Oryx beisa (Rüppell, 1835)
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publication ID |
https://doi.org/ 10.5281/zenodo.6512484 |
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DOI |
https://doi.org/10.5281/zenodo.6636855 |
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persistent identifier |
https://treatment.plazi.org/id/03F50713-9901-FFBA-034C-FE1DFB1FF598 |
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treatment provided by |
Conny |
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scientific name |
Oryx beisa |
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Beisa Oryx
French: Oryx beisa / German: Beisa-Oryx / Spanish: Oryx beisa
Taxonomy. Antilope beisa Ruppell, 1835 ,
Red Sea coast west of Massawa, Eritrea.
There is some indication that the oryxes of the Awash Valley are somewhat different from those of the more desert areas. Usually, all East African oryxes have been placed in one species (and frequently even grouped as the same species as the Gemsbok, O. gazella, of south-western Africa), but actually there are consistent differences between populations, and they form three distinct species. Monotypic.
Distribution. N & C Somalia and the Ogaden region of Ethiopia, N to Berbera, W to Eritrea, and S into the Awash Valley. View Figure
Descriptive notes. There are no specific measurements available for this species, but it is said to be “about 4 feet ” (1-2 m) in shoulder height. As in all oryxes, the skin on the shoulders is extremely thick. The color is ocher-gray with a pinkish wash, and this color is bordered below by a black flank band that forms a boundary with the white belly. The face is colored like the body, with black bands through the eyes (usually as far as the corner of the mouth) and down the middle of the face; these facial bands generally join up with each other and with a similar band under the upper throat. There are no ear tufts. The flank band is 23-58 mm wide; there is a dorsalstripe measuring 24-71 mm in width, and this may extend up the neck, or for three-quarters of the length of the neck, or just to the withers. The horns are 74-90 cm long, 11-4 cm thick at the base, and the tips are about 18-8 cm apart; they have about 15-25 rings. The face of the form ofthis species found in the Awash Valley tends to be deeper ocher in color, and the legs tend to be paler. Horns are very long compared with the skull length. There is no information on the DNA ofthis species. Dental formula is 10/3, C 0/1, P3/3,M3/3 (x2)=32.
Habitat. Mainly desert country; in northern Somalia, on stony flats, on flat-topped desert hills, and in desert bush; in the Awash Valley, its habitat is open plains, shortgrass savanna, and thornscrub.
Food and Feeding. There is no specific information available for this species, butit may be assumed that its diet consists mostly of dry-desert vegetation and is independent of standing water.
Breeding. Male Beisa Oryxes , like Addaxes ( Addax nasomaculatus ), rest the chin on the female’s croup as a prelude to mounting, and the female responds in head-low posture with circling (characteristic of the tribe Hippotragini ). In mating, the male rears upright, firmly grasping the female’s loins.
Activity patterns. Beisa Oryxes amble, nodding their heads when walking fast, and have a flowing trot. They no doubt rest like other oryxes in the heat of the day, either standing or lying, usually under shade.
Movements, Home range and Social organization. There is no specific information available for this species, except that it is seen in small herds, up to 30 or more in the western part of northern Somalia and usually 7-12 on the stony hills near the Somali coast; occasional solitary individuals are seen.
Status and Conservation. Classified as Near Threatened on The IUCN Red List. The Beisa Oryx is reported to be common in the Awash National Park, but declining elsewhere, with threats from excessive hunting and overgrazing. Population declines likely approached 25% over the past three generations, reaching the threshold for classification as Vulnerable in the near future.
Bibliography. Estes (1991a, 1991b), Groves & Grubb (2011), IUCN/SSC Antelope Specialist Group (2008al).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
