Kobus kobkob

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Geographic Range

Kobus kob occurs in the moist savannah zones of Africa, from Senegal to western Kenya (Nowak 1991).

Habitat

Kob are usually found near permanent water sources (Deutsch 1994a). They frequent moist savannah, floodplains, and the margins of adjacent woodlands. Elevated areas with short grass are the preferred habitat for lek sites (Deutsch and Weeks 1992).

Females prefer high-visibility mating sites with short grasses and few thickets. This preference may serve to avoid lion predation (Deutsch and Weeks 1992), though Balmford and Turyaho (1992) disagree.

Physical Description

Standing aproximately 92 cm high at the shoulder, Kobus kob has a short, reddish-brown coat, with a white throat-patch and white underparts. A distinctive black stripe marks the front of the forelegs (Stuart and Stuart 1992). Horns average 44 cm in length and are ridged with transverse corrugations. They are curved, turning up at the tips. Only males carry horns (Smith 1985). The multiple subspecies that comprise Kobus kob are distinguished primarily by variation in pelage darkness (Meester and Setzer 1971). (Meester and Setzer, 1971; Smith, 1985; Stuart and Stuart, 1992)

  • Range mass
    90 to 120 kg
    198.24 to 264.32 lb

Reproduction

Kob usually have a lek mating system, in which males defend small territories clustered on traditional mating grounds. Females visit these leks only to breed, and males provide no parental care. This mating system may have evolved because males cannot defend the widely-dispersed food resources or the dynamic and temporary female herds (Deutsch 1994a).

Within a lek, 20 to 200 males defend territories 15 to 200 meters in diameter (Nowak 1991). Male territories are smallest and most highly-contested in the center of the lek, where most matings occur. These territories maintain their popularity among females despite rapid male turnover (Deutsch 1994a). In areas of lower population density, males are spaced farther apart and hold their territories for longer periods of time (Nowak 1991; see below for further discussion of the effects of population density on mating system).

Each lek is associated with a female herd of about 100 individuals. Females begin to mate at the age of one, but males must normally wait for several more years (Nowak 1991). Larger numbers of females associate with larger leks, possibly because females stay on the lek longer when more males and other females are present (Deutsch 1994b).

Females give birth to a single offspring after a gestation period of around 9 months. Calving season may vary with location, but the Boma population of Uganda kob gives birth at the end of the rains, in November-December (Nowak 1991).

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • sexual
  • Range number of offspring
    1 (low)
  • Average number of offspring
    1
  • Average number of offspring
    1
    AnAge
  • Range gestation period
    7.87 to 8.9 months
  • Range weaning age
    6 to 7 months
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    403 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    365 days
    AnAge

Lifespan/Longevity

Behavior

Kob are mostly active in morning and evening hours. They form mixed-sex herds of females and young males (< 8 months) that may vary greatly in size over short time periods. Females occupy large, overlapping home ranges, apparently moving in response to food availability. Males' movements are more restricted, and they commonly remain close to lek areas (Balmford 1992). Herds of non-breeding males may also form. Populations vary widely in density; 8 to 124 kob per square km have been reported in suitable habitat (Muhlenberg and Roth 1985). This variation in density affects male mating strategies. Males may move in herds, have single territories, or defend lek territories (Deutsch 1994a). Higher populations favor lek mating. Kob on the Ivory Coast, which has low popualtion densities, do not lek (Muhlenberg and Roth 1985).

Kob may migrate to graze along watercourses. One population in SE Sudan traveled 150-200 km in the dry season (Nowak 1991). Populations may reach great densitites (1000 kob/sq km) during these migrations (Fryxell and Sinclair 1988).

Communication and Perception

Food Habits

Kob are herbivorous. They eat grasses and reeds, and may migrate great distances to graze along watercourses (Fryxell and Sinclair 1988).

Economic Importance for Humans: Positive

Kob are commonly hunted for sport and food. A survey of bushmeat preferences in Cameroon ranked kob as the third most favored species, second only to North African porcupine and guinea fowl (Njiforti 1996).

  • Positive Impacts
  • food

Economic Importance for Humans: Negative

No negative effects are described in the literature

Conservation Status

Meester and Setzer (1971) report the range of the species as greatly diminished, but kob are still common in national parks (Njiforti 1996). Kob in the Boma grassland ecosystem form the second largest population of antelope in Africa (East 1988).

Kob are hunted by lions (/Panthera leo/), spotted hyenas (/Crocuta crocuta/), human poachers, and wild dogs (/Lycaon pictus/) (Deutsch and Weeks 1992).

Muhlenberg and Roth (1985) list a series of management recommendations to maintain kob at their present population levels: (1) grassland habitat near rivers should be left undeveloped for grazing and access to water, (2) hunting should focus on bachelor males rather than the easily-obtained territorial males, and (3) simgle females should not be harvested, as they are likely to be in estrous or caring for young.

Other Comments

The name Adenota has sometimes been used to denote a genus or subgenus comprising K. kob and K. vardoni (Nowak 1991). Kobus kob includes at least ten described subspecies (Meester and Setzer 1971). The most widely recognized of these are the Uganda kob (/K. kob thomasi/), the white-eared kob (/K. kob leucotis/), and the Buffon's or Western kob (/K. kob kob/).

Contributors

Emily DuVal (author), University of California, Berkeley, James Patton (editor), University of California, Berkeley.

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

food

A substance that provides both nutrients and energy to a living thing.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

sexual ornamentation

one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

References

Balmford, A. 1992. Social Dispersion and lekking in Uganda kob. Behaviour, 120 (3-4): 177-191.

Balmford, A., M. Turyaho. 1992. Predation risk and lek-breeding in Uganda kob. Animal Behaviour, 44: 117-127.

Deutsch, J. 1994a. Lekking by default: female habitat preferences and male strategies in Uganda kob. Journal of Animal Ecology, 63: 101-115.

Deutsch, J. 1994b. Uganda Kob mating success does not increase on larger leks. Behavioral Ecology and Sociobiology, 34: 451-459.

Deutsch, J., P. Weeks. 1992. Uganda kob prefer high-visibility leks and territories. Behavioral Ecology, 3 (3): 223-233.

East, R. 1988. Antelopes: Global Surveya nd Regional Action Plans. Part 1 East and Northeast Africa.. Gland, Switzerland: IUCN.

Fryxell, J., A. Sinclair. 1988. Seasonal migration by white-eared kob in realtion to resources. Arfican Journal of Ecology, 26: 17-31.

Meester, J., H. Setzer. 1971. Mammals of Africa: an identification manual. Washington, DC: Smithsonian Institution Press.

Muhlenberg, M., H. Roth. 1985. Comparative investigations into the ecology of the kob antelope Kobus kob kob (Erxleben 1777) in the Comoe National Park, Ivory Coast. South African Journal of Wildlife Research, 15 (1): 25-31.

Njiforti, H. 1996. Preference and present demand for bushmeat in north Cameroon: some implications for wildlife conservation. Environmental Conservation, 23 (2): 149-155.

Nowak, R. 1991. Walker's Mammals of the World, fifth edition. Baltimore, MD: The Johns Hopkins University Press.

Smith, S. 1985. The atlas of Africa's Principal Mammals. San Antonio: Natural History Books.

Stuart, C., T. Stuart. 1992. Southern, Central, and East African Mammals: A photographic guide. Cape Town, South Africa: Struik Publishers.