
Physical Characteristics
The Oryx is a large antelope with long, spear-like horns. It is a true
desert animal. It has a thick, horse-like neck with a short mane and
a compact, muscular body. A defined pattern of black markings that
contrast with the white face and fawn-colored body are prominently
displayed in dominance rituals to emphasize the length of horns and
strength of the shoulder.
Kenya's Tana River divides the range of East Africa's two types of
Oryx the beisa Oryx (Oryx gazella beisa) and the fringe-eared Oryx
(Oryx gazella callotis). The fringe-eared Oryx ranges from Kenya to
central Tanzania. The beisa Oryx ranges from Ethiopia through
Somalia into northeastern Uganda and Kenya.
Habitation
Originally, various Oryx species were found in all of Africa's arid
regions. One species that occurred on the Arabian Peninsula was
exterminated recently but has now been reintroduced into the wild
from captive stock. Well adapted to the conditions of their hot and arid habitats,
Oryx can live as long as 20 years.
Behavior and Habits
The social system of the Oryx is unusual in that non-territorial
males live in mixed groups with females, or with females and their
young. Males that dominate are territorial to a certain degree, marking
their areas with dung deposits.
The dominance hierarchy among Oryx is based on age and size. As they
grow, calves assess one another in tests of strength that look like
games. As the hierarchy becomes established, the need to fight is
reduced. Ritual displays replace actual contact, except when evenly
matched individuals may have to fight to establish their rank. Along
with lateral displays, Oryx perform a slow, prancing walk and
sometimes break into a gallop. When several males are making these
displays, they may clash horns.
A female leaves the herd to give birth and hides the calf for 2 or 3
weeks, visiting a few times a day to nurse it. The newborn is an
inconspicuous brown color. The black markings begin to appear when
the calf is ready to return to herd with its mother. Calves are
suckled for 6 to 9 months and reach maturity at 18 to 24 months.
Most young males migrate out of their natal group to join other
groups.
Diet
Oryx typically feed in early morning and late afternoon. Their diet
mainly consists of coarse grass and browse from thorny shrubs. In
desert areas they consume thick leaved plants, wild melons, and
roots and tubers they dig out of the ground. Plants collect dew,
which is gradually released during the hotter parts of the day. Some
plants increase their water content by 25 to 40 percent, so when
Oryx feed late at night or early in the morning, they maximize both
food and water sources.
Predators and Threats
The tribesmen of Lake Turkana in North Eastern Kenya hunt Oryx for their meat and hides. In
many cultures, the horns of the Oryx are sought after as charms;
even in medieval England they were marketed as unicorn horns.
Thought You Should Know
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The Oryx is a good example of an antelope that has successfully
adapted to the harsh conditions of dispersed food, intense heat and
little or no water.
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The female comes into heat soon after giving birth. The more
frequent estrus cycles enable females to produce calves at 9 month
intervals.