Raphicerus melanotis

Geographic Range

Cape grysboks, Raphicerus melaotis , are endemic to South Africa. They inhabit a small range from Zululand to Cape Province.

• Biogeographic Regions
• ethiopian ethiopian
  • native native

Habitat

Cape grysboks prefer open grassy plains for foraging and thick areas of bush for hiding during the day. They range from arid savannahs to moist reed belts.

• Habitat Regions
• temperate temperate
• terrestrial terrestrial

• Terrestrial Biomes
• savanna or grassland savanna or grassland
• scrub forest scrub forest

• Other Habitat Features
• suburban suburban
• agricultural agricultural

Physical Description

Closely resembling Raphicerus campestris , or steenboks, cape grysboks are small antelopes. These animals are rather stocky, measuring 45 to 55 cm at the shoulder, and weighing between 8 and 23 kg. Straight, needle-like horns of 6.5 to 13 cm are found only on males, which are also darker in color than are females. The pelt is comprized of stiff, wiry hairs. Both adults and young have reddish-brown pelage dorsally, with a red underside and a reddish-yellow throat. White hairs sprinkled along the back, from the nape to the tops of the legs, give these antelopes a grizzled appearance. A dark Y-shaped marking can be found running from the forehead down to the nape of the neck. The ears are large with white radial stripes on the inside. The lateral hooves are very small and sometimes absent and small false hooves are present. Foot glands and pre-orbital glands are present and well developed.

• Other Physical Features
• endothermic endothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger
• male more colorful
• ornamentation ornamentation

Reproduction

No specific breeding season is recorded for grysboks. However, males are reported to be completely intollerant of one another. They fight feircely, and cannot be housed together in captivity. In addition, males are territorial, and mark their territories with dung heaps, scent marks, and urine. Pairs may associate and defend territories together. This indicates that mating is probably polygynous or monogamous.

Young are seen year round, however there is a peak from September through December. One young is born after a six-month gestation. Other details of reproduction and rearing have not been observed but are presumed similar to those of steenboks.

• Key Reproductive Features
• iteroparous iteroparous
• year-round breeding year-round breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
• viviparous viviparous

Parental care is reported to be similar to that of steenboks. Studies have not been further conducted with grysboks. it is likely that the female nurses, protects, and grooms her offspring. The role of the father in parental care has not been reported.

• Parental Investment
• no parental involvement
• altricial altricial
• pre-fertilization
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female
• pre-independence
  • protecting
    • female

Lifespan/Longevity

Grysboks have lifespans similar to Raphicerus campestris .

Behavior

Cape grysboks are generally nocturnal, becoming active late in the afternoon. They seek out open areas for grazing under the cover of darkness. During the day, they can be found resting in bushes or in the shade of rocks. They are reported to be solitary animals, with their only sociality during mating. When threatened, grysboks will lie flat in the grass. If pursued, these animals will run with a zigzag-gallop and dive into a hole to avoid predation. Vocalizing (in the form of bleating screams) only occurs when an individual is caught.

• Key Behaviors
• terricolous
• nocturnal nocturnal
• crepuscular crepuscular
• motile motile
• sedentary sedentary
• solitary solitary
• territorial territorial

Home Range

Each animal has a well-defined home territory. These are marked with defecation/urination sites and pre-orbital gland scent markings. Population density is low, with approximately one animal per square mile

Communication and Perception

Scent marking is the main form of communication among grysboks. They have very well developed preorbital glands that secrete a sticky, black substance with a distinct odor. However, as mammals, it is likely that there are some other forms of communication. Tactile communication occurs between mates, parents and offspring, and between rivals when fighting. Visual signals, based on body posture, probably are important as well.

• Communication Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

• Other Communication Modes
• scent marks scent marks

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Grapevine shoots are the preferred diet of Cape grysboks. They also ingest grasses, fruits, and bush and tree foliage. These antelope are reportedly able to survive long periods without water, and some home ranges have no free water in them.

• Primary Diet
• herbivore herbivore
  • folivore folivore

• Plant Foods
• leaves
• roots and tubers
• fruit

Predation

Because of their small size, grysboks fall prey to many animals. They are hunted by leopards, jackals, crowned eagles, and pythons, as well as humans.

The antipredator behavior of these animals is larely based on their small size. These animals try to hide from predators in vegetation, perhaps in the hopes of going unnoticed. If pursued, they will try to go down a hole, such as those made by aardvarks.

Ecosystem Roles

Cape grysboks are a prey item for a number of large carnivores. They probably have some influence on plant growth through their browsing behaviors.

Economic Importance for Humans: Positive

Cape grysbok are a common game animal, with trophy prices ranging from $300 to $900 US dollars. They are hunted with dogs. Although these animals may sometimes be eaten, the meat is reported to be dry and is not highly desired.

• Positive Impacts
• body parts are source of valuable material

Economic Importance for Humans: Negative

There are claims it that grysboks damage crops, however this is not seen as a substantial issue.

• Negative Impacts
• crop pest

Conservation Status

IUCN Red List Threatened Animals 1996 - Conservation dependent

Other Comments

Cape grysboks have very sharp hearing, which helps them remain elusive. They seem to adapt well to the presence of humans, but prefer to inhabit areas with little human development.

Additional Links

Encyclopedia of Life

Contributors

Nancy Shefferly (editor), Animal Diversity Web.

Lindsey Fowler (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor, instructor), University of Wisconsin-Stevens Point.

References

Dorst, J., P. Dandelot. 1969. A Field Guide to the Larger Mammals of Africa . Boston: Houghton Mifflin Company.

Haltenorth, T., H. Diller. 1980. The Collins Field Guide to the Mammals of Africa Including Madagascar . Lexington: The Stephen Greene Press.

Kingdon, J. 1982. East African mammals: An atlas of evolution in Africa. . London: Academic Press.

Nowak, R. 1999. Walker's Mammals of the World, Sixth Edition . Baltimore and London: The Johns Hopkins University Press.

ICI. 2002. "ICI Naturelink" (On-line ). Accessed 10/28/02 at http://www.ici.com/icishe/naturelink/species/species2321.htm .

Sutton Safaris. 2002. "Trophy Hunting" (On-line ). Sutton Safaris. Accessed 10/28/02 at http://suttonsafaris.eci.co.za/Trophies.htm .