Connochaetes gnoublack wildebeest(Also: white-tailed gnu)

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Geographic Range

Originally, black wildebeest, or white-tailed gnus, ranged the highveld temperate grasslands during the dry winter and the arid karroo during the rains. However, due to hide-hunting in the 19th century, they were reduced to living on protected game farms in southern Africa. (Estes, 1991)

Habitat

Connochaetes gnou lived in grasslands similar to the habitat of the common wildebeest, Connochaetes taurinus, when it ranged free. However, with its thicker, darker coat, black wildebeest are able to range farther south than the Orange River, past the edge of the acacia savannah, into colder climates. They rarely seek shade, and need little winter shelter. (Estes, 1991)

Physical Description

Black wildebeest are dark brown to black in color, males being darker in color than females. Both sexes become lighter in coat color in the summer, and develop shaggier coats in the winter. Like common wildebeest, C. gnou possesses a bushy beard and mane. However, C. gnou has a mane that stands up from its neck, rather than draping across the neck, like that of C. taurinus. This bristly mane is cream to white in color and black at the tips. The beard is black in color and stretches only along the lower jaw, not the length of the neck, as in C. taurinus. Additionally, black wildebeest have an area of longer, dark hair between the forelegs, covering the chest, and another patch of bristly black hair along the bridge of the nose. Male C. gnou stand 111 to 121 cm high and can be up to 2m in length, females are slightly smaller. Paired horns curve down, forward, and then up, like hooks, and are up to 78 cm in length (slightly thinner and shorter in females). The base of the horns is widened and flattened to form a protective shield. These differ from C. taurinus in that they project anteriorly, rather than laterally. Scent glands are present preorbitally, under the hair tuft, and on the forefeet.

Dental formula: 0/3, 0/1, 3/2, 3/3 (Talbot 1963) (Estes, 1991; Talbot and Talbot, 1963; Walker, 1968)

  • Range mass
    110 to 157 kg
    242.29 to 345.81 lb
  • Range length
    2 (high) m
    6.56 (high) ft

Reproduction

Dominant males defend access to a harem of females with which they mate. These territorial bulls are able to mate at any time, will call at twice the normal tempo, and may even froth at the mouth. There is suggestion that this calling helps to stimulate and synchronize female estrus, although there is also evidence that the lunar cycle triggers the mating peak. A rutting bull will never eat nor rest, as long as there are females within his territory. There are few courting rituals, besides males herding females with neck outstretched and chin in-line, urination on demand and flehmen (urine scenting). If a receptive female is uncooperative, a bull may rear in front of her with a full erection in a copulatory display. A receptive female will raise her tail when approached by a bull, swishing it across his face. Her tail remains up, sometimes, vertical, during mating, as the cow stands with her legs bowed, back arched. Females mate dozens of times with a male, often 2 or more times in a minute. (Estes, 1991)

Offspring gestate for 8 to 8.5 months, only 1 extremely precocial calf is born. Calving peaks in November-December (semi-dependent on timing and location of rains). Like C. taurinus, 80-90% of all calves are dropped within the three week birth peak. Calves can stand at 9 minutes post-parturition, and are grazing at least part time within one month. Calves are weaned after 4 months. Females mature at 1.5 to 2.5 years of age, males don't mature until 3 years of age.

  • Breeding interval
    Females breed once yearly.
  • Breeding season
    The breeding season coincides with the end of the rainy season, February to April.
  • Range number of offspring
    1 to 2
  • Average number of offspring
    1.02
  • Average number of offspring
    1
    AnAge
  • Range gestation period
    8 to 8.5 months
  • Range weaning age
    6 to 9 months
  • Range age at sexual or reproductive maturity (female)
    1.5 to 2.5 years
  • Average age at sexual or reproductive maturity (male)
    3 years

Like most mammals, female black wildebeests nourish their young in utero, and then nurse them for several months after birth. Males provide no care for their young. Calves stay with their mothers until the next calf is born. Black wildebeest calves are capable of standing and running within hours of birth.

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • protecting
      • female
  • post-independence association with parents

Lifespan/Longevity

Black wildebeest can live for 20 years.

Behavior

Like C. taurinus, wild C. gnou were migratory in large herds. Black wildebeest were never studied in their natural habitat, interacting with natural predators, however they seem to be more aggressive than their wild cousins, and have attacked and killed keepers while in captivity. The largest existing herd numbers 330 head at Willem Pretorius Game Reserve, Orange Free State. Herd size increases with forage density, female herds ranging from 14 to 32 and maintain a social dominance hierarchy. Unlike common wildebeest, black wildebeest do not groom each other or rub their foreheads on other wildebeest's croups because of the projection of their horns. However, they occasionally rub their cheeks on companions' necks.

Calves stay with their mothers until the next calf is born. These yearlings are driven out by the adult males. During this process, calves are often separated from their mothers, resulting in what may be the main cause of captive calf mortality. The yearlings form peaceful bachelor herds that may be tolerated by female groups late in the dry season. (Estes, 1991; Huffman, 2004; Walker, 1968)

Home Range

Black wildebeest herds maintain a range of approximately 100 ha, dependending on the availability of space and quality of vegetation.

Communication and Perception

Male wildebeest determine dominance through classic head-ramming and front-pressing behaviors exhibited in most bovids, however the females maintain their rank primarily through head-nods and head-shakes. The white tail is lashed or waved in most C. gnou interactions, signalling anything from dominance to submission, and possibly serving as an auditory signal, as it can be heard up to half a kilometer away.

Food Habits

Black wildebeest eat the foliage of karroid bushes and shrubs. They live in somewhat arid regions and can subsist without drinking every day. (Estes, 1991)

  • Plant Foods
  • leaves
  • wood, bark, or stems
  • flowers

Ecosystem Roles

Black wildebeest were once important herbivores in the ecosystems in which they live and served as an important prey base for large predators, especially in calving seasons.

Economic Importance for Humans: Positive

Black wildebeest are part of the diverse wildlife that attracts tourists for safari.

Economic Importance for Humans: Negative

Wild gnu are seen as competitors of commercial livestock. As well, many bovine diseases, such as rinderpest, travel from wildebeest to cattle. Wildebeest also carry parasites, including several kinds of ticks, flies, lungworms, tapeworms, and paramphistome flukes. (Talbot and Talbot, 1963)

Conservation Status

Indiscriminate hunting and restriction of the best fertile land for farming has reduced the population sizes of many African antelope, including this species. Connochaetes gnou now exists only in contained populations on game farms and in zoos (Macdonald 1995). The IUCN rates it a species of Least Concern because of the large number of captive individuals. (Macdonald, 1995)

Contributors

George Hammond (editor), Animal Diversity Web, Tanya Dewey (editor), Animal Diversity Web.

Barbara Lundrigan (author), Michigan State University, Jennifer Bidlingmeyer (author), Michigan State University.

Glossary

Ethiopian

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

World Map

acoustic

uses sound to communicate

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.

causes or carries domestic animal disease

either directly causes, or indirectly transmits, a disease to a domestic animal

chemical

uses smells or other chemicals to communicate

diurnal
  1. active during the day, 2. lasting for one day.
dominance hierarchies

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

ecotourism

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.

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.

folivore

an animal that mainly eats leaves.

food

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

herbivore

An animal that eats mainly plants or parts of plants.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

migratory

makes seasonal movements between breeding and wintering grounds

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.

polygynous

having more than one female as a mate at one time

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

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

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

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.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

Estes, R. 1991. The Behavior Guide to African Mammals. Berkeley, Los Angeles, London: University of California Press.

Huffman, B. 2004. "Connochaetes gnou" (On-line). The Ultimate Ungulate Homepage. Accessed 09/09/04 at http://www.ultimateungulate.com/Artiodactyla/Connochaetes_gnou.html.

Macdonald, D. 1995. Encyclopedia of Mammals. London, Sydney: George Allen and Unwin.

Talbot, L., M. Talbot. 1963. The Wildebeest in Western Masailand. Wildlife Monographs, 12: 8-88.

Walker, E. 1968. Mammals of the World. Baltimore: Johns Hopkins Press.