Top predators of African grasslands are threats to the gemsbok. These include lions, cheetahs, leopards, and spotted hyenas. Even hunting dogs will attack them. Humans occasionally hunt these animals. The primary response to predation is flight, despite impressive weaponry. The young are typically targeted, since attacking the adults involves a risk of puncture wounds. However, it is debatable whether or not fatal stab wounds have ever been inflicted upon a predator, or whether predators show any avoidance of gemsbok in general. Predation may account for the high mortality rate in young. In the northern part of their range, 80% of spotted hyena kills are gemsbok calves.
Known Predators:
Gemsbok are large bovids with very thick, muscular necks, covered in dense, inelastic skin. Oryx gazella is the largest of the Oryx species. Gemsbok measure 115 to 125 cm high at the shoulder, and have total body lengths between 180 and 195 cm. Females weigh from 180 to 225 kg, whereas males are slightly larger, weighing between 180 and 240 kg. The slightly curved, ringed horns range from 60 to 150 cm in length. The horns of females are often shorter and more slender than those of males.
Black markings on the face extend down from the base of the horns to above the muzzle, and sweep back in stripes over the eyes and cheeks. Black continues down the neck and around the underbody, forming bands around all four legs. A stripe also runs up the spine, starting at the tip of the tail and ending at a short thick mane of black. There are black markings on the front of all four legs. The lower portion of the legs, muzzle, and underbelly are all white, whereas the body and neck are a gray or tan color. In instances of high productivity grazing, fat deposits under the skin become noticeable.
Inidividuals in northern populations have characteristic black tufts on the ears and are generally darker in color with thinner black markings than are individuals from southern populations.
Gemsbok are able to increase their body temperature to 45 degrees from 35.7 degrees C in order to delay evaporative cooling.
Range mass: 180 to 240 kg.
Range length: 180 to 195 cm.
Other Physical Features: endothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: male larger
The average life span is approximately 18 years in the wild, and 20 in captivity.
Average lifespan
Status: wild: 18 years.
Average lifespan
Status: captivity: 22 years.
Average lifespan
Status: captivity: 20.0 years.
Gemsbok are found at elevations from 900 to 1,200 meters, in wooded grasslands as well as wetter grasslands. They can survive in areas of low productivity. Gemsbok prefer stony plains with at least limited water access, but can subsist in areas of dunes, rocky mountainous areas, and arid habitats with little seasonal water. Gemsbok also frequent open areas more than areas with increased tree density.
Range elevation: 900 to 1200 m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: desert or dune ; savanna or grassland
The range of gemsbok, Oryx gazella, mostly consists of southern east Africa, though formerly the range included South Africa.
Gemsbok have been introduced into Mexico, as well as the southwestern United States.
Biogeographic Regions: nearctic (Introduced ); ethiopian (Native )
Although generally a grazer, O. gazella will revert to browsing during droughts or whenever grasses are not available. These animals will also dig up to a meter to find tubers and roots. These, supplemented with wild tsama melons and cucumbers, provide all the water needed to sustain gemsbok (approximately three liters per 100 kg daily).
The dentition is highly adapted to cutting coarse desert grasses short, with high crowned molars and a wide incisor row. Desert dwellers can eat dry grass, but prefer green grasses. Activity at dawn and dusk allow for the consumption of the condensation present on the grasses.
Plant Foods: leaves; roots and tubers; wood, bark, or stems; fruit
Primary Diet: herbivore (Folivore )
Gemsbok are thought to have evolved reduced sexual dimorphism to facilitate longer acceptance of juvenile male presence by the territorial males.
Gemsbok are able to increase their body temperature to 45 degrees from 35.7 degrees C in order to delay evaporative cooling.
The species has been recognized since 1758.
There are seven identified subspecies, but none of them have been formally recognized yet.
Communication is particularly evident through dominance displays and aggressive behaviors. However, more subtle communication is conveyed by scent glands in the hooves, as well as urine sampling (primarily used to determine fertility). The animals have excellent hearing and smell, accounting for the prominence of stripe displays and scent marking. Although not specifically reported for these animals, as mammals it is likely that they use some accoustic means of communication. Tactile communication is also likely to play a role in reproductive activities.
Communication Channels: visual ; tactile ; acoustic ; chemical
Other Communication Modes: scent marks
Perception Channels: visual ; tactile ; acoustic ; chemical
The current total population of gemsbok is around 275,000 individuals. Though the numbers do not indicate a threatened population, large declines in several areas have resulted from livestock overgrazing, human encroachment on land, climate change, and habitat destruction. Other gemsbok populations have been declining due to over hunting.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
There are no negative economic impacts of this species on humans.
Gemsbok are hunted for their thick skin, which is used for shield covers by local African peoples. The horns are also used in making spears.
This species is a common game ranch species since both females and males have horns, making trophies cheaper to produce.
Positive Impacts: food ; body parts are source of valuable material
Gemsbok exploit areas that few other animals can inhabit; they tend not to interact with many other species. Also, because they are nomadic, they tend not to overgraze areas.
In regions of the North American Southwest where gemsbok (and other exotic species) have been introduced, overgrazing has occurred, leading to the degradation of the areas populated by these herds.
Ecosystem Impact: biodegradation
Commensal/Parasitic Species:
Gemsbok are polygynous. The resident bull of the herd mates with receptive females. Solitary territorial males are known to attempt to herd mixed or nursery herds onto their territories, thereby securing exclusive mating access to the females.
Mating System: polygynous
There is not a specific breeding season for gemsbok, though young within a herd tend to be of similar ages, indicating a reproductive synchrony in females. Females become sexually mature at about 2 years of age, and can conceive almost immediately after an 8.5 month gestation. Gemsbok are classified as "hiders", meaning the young are not seen present with the mother, but are hidden in the general vicinity, with the mother returning to nurse the calf 2 to 3 times each day. The young weigh between 9 and 15 kg at birth. At birth, calves are entirely brown in color. They develop the characteristic markings at about 3.5 months. At this point, the young are weaned. The males disperse and females join the maternal herd about a month after weaning.
Breeding interval: Gemsbok tend to breed every 9 months, and usually with little time between giving birth and becoming pregnant again.
Breeding season: Breeding season is year round, pending water availability.
Range number of offspring: 1 to 2.
Average number of offspring: 1.
Average gestation period: 8.5 months.
Average weaning age: 3.5 months.
Average time to independence: 4.5 months.
Range age at sexual or reproductive maturity (female): 1.5 to 2 years.
Average age at sexual or reproductive maturity (female): 2 years.
Range age at sexual or reproductive maturity (male): 1.5 to 2 years.
Average age at sexual or reproductive maturity (male): 2 years.
Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; post-partum estrous
Average birth mass: 12000 g.
Average gestation period: 270 days.
Average number of offspring: 1.
Like most ungulates, pregnant gemsbok isolate themselves from the herd before calving. The single neonate is kept concealed, usually within sight of the mother. This hiding behavior continues up to six weeks of age, ending with reconciliation with the herd.
Males are not reported to participate directly in parental care, so the feeding, sheltering, protection, and grooming of the young are all accomplished by the mother. As is the case with most bovids, the young are able to stand shortly after birth, and can move around with the mother as needed.
Parental Investment: precocial ; 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
Oryx gazella (common name Gemsbok) is a large antelope distributed in southwestern Africa, whose range has been considerably diminished (a) in the country of South Africa due to human overpopulation, habitat destruction and overhunting; and in (b) southern Angola from destabilizing warfare which occurred in the latter part of the twentieth century when Russia and Cuba sent in large numbers of troops in an attempt to destabilise the region.
This species is well adapted to the harsh arid and semi-arid environments of the region, with morphological dentition features enabling both grazing and browsing, and remarkable thermo-regulatory physiology that prevents dehydration in these environments. The total population of O. gazella is estimated at approximately 370,000 individuals.
Distribution and subspecies
Native distribution includes the majority of Namibia and Botswana, along with vestigial populations in southwest Angola and extreme northwestern South Africa. The range was much more extensive in western South Africa and southern Angola even one century ago. The human population explosion in South Africa, with attendant habitat destruction, overhunting and habitat fragmentation has decimated most of the native population in that country. In Angola, more recent warfare surrounding the Russian financed Cuban mercenaries, with attendant neglect of wildlife conservation in the latter part of the twentieth century has created considerable species decline.
The majority of the native range is populated by O. gazella gazella, the Kalahari gemsbok; however, the Angolan population is generally considered to be the subspecies O. gazella blainei, the Angolan gemsbok.
There are non trivial introduced populations of O. gazella in western Zimbabwe (Wilson & Reeder. 1993) and in the White Sands Missile Range, New Mexico in the USA.
Morphology
Oryx gazella is a sizable bovid exhibiting a thick, muscular neck, overlain by dense, inelastic skin. O. gazella is, in fact, the most massive species within the genus Oryx. This antelope stands 1.15 to 1.25 meters high at the shoulder, and presents a tail to nose tip body length of 1.80 and 1.95 meters, with males being slightly larger than females. The female body mass ranges from about 178 to 225 kilograms, while the male body mass is from approximately 180 and 240 kilograms.
Gemsboks have the ability to increase their internal body temperature as high as 45 degrees Celsius, as a mechanism to cope with high environmental temperatures and as a means of coping with evaporative water loss in its arid habitats. Tissues in its large nose present a means of cooling this large animal, by exposing a large area of veined tissue to the surrounding air.
The dentition of O. gazella is well adapted to cropping the short tough desert grasses, with a wide row of incisors and high crowned molars. (Archer & Sanson. 2002)
Habitat
Preferred habitat for this antelope is semi-arid and arid desert, bushveldt and grassland, including harsh environments of the Kalahari and Namib Deserts. (World Wildlife Fund & Hogan. 2012) O. gazella may be found on stony plains, sand dunes, rocky slopes and alkaline flats. It may travel considerable distances to drink from springs and visit natural salt deposits or salt licks. The typical altitude range of this species is from approximately 800 to 1300 meters above sea level.
This herbivore chiefly consumes its food by grazing, but during the dry season their palette is broadened to include a greater fraction of browse vegetation such as acacia pods. Adapting to arid environments has involved the ability to consume water rich foods such as bulbs, roots, tubers and tsama melons. (Sponheimer et al. 2003) The subsurface varieties of these foods it acquires by skillful excavation. (SSC Antelope Specialist Group. 2008)
The gemsbok or South African oryx (Oryx gazella) is a large antelope in the genus Oryx. It is native to the extremely dry, arid regions of Southern Africa; notably, the Kalahari and Namib Desert. Some authorities formerly classified the East African oryx (Oryx beisa) as a subspecies.
The name gemsbok is from Afrikaans, which itself is from the Dutch word of the same spelling, meaning "male chamois", composed of gems (“chamois”) + bok (“buck, male goat”).[4] The Dutch gems is further from German Gämse ("chamois").[5] Although some superficial similarities in appearance (especially in the facial pattern) are noticed, the chamois and the oryx are not closely related. The usual pronunciation in English is /ˈɡɛmzbɒk/.[6]
Gemsbok are light taupe to tan in color, with lighter patches toward the bottom rear of the rump. Their tails are long and black in color. A blackish stripe extends from the chin down the lower edge of the neck, through the juncture of the shoulder and leg along the lower flank of each side to the blackish section of the rear leg. They have muscular necks and shoulders, and their legs have white 'socks' with a black patch on the front of both the front legs, and both sexes have long, straight horns. Comparably, the East African oryx lacks a dark patch at the base of the tail, has less black on the legs (none on the hindlegs), and less black on the lower flanks. One very rare color morph is the "golden oryx", in which the gemsbok's black markings are muted and appear to be golden.
Gemsbok are the largest species in the genus Oryx. They stand about 1.2 m (4 ft) at the shoulder.[7][8] The body length can vary from 190 to 240 cm (75 to 94 in) and the tail measures 45 to 90 cm (18 to 35 in).[9] Male gemsbok can weigh between 180 and 240 kg (400 and 530 lb), while females weigh 100–210 kg (220–460 lb).
Gemsbok are widely hunted for their spectacular horns that average 85 cm (33 in) in length. From a distance, the only outward difference between males and females is their horns, and many hunters mistake females for males each year. In males horns tend to be thicker with larger bases. Females have slightly longer, thinner horns.
Female gemsbok use their horns to defend themselves and their offspring from predators, while males primarily use their horns to defend their territories from other males.[10]
Gemsbok are one of the few antelope species where female trophies are sometimes more desirable than male ones. A gemsbok horn can be fashioned into a natural trumpet and, according to some authorities, can be used as a shofar.[11]
Gemsbok are found in arid and semi-arid bushlands in southwestern Africa, especially around the Namib and Kalahari deserts, in Botswana, Zimbabwe, Namibia, South Africa and formerly Angola (where they are considered extirpated).[1]
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Gemsbok live in herds of about 10–40 animals, which consist of a dominant male, a few nondominant males, and females. They are mainly desert-dwelling and do not depend on drinking water to supply their physiological needs. They can reach running speeds of up to 60 km/h (37 mph). Gemsbok are mostly crepuscular in nature, since temperatures are tolerable and predator detection rates are highest during these times.
The gemsbok is generally a grazer but changes to browsing during the dry season or when grass is sparse. It may dig up to a meter deep to find roots and tubers, supplementing its water intake by eating wild tsamma melons and cucumbers, which can provide all the water required (3 liters per 100 kg bodyweight and day).[12]
The gemsbok is polygynous, with one resident male mating with the receptive females in the herd. The male is known to secure exclusive mating access to the females by attempting to herd mixed or nursery herds onto his territory. The gemsbok has no specified breeding season, but the young in a given herd tend to be of a similar age due to reproductive synchrony between females. Pregnant females leave the herd before giving birth. The gestation period lasts 270 days and mothers give birth to 1–2 offspring. The calf remains hidden 6 weeks after birth, after which mother and calf rejoin the herd. The calf is weaned at 3+1⁄2 months, becomes independent at 4+1⁄2 months, and achieves sexual maturity at 1+1⁄2–2 years in both sexes.[12]
In 1969, the New Mexico State Department of Game and Fish decided to introduce gemsbok to the Tularosa Basin, New Mexico, in the United States.[13] Ninety-three were released from 1969 to 1977, with the current population estimated to be around 3,000 individuals.[14] Gradually expanding their range from Tularosa Basin towards the west and northwest, an unknown number of animals are now also established in the San Andres National Wildlife Refuge, the Jornada Biosphere Reserve as well as the endorheic drainage basins east of Caballo Mountains, especially where these are traversed by the Jornada del Muerto trail north of Upham.
The inherent biology of gemsbok makes them a potential invasive species in New Mexico. As they are capable of year-round breeding, the transplanted population thrives in the presence of absence of their natural predators, such as the lion (Panthera leo), spotted hyena (Crocuta crocuta), cheetah (Acinonyx jubatus) and leopard (Panthera pardus). Except for calves, the oryx is too large to be preyed on by the coyote (Canis latrans) and most other major American desert carnivores, since the jaguar (Panthera onca) is mostly extirpated from the state, and the reintroduced Mexican wolf (Canis lupus baileyi) is too low in population numbers (and all known Mexican wolf populations are over 100 miles away). The species is therefore primarily managed by regulated hunting.[15][16] However, the only North American predator that regularly takes gemsbok is the cougar (Puma concolor); for only one individual, 29 gemsbok were hunted, with the species making up 58% of recorded kills (most consisting of newborns, but some adults were also shown to have been killed).[17]
Additionally, New Mexico gemsbok seem to prefer undisturbed grasslands for feeding, putting pressure on grassland ecosystems already threatened by climate change and encroachment by shrubs. This fact, along with their larger size and potentially dangerous horns, may cause them to outcompete with and/or put pressure on not only local livestock operations, but native desert herbivores, such as the pronghorn (Antilocapra americana) and the mule deer (Odocoileus hemionus). In addition, gemsbok may spread disease to fellow bovids like the desert bighorn sheep (Ovis canadensis nelsoni).[17]
The gemsbok is depicted on the coat of arms of Namibia,[18] where the current population of the species is estimated at 373,000 individuals.[1] In the town of Oranjemund, resident gemsbok wander freely around the streets, taking advantage of the vegetation in the town, such as the grass in parks, road medians, and browsing on low branches of the many trees.
The gemsbok or South African oryx (Oryx gazella) is a large antelope in the genus Oryx. It is native to the extremely dry, arid regions of Southern Africa; notably, the Kalahari and Namib Desert. Some authorities formerly classified the East African oryx (Oryx beisa) as a subspecies.
