Scimitar oryx

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Scimitar oryx
Adult at the Taronga Zoo
CITES Appendix I (CITES)[1]
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Bovidae
Subfamily: Hippotraginae
Genus: Oryx
Species:
O. dammah
Binomial name
Oryx dammah
(Cretzschmar, 1827)
Osteological specimen of a scimitar oryx in the Natural Science Research Laboratory's (NSRL) collection at the Museum of Texas Tech University.

The scimitar oryx (Oryx dammah), also known as the scimitar-horned oryx and the Sahara oryx, is an Oryx species that was once widespread across North Africa. In 2000, it was declared extinct in the wild on the IUCN Red List. This particular oryx is adapted to harsh desert conditions and can survive for months or even years without drinking water. A grazing animal, it derives most of its daily moisture intake from plants.

The decline of the scimitar oryx population began as a result of climate change during the

reintroduction program was launched and currently a small herd has been successfully reintroduced in Chad.[2]

The scimitar oryx was the emblem of the ancient Egyptian Oryx nome and today is the animal symbol of the Sahara Conservation Fund.

Taxonomy and naming

The scimitar oryx is a member of the genus Oryx and the family Bovidae. German naturalist Lorenz Oken first described it in 1816, naming it Oryx algazel. The nomenclature has undergone various changes since then, with the introduction of names such as Oryx tao, O. leucoryx, O. damma, O. dammah, O. bezoarticus, and O. ensicornis. In 1826, Philipp Jakob Cretzschmar used the name Oryx ammah for the species. A year later, the name Oryx leucoryx came into use, but as this was a synonym of the Arabian oryx (then called Oryx beatrix), it was abandoned, and Oryx algazel was accepted once more. Over 100 years later in 1951, Sir John Ellerman and Terence Morrison-Scott found that the name Oryx algazel was also ineligible for use. Finally, in January 1956, the International Trust for Zoological Nomenclature accepted Oryx dammah as the scientific name. No more changes have been made since then, though many papers published after 1956 created confusion by using names such as O. gazella tao.[3]

Its scientific name, Oryx dammah, is derived from: Ancient Greek ὄρυξ (orux), meaning a gazelle or antelope (originally a pickaxe[4]); Latin damma (fallow deer or antelope); and Arabic dammar (sheep).[5] The scimitar oryx is named for its horns,[6] which resemble scimitars.[5] Its common name in English is "scimitar-horned oryx", or simply "scimitar oryx".[3]

Genetics and evolution

Scimitar oryx at Chester Zoo

The scimitar oryx has 58

acrocentric autosomal pairs. The X and Y chromosomes are the largest and smallest acrocentrics.[7] The first molecular study of this species (published in 2007) observed genetic diversity among European, North American, and some other captive groups. Divergence was found within the mitochondrial DNA haplotypes, and was estimated to have taken place between 2.1 and 2.7 million years ago. Population increases occurred about 1.2 and 0.5 million years ago.[8]

In another study, intended to note genetic differences between Oryx species,

Bos taurus. The number of autosomes in all karyotypes was 58. The X and Y chromosomes were conserved in all five species.[9]

Physical description

Scimitar oryx in the Werribee Open Range Zoo, Victoria, Australia

The scimitar oryx is a straight-horned antelope that stands just over 1 m (3.3 ft) at the shoulder. The males weigh 140–210 kg (310–460 lb) and the females 91–140 kg (201–309 lb).[10] The body measures 140–240 cm (55–94 in) from the head to the base of the tail. The tail is 45–60 cm (18–24 in) long and ends with a tuft. They are sexually dimorphic with males being larger than females.[11]

Its

coat is white with a red-brown chest and black markings on the forehead and down the length of the nose.[5] The coat reflects the sun's rays, while the black portions and the tip of the tongue provide protection against sunburn.[12][13] The white coat helps to reflect the heat of the desert.[14] Calves are born with yellow coats and lack distinguishing marks, which appear later in life.[15] Their pelage changes to adult coloration at 3–12 months old.[12]

Both male and female oryxes have horns, with the females' being more slender.

Smithsonian National Zoo, a female oryx died at 21, an exceptional age since females generally have a lifespan of about 15 years.[17]

Diseases and parasites

The scimitar oryx can be infected with

Oocysts of a new parasite, Eimeria oryxae, have been discovered in the feces of a scimitar oryx from Zoo Garden in Riyadh.[20] In France, Streptococcus uberis was isolated for the first time in an oryx. It had caused vegetative endocarditis in the animal, leading to fatal congestive heart failure.[21]


Ecology and behavior

The scimitar oryx was a very sociable animal and traveled in herds of two to 40 individuals, generally, led by a

dominant bull. This species once gathered in groups of several thousand for migration. During the wet season, they migrated north into the Sahara.[15] Scimitar oryx are diurnal. In the cool early mornings and evenings, they rest under trees and shrubs, or if neither is available, they dig depressions in the soil with their hooves and rest there. Males fight often, but not for long and not violently. Predators, such as lions, leopards, hyenas, cheetahs, golden jackals, vultures, and Cape hunting dogs, mostly kill weak and young oryx.[3][5]

Adaptations

Captive scimitar oryxes grazing in a paddock, Marwell Zoo, Hampshire, UK

With a metabolism that functions at the high temperatures prevalent in their habitats, scimitar oryxes need less water for evaporation to help conduct heat away from the body, enabling them to go for long periods without water. They can allow their body temperatures to rise to almost 46.5 °C (115.7 °F) before beginning to perspire.[6] In times of ample supply, oryx can use fluid loss through urination and feces to lower their body temperatures to below 36 °C (97 °F) at night, giving more time before reaching maximum body temperature the following day.[15] They can tolerate high temperatures that would be lethal to most mammals. They have a network of fine blood vessels that carries blood from the heart to the brain, passing close to the nasal passage, thus allowing the blood to cool by up to 3 °C (5 °F) before reaching the brain, which is one of the more heat-sensitive organs of the body.[14][15]

Diet

The habitat of the scimitar oryx in the wild was steppe and desert, where they ate foliage, grass, herbs, shrubs, succulent plants, legumes, juicy roots, buds, and fruit.

Cassia italica, and Cornulaca monacantha.[3]

Reproduction

A young scimitar oryx
A young scimitar oryx with its mother

Both males and females reach

polyestrous.[22]

Courting is done by means of a mating circle; the male and female stand parallel to one another, facing in opposite directions, and then circle around each other until the female allows the male to mount from behind. If the female is not ready to mate, she runs away and circles in the reverse direction.

postpartum estrus; thus, they can produce one calf a year.[12] Gestation lasts about nine months, after which a single calf is born, weighing 10–15 kg (22–33 lb).[15] Twin births are very rare - only 0.7% of the births observed in one study. Both mother and calf return to the main herd within hours of the birth.[5] The female separates herself from the herd for a few hours while she nurses the calf. Weaning starts at 3.5 months, and the young become fully independent around 14 weeks old.[6]

Habitat and distribution

The scimitar oryx once inhabited grassy steppes, semideserts[15] and deserts in a narrow strip of central north Africa (especially in Niger and Chad).[6] It was widespread on the fringes of the Sahara, mainly in subdesert steppe, the grassy zone between the real desert and the Sahel, an area characterized by an annual rainfall of 75–150 mm (3.0–5.9 in). In 1936, a single herd of 10,000 scimitar oryxes was seen in the steppe area of Chad. By the mid-1970s, Chad was home to more than 95% of the world population of this species.[23]

Status and conservation

A group of scimitar oryxes at the Marwell Zoo in Hampshire, Great Britain

Following the

Neolithic Subpluvial, around 7500 to 3500 BC, the "green Sahara" became dry and the scimitar oryx's population began to decline due to a loss of suitable habitat. This was further exacerbated by humans who hunted the scimitar oryx for both its meat and horns. The northern population was already almost lost before the 20th century. With the introduction of horses and firearms during the 20th century, nomadic hunters were able to decimate populations.[24] The decline of the southern population accelerated as Europeans began to settle the area and hunt them for meat, hides, and horn trophies. French involvement in World War II[24] and the civil war in Chad that started in the 1960s are thought to have caused heavy decreases of the species through an increase in hunting for food.[6][25] Roadkill, nomadic settlements near watering holes (the oryx's dry-season feeding places), and introduction of cattle and firearms for easy hunting have also reduced numbers.[24][26]

The IUCN lists the scimitar oryx as extirpated in Algeria, Burkina Faso, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Nigeria, Senegal, Sudan, Tunisia, and Western Sahara, and has assessed it as extinct in the wild since 2000. Reports of sightings in Chad and Niger remain unsubstantiated, despite extensive surveys carried out throughout Chad and Niger from 2001 to 2004 in an effort to detect antelopes in the Sahel and the Sahara. At least until 1985, 500 scimitar oryxes were estimated to be surviving in Chad and Niger, but by 1988, only a few individuals survived in the wild.[1]

A global captive-breeding program now exists for the scimitar oryx.

Guembeul Wildlife Reserve (1999) in Senegal.[1]

Chad is currently leading a project to reintroduce the species in

reintroduced into the wild. An additional 21 individuals were released into the acclimation enclosure in 2017. The first ones to be relocated were released into the wild in 2016 and have adapted well to their surroundings. In 2017, another herd of 75 scimitar-horned oryxes arrived in an operation led by Chad's Ministry of Environment and Fisheries and the Sahara Conservation Fund
. In 2021, 60 new calves were born, bringing the number in the wild to about 400.

The Marwell Zoo in Hampshire and the Edinburgh Zoo have also worked in partnership with ZSL to help reintroduce captive-bred scimitar oryx to their former natural ranges.[32] The Tunisian reintroductions began in 1985 with 10 scimitar oryx from the Marwell and Edinburgh Zoos (co-ordinated by ZSL). In 1999 and 2007, Marwell co-ordinated the release of scimitar oryx into three more protected areas within their former historic range.

In culture

Woodcut illustration of a unicorn, from The History of Four-footed Beasts and Serpents by Edward Topsell

Ancient times

In ancient Egypt, scimitar oryxes were domesticated

Rio de Oro sent 1,000 shields made of it to a contemporary in the Middle Ages. Since then, it has been used to make ropes, harnesses, and saddlery.[3]

Unicorn myth

The myth of the one-horned unicorn may have originated from sightings of injured scimitar oryxes; Aristotle and Pliny the Elder held that the oryx was the unicorn's "prototype".[33] From certain angles, the oryx may seem to have one horn rather than two,[34][35] and given that its horns are made from hollow bone that cannot be regrown, if a scimitar oryx were to lose one of its horns, for the rest of its life it would have only one.[33]

Modern times

In 2015, Yellow Nose, a scimitar oryx that lives in Portland, Oregon, escaped and startled hikers in Forest Park.[36] The following day, he was caught and returned home.[37]

References

  1. ^ . Retrieved 16 January 2022.
  2. ^ a b "EAD successfully reintroduces 25 Scimitar Horned Oryx in Chad". Archived from the original on 2016-04-25.
  3. ^
    ISBN 978-0-9521397-2-0. Archived from the original
    (PDF) on 2016-08-04.
  4. ^ Harper, Douglas. "oryx". Online Etymology Dictionary. Retrieved 2013-02-21.
  5. ^ a b c d e f g h i Huffman, B. "Oryx dammah (Scimitar-horned oryx)". Ultimate Ungulate.
  6. ^ a b c d e f "Scimitar-horned oryx (Oryx dammah)". ARKive. Archived from the original on 2008-10-26.
  7. PMID 8206781
    .
  8. .
  9. .
  10. .
  11. .
  12. ^ a b c "Scimitar-horned Oryx (Oryx dammah)". World Association of Zoos and Aquariums (WAZA).
  13. ^ a b "Oryx dammah" (PDF). Sahelo-Saharan Megafauna. Sahelo-Saharan Antelopes.
  14. ^ a b c "Scimitar-horned Oryx". National Zoological Park.
  15. ^ a b c d e f g h i Johnson, H. "Oryx dammah". University of Michigan Museum of Zoology. Animal Diversity Web.
  16. ^ a b "Scimitar-horned oryx". Safari West.
  17. ^ Zoon, J. (22 March 2012). "Elderly Oryx Dies at Smithsonian's National Zoo". Smithsonian Newsdesk. Retrieved 15 October 2012.
  18. PMID 15567578
    .
  19. .
  20. .
  21. .
  22. .
  23. .
  24. ^ .
  25. ^ "Oryx dammah (O. tao)". Animal Info.
  26. .
  27. (PDF) on 2016-04-16. Retrieved 2016-01-25.
  28. .
  29. ^ "SCF Oryx Project receives strong presidential support – SCF – Sahara Conservation Fund". Sahara Conservation Fund. Archived from the original on 2016-04-15.
  30. ^ Technical Workshop on the Reintroduction of Scimitar-horned Oryx to the Ouadi Rimé-Ouadi Achim Game Reserve, Chad, May 2–4, 2012. Sahara Conservation Fund.
  31. ^ a b c "Scimitar-horned oryx returns to Sahara". Zoological Society of London (ZSL). 14 February 2017. Retrieved 28 February 2017.
  32. ^ "Days out in Hampshire | Family day out near me".
  33. ^ .
  34. ^ "Arabian Oryx". Natural History Museum of Los Angeles County. Archived from the original on 2007-10-10. Retrieved 2008-01-25.
  35. .
  36. ^ Hammond, B. (2015). "An elk? An oryx? Large, unusual-looking horned animal reported on Germantown Road in Forest Park". The Oregonian.
  37. ^ Mayes, S. (2015). "Yellow Nose, the oryx wandering Northwest Portland's Forest Park, has been caught". The Oregonian.

External links