsi
Nama:!Aris

IUCN Conservation Status:

Survival threat rating: Lower Risk, least concerned (LR/lc)

This graceful buck has the misfortune to be named after a brick, perhaps because of its colour, and is the symbol of cleanliness among the African people. It has the second widest distribution of African antelope due to its ability to survive in marginal areas where larger, faster and more aggressive ungulates have disappeared following human pressure. In addition, its ability to feed almost exclusively on forbs in otherwise totally degraded and overgrazed habitat contributes significantly to its survival.

Taxonomy

Classification

Class:MAMMALIA
Supercohort:LAURASIATHERIA
Cohort:FERUNGULATA
Superorder:CETARTIODACTYLA
Order:RUMINANTIA
Suborder:PECORA
Superfamily:Bovoidea
Family:Bovidae
Subfamily:Bovinae
Tribe:Neotragini (Dwarf antelope)
Genus:Raphicerus
Species:campestris

The genus includes three species and two subspecies namely:

  • Raphicerus campestris, the steenbok
  • Raphicerus melanotis, the Cape grysbok
  • Raphicerus sharpei sharpei, Sharp’s grysbok
  • Raphicerus sharpei colonicus, the tropical grysbok

Former authors have recognised 12 sub-species of steenbok these being Raphicerus campestris bourguii, R.c. cunenensis, R.c. hoamibensis, R.c. horstockii, R.c. kelleni, R.c. natalensis, R.c. neumanni, R.c. steinhardti, R.c. stigmatus, R.c. tragulus, R.c. ugabensis and R.c. zukowskyi. Only six of these occur in the southern African sub-region. Taxonomic revision of the different sub-species is long overdue as there are only minute distinguishable differences between them.

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Description

It is a small gracious antelope with relatively long legs and a slender body. The skin is smooth, pale red-brown on the back and the belly and inner thighs a contrasting bright white. A darker brown, Y-shaped marking can sometimes be seen on the forehead. Ewes have four teats. Adult body size is reached within 14 to 20 months of age.

Comparison To Man

Wildlife Ranching Steenbok comparison to man

Trophy

Only rams bear fully developed horns. These are simple, straight and spaced widely apart. The tips are incredibly sharp and slightly bended forward. Most of the length is smooth except for two or three rings directly above the base. Ewes with deformed and inferior horns do occur.

Habitat requirement

Open and gently undulating plains with scattered trees and shrubs and a short to medium height (2-12 cm) grass layer of sweet, palatable, highly digestible grass species are favoured. Sourveld is completely avoided. The most suitable veld types occur within semi-arid savannahs, succulent Karoo and grasslands. The steenbok usually avoids rocky slopes, steep mountains, rugged country, sand-deserts, thickets and forests. Climatic conditions can vary from semi-arid (less than 200 mm annual rainfall) in the Kalahari, to sub-tropical (500-1 200 mm rainfall), with extreme temperatures of -10 degrees C to 50 degrees C. Patches of tall grass and scattered shrubs should be available as cover for protection. Disturbed areas such as roadsides, firebreaks, landing strips, the edges of cultivated lands and overgrazed patches are mostly favoured due to the abundance of pioneer, broadleaf forbs. Steenbok are totally independent of drinking water.

Optimum vegetation structure is the following canopy foliage cover:

  • 40-80% cover between a height of 0 and15 cm
  • 20-30% cover between 15 and 30 cm
  • 15% cover between 30 and 45 cm
  • 5% cover between 45 and 75 cm
  • <5% cover above 75 cm.

Distribution

Wildlife Ranching Steenbok distribution maps

Feeding & Nutrition

The steenbok is a ruminant and a mixed feeder of both broadleaf forbs and short sweet palatable grasses of less than 12 cm that are low in fibre content. In the Kruger National Park its diet consists of 155 dicot forb species, 42 tree and shrub species, 15 creeper species and 20 grass species. It is a highly selective concentrate feeder with a definite preference for specific, most delicate, parts of plants. The feeding behaviour is dictated to by a high metabolic rate which requires a high protein and soluble carbohydrate intake. In general the diet consists 67% of dicot forb browse, 19% tree and shrub browse and 6% creeper browse and only 8% grass. However, studies on captive animals indicate that they prefer to browse exclusively, although in some habitats grass can form up to 50% of the diet. Steenbok are also known to dig for underground bulbs and succulent roots, especially in semi-arid environments. They drop down on the knees to feed at ground level and are strongly attracted to new growth on recently burnt veld. The mean feeding height for the steenbok is 21 cm, ranging from 0-53 cm. They are diurnal and remain active until 2-3 hours after sunset when they lie down under thicket, in tall grass patches or in old aardvark burrows. On moonlight nights feeding may extend later into the dark. Growing human disturbance has caused them to become increasingly nocturnal.

Social structure

Steenbok are mostly solitary or occur in male/female or mother/lamb pairs. They are strictly territorial, with the adult ram and ewe each having a separate, fixed territory. Frequent sightings of the same individuals in pairs in the same vicinity are a result of temporary meetings when individuals pass through the overlaps of adjacent home ranges. Such incidents can last up to three days and are frequently repeated. Pairs frequently form between the same individuals but only for courtship and mating purposes or as a mother with her lamb The common rapid development of horns in male lambs also contributes to the misconception of pair-bonding, as the ewe is seen in close association with her son for an extended period giving a false impression of adult pair-bonding.

Information Table


Steenbok information table
Characteristic
Ram
Ewe
Adult body weight
kg
9-13
10-13.5
Adult shoulder height
cm
43-50
45-54
Expected longevity
years
9
6-8
Age of sexual maturity
months
9
6-7
Age of social adulthood (1st mating)
months
13-18
7-9
Gestation
days

165-175
1st lamb born at
years

13-15
Lambing interval
months

8-10
Post maturity age (last mating)
years
-
-
Rutting season
Year round (peak Feb-May)
Lambing season:
Year round (peak Sep-Dec)
Weaning age months
3-4
Gender ratio: natural (all ages)
2
1
Gender ratio: production (all ages)
1
1
Mating ratio: natural (adults)
1
1
Mating ratio: production (adults)
1
1.5
Re-establishment: absolute minimum number needed
2
2
Re-establishment: smallest viable population size
3
3
Spatial behaviour: home range
ha
12-30
12-30
Spatial Behaviour: territory range
ha
3-15
5-15
Large stock grazing unit (adult):
Dietary ratio (grass):
LSU
0.06 per animal
(34% Of diet)
0.06 per animal
(34% of diet)
Browsing unit (adult):
Dietary ratio: (browse):
BU
1.14 per animal
(66% of diet)
1.14 per animal
(66% of diet)
Maximum stocking load
80 animals per 1000 ha (At 400-800 mm annual rainfall)
Minimum habitat size required
ha
10
Annual population growth 21-32% (mean 27%)
Optimal annual rainfall
300-600 mm
Optimal vegetation structure:
Grass height:
Woody canopy cover:

0-12 cm
0-40%

Bibliography

  1. Cloete, G, 1983. Etho-ecological aspects of the steenbok in the Namib desert, South West Africa. M.SC. thesis, University of the Orange Free State.
  2. Cloete, G & Kok, OB, 1986. Aspects of the water economy of steenbok in the Namib desert. Madoqua 14:375-387.
  3. Cloete, G & Kok, OB, 1990. Aspects of the behaviour of steenbok in the Kuiseb River Canyon, S.W.A./Namibia. J. Nam. Sci. Soc. 42:25-46.
  4. Cohen, M, 1987. Aspects of the biology and behaviour of the steenbok in the Kruger National Park. D.Sc. thesis, University of Pretoria.
  5. Du Plessis, SF, 1969. The past and present geographical distribution of the Perrisodactyla and Artiodactyla in Southern Africa. M.Sc. Thesis, University of Pretoria.
  6. Du Toit, JT, 1993. The feeding ecology of a very small ruminant, the steenbok. Afr. J. Ecol. 31:35-48.
  7. Du Toit, JT, 1990. Home range-body mass relations: a field study on African browsing ruminants. Oecologia 85:301-303.
  8. Furstenburg, D 2003. Steenbok Rhapicerus campestris. Game & Hunt 9(3):6-11.
  9. Furstenburg, D, 2005. The Steenbok. In: Intensive Wildlife Production in Southern Africa, Eds. Bothma, J Du P & N Van Rooyen. Van Shaik Publishers, Pretoria, pp. 248-256.
  10. Haim, A & Skinner, JD, 1991. A comparative study of metabolic rates and thermoregulation of two African antelopes, the steenbok and the blue duiker. J. Therm. Biol. 16:145-148.
  11. Huntley, BJ, 1972. A note on food preferences of a steenbok. J. Sth Afr. Wildl. Mgmt Ass. 2:24-26.
  12. IEA (Institute of Applied Ecology), 1998. Raphiceros. In African Mammals Databank - A Databank for the Conservation and Management of the African Mammals Vol 1 & 2. European Commission Directorate, Bruxelles.
  13. IUCN, 2006. IUCN Red list of Threatened Species, Gland, Switzerland.
  14. Kingdon, J, 1997. The Kingdon Field Guide to African Mammals. Princeton University Press, Princeton.
  15. Nowak, RM, 1991. Walker's Mammals of the World 5th edn. The Johns Hopkins University Press, Baltimore.
  16. Robinson, MD, 1977. An observation on parental care of young in the steenbok in South West Africa. Madoqua 10:215-216.
  17. Skead, CJ, 1987. Historical Mammal incidence in the Cape, Vol 1 & 2, Government Printer, Cape Town.
  18. Skinner, JD & Chimba, CT, 2005. The Mammals of the Southern African Subregion, 3rd edn. Cambridge University Press.
  19. Ward, R, 2006. Rowland Ward’s Records of Big Game, 27tth edn. Rowland Ward Publications.
  20. Wikipedia Encyclopedia, 2008. Connochaetus.
  21. Wilson, VJ & Kerr, MA, 1969. Brief notes on reproduction in steenbok. Arnoldia Rhod. 4(23):1-5.
  22. Wilson, DE & Reeder, DM, 1993. Mammal Species of the World: A Taxonomic and Geographic Reference. 2nd edn., Smithsonian Institution Press, Washington.
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