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Gemsbok (Oryx)

Appearance
Bull: Shoulder height 120 cm; mass 240 kg; average horn length 85 cm
Cow: Shoulder height 120 cm; mass 210 kg; average horn length 85 cm
Heavily built with short, thick neck and distict black-and-white markings on the head, body and legs; has long, black horse-like tail. Body colour greyish-fawn, separated from white underparts by black streak along flanks. Black patches on upper part of legs and along top of rump. Black stripe runs down front of neck. Calves fawn and lack black body markings. Both sexes carry the long, almost straight, transversely ridged, rapier-like horns; Those of bull are shorter and more robust.
Habitat
Open, dry country but also open woodland, grassveld and dune country. Availability of water is not an essential habitat requirement.
Behaviour
Gregarious, occuring in herds of about 15. Somtimes in larger numbers, particularly during rains. They may occur in mixed herds (consisting of bulls, cows and young of different ages) or nursery herds (cows and young); solitary bulls are often seen. A territorial bull wil herd a mixed or nursery herd into his territory and only he will mate with receptive cows. Gemsbok are usually forced by the nature of their hostile environment to be nomadic, moving to fresh vegetation growth following rain.
Food
Although mainly grazers they also include browse, seed-pods and fruits in their diet.
Gemsbok have a lowered metabolism. This means they need a lot less to survive than for example the equally sized wildebeest. They can extract all the moisture they need de water-rich tsamma melons and subterranean taproots. They can survive indefinately without drinking.
Interesting links
Wikipedia