Oryx gallarum (Neumann, 1902)

Don E. Wilson & Russell A. Mittermeier, 2011, Bovidae, Handbook of the Mammals of the World – Volume 2 Hoofed Mammals, Barcelona: Lynx Edicions, pp. 444-779 : 645

139.

Galla Oryx

Oryx gallarum

French: Oryx d'Ethiopie / German: Galla-Oryx / Spanish: Oryx de Etiopia

Taxonomy. Oryx beisa gallarum Neumann, 1902 ,

Orte Balinga, Modjo, southern Ennia-Gallaland, near the Webi, Ethiopia.

The Galla Oryx was formerly considered a subspecies of O. beisa . Monotypic.

Distribution. N Kenya (approximately N of the Tana River and in the Lake Turkana district) and NE Uganda (Karamoja region); its range presumably extends an unknown distance into Somalia and SE Ethiopia.

Descriptive notes. Head-body 169 cm, tail 46 cm; hindfoot 51 cm; weight 181 kg (one male). The color is paler, purer gray than in the typical Beisa Oryx ( O. beisa ), and this color extends below the black flank band, which is therefore not a boundary between the body color and the white underside. The face is paler than the neck, sometimes even whitish. The facial and gorge bands are separated, but sometimes the two nasal bands are joined, and the nose streak is diffuse. The legs are white, with only a trace of stripes. The flank band width measures 20-44 mm, so narrower on average than in the Beisa Oryx , and the dorsal stripe is also fairly narrow, measuring 30-43 mm, and is generally very vaguely expressed and occasionally absent. The horns are slightly shorter than in the Beisa Oryx , 65-86 cm long, but the same shape and thickness, 9.5-12 cm at the base, and the tips are some 7.5-24 cm apart. The diploid chromosome numberis 58; chromosomes are different from those of the Gemsbok ( O. gazella ), and resemble those of the Fringe-eared Oryx ( O. callotis ). The mtDNA (control region and cytochrome b) sequences are strongly distinct from those of Fringe-eared Oryx . Dental formula is 10/3, C0/1,P 3/3, M'3/3 (2) = 32.

Habitat. Dry flat country, both grasslands and thorn scrub.

Food and Feeding. Mainly a grazer, but occasional browsing. They are independent of surface water, although they drink when it is available.

Breeding. Apparently year-round, but concentrated in the wet season. Gestation is 265-300 days, and calves are hiders.

Activity patterns. They seem to wander from place to place seasonally in large aggregations, moving to higher ground in the rains and back to lower ground in the dry season. The locomotory patterns are like those of the Beisa Oryx . They rest in the heat of the day, either standing or lying, usually under shade. The tail is constantly switching, whether the oryx is resting or feeding.

Movements, Home range and Social organization. Both small groups and herds of up to 50. Males have been reported to be solitary or in small groups.

Status and Conservation. Classified as Near Threatened on The IUCN Red List (under O. beisa ). The Galla Oryx is reported to be numerous in the Samburu region and elsewhere in northern Kenya.

Bibliography. Groves & Grubb (2011), IUCN/SSC Antelope Specialist Group (2008 aj), Kingdon (1982), Roosevelt & Heller (1914).

Figures

138. Beisa Oryx (Oryx beisa), 139. Galla Oryx (Oryx gallarum), 140. Fringe-eared Oryx (Oryx callotis), 141. Gemsbok (Oryx gazella), 142. Scimitar-horned Oryx (Oryx dammah), 143. Arabian Oryx (Oryx leucoryx)

Distribution. N Kenya (approximately N of the Tana River and in the Lake Turkana district) and NE Uganda (Karamoja region); its range presumably extends an unknown distance into Somalia and SE Ethiopia .