Oryx leucoryxArabian oryx

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Geographic Range

Oryx leucoryx were originally found in Syria, Iraq, Israel, Jordan, Sinai, and the Arabian Peninsula (Nowak, 1999; Wilson and Reeder, 1993).

Habitat

Usually O. leucoryx are found in arid plains and deserts, however they have also been found to inhabit rocky hillsides and thick brush. Their habitat according to Nowak (1999) consists of "flat and undulating gravel plains intersected by shallow wadis and depressions and the dunes edging sand deserts with a diverse vegetation of trees, shrubs, and grasses."

Physical Description

Head and body length of O. leucoryx varies from 1,530 to 2,350 mm. Tail length is 450-900 mm, and shoulder height is 900-1,400 mm. A mane extends from the head to the shoulders and the tail is tufted. Males also have a tuft of hair on the throat. Both sexes have horns ranging from 600-1,500 mm in length. They are fairly straight and are directed backwards from the eyes. The horns of females are usually longer and thinner than the horns of males. In general, the coloration of adults varies from cream to grays and browns and they may have striking markings of black and brown as well. The young are shades of brown and have markings only on their tails and knees (Nowak, 1999).

  • Range mass
    100 to 210 kg
    220.26 to 462.56 lb

Reproduction

Reproductive timing in O.leucoryx varies. However, in favorable conditions, a female can produce a calf once a year during any month. Most births among introduced herds in Oman and Jordan occur from October to May. Gestation period in this species is about 240 days. Young are weaned by 4.5 months, and captive females initially give birth at age 2.5-3.5 years. The potential longevity of these animals seems to be about 20 years (Nowak, 1999).

  • 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
    8 (low) months
  • Average gestation period
    8 months
  • Range weaning age
    4.5 (high) months
  • Average weaning age
    4.5 months
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    794 days
    AnAge
  • Parental Investment
  • post-independence association with parents

Lifespan/Longevity

  • Average lifespan
    Status: captivity
    20.8 years
    AnAge

Behavior

When O. leucoryx are not eating or wandering their habitat, they dig shallow depressions in the soft ground under shrubs and trees for resting. They are able to detect rainfall from a great distance and move in the direction of fresh plant growth. Since rainfall is irregular they must travel over hundreds of square kilometers in no set pattern.

An introduced herd of O. leucoryx in Oman was reported, in 1983, to use a range of about 3,000 sq. km, compromising a series of separate suitable areas about 100-300 sq. km in size, which were occupied for 1-18 months at a time. The population density was 0.35/sq. km.

In 1993, it was noted that the occupied area of Oman had grown to 14,121 sq. km and contained 18 breeding herds, with a mean size of 5.8 individuals and a mean range of 57 sq. km. In addition, there were 10 solitary bulls with largely separate territories of 44-453 sq. km and a small bachelor herd.

Oryx are gregarious. Their normal group size is 10 animals or fewer, but as many as 100 individuals have been seen in one herd. Captive O. leucoryx have been maintained in herds consisting of a single dominant adult male and several adult females and young. Groups of bachelors are kept separately and establish a hierarchy amongst themselves through fighting and chases.

Oryx have been described as alert, wary, and keen sighted. They defend themselves by lowering their head so that their sharp horns point forward.

Communication and Perception

Food Habits

O. leucoryx feed on diverse types of grasses and shrubs found in their arid habitat. They go to streams and water holes to drink. When free water is not available, they can obtain moisture from sources such as melons and succulent bulbs which is sufficient for lengthy periods of time.

An introduced herd of O. leucoryx in Jordan was observed to have become active just after dawn, they grazed until about 1000hrs, rested from 1400hrs to 1500hrs, grazed again, then began to move toward a sleeping area around sunset (Nowak, 1999).

Economic Importance for Humans: Positive

O. leucoryx have many positive benefits for humans. The meat is greatly appreciated, their hides are valued for leather, and other parts have alleged medicinal uses. The head is also highly valued as a trophy (Nowak, 1999).

  • Positive Impacts
  • food
  • body parts are source of valuable material

Economic Importance for Humans: Negative

These animals could cause a negative effect on humans if their habitats overlap as oryx may consume crop plants. However, historically this has not been the case (Nowak, 1999).

Conservation Status

O. leucoryx is also classified as endangered by the USDI.

The last known individuals in the wild were killed in 1972, and there are unconfirmed reports from as late as 1979. However, in the 1950's efforts were made in several Arabian countries to establish captive herds. In 1962, some Arabian oryx were taken from the wild and were brought to the U.S. These animals served as the foundation of an international breeding effort and for reintroductions into the wild in Oman in 1982, Jordan in 1983, and central Saudi Arabia in 1990. There are now approximately 500 individuals in the wild, 300 in captivity on the Arabian Peninsula, and 2,000 held elsewhere (such as the Phoenix and San Diego zoos). Despite the former severe reduction of the species, its current genetic variability is considered normal (Nowak, 1999; Wilson and Reeder, 1993; Burton, 1987).

Other Comments

Oryx leucoryx are also known as Arabian oryx (Nowak, 1999).

Contributors

Heather Leu (author), University of Michigan-Ann Arbor, Phil Myers (editor), Museum of Zoology, University of Michigan-Ann Arbor.

Glossary

Ethiopian

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

World Map

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.

chaparral

Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.

chemical

uses smells or other chemicals to communicate

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

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

social

associates with others of its species; forms social groups.

solitary

lives alone

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

Burton, J. 1987. The Collins Guide to the Rare Mammals of the World. Massachusetts: The Stephen Greene Press.

Nowak, R. 1999. Walker’s Mammals of the World. Baltimore and London: The John Hopkins University Press, Vol II, 6th edition.

Wilson, D., D. Reeder. 1993. Mammal Species of the World: A Taxonomic and Geographic Reference. Washington and London: Smithsonian Institution Press, 2nd edition.