the Bovid family
The Bovid Family (hollow-horned ruminants) includes 120 species, 84 of which are antelopes. Africa is home to 72 antelope species. Cattle, sheep, and goats originated in Eurasia and as a result, very few species were able to travel down beyond the Sahara Desert.
The diverse family of African bovids came into existence 24 million years ago and reached its evolutionary peak over the last several million years of the ice age.
Family Traits
Size
Bovids range in size from the largest antelopes, oxen and buffalos weighing over one ton to the 4 lb royal antelope.
Horns
All bovid males and 2/3 of females have horns. The horn consists of an outer shell covering an inner core of bone. In some cases the horns of the female are longer than those of the male. The texture and wear of horns, together with the sharpness, surface texture and width of groves, can indicate the age of the animal. Characteristically, younger bovids have sharp and smooth horns with fairly wide groves.
Color
The colors range from black to white, with brown being the most common color. Sociable species tend to have distinct markings which enable members of a herd to tell each other apart. Antelopes, which rely on camouflage, often have stripes or large blotches on their hides to protect them from predators.
Habitat
Wherever there is vegetation, from deserts to swamplands and lowland plains to high mountaintops, there are always antelopes ready to graze. Each species of African antelope has adapted to a particular environment based on size, feeding technique, digestive system, and social and reproductive systems. Inevitably, two or more species share the same areas and to some degree compete for territory and resources. In one case, over 12 different species of antelope have been spotted in one area.
Water Dependence & Independence
Antelopes that are water-independent have the freedom to explore vast areas, an advantage that water-dependent antelopes do not have. In most cases, pure grazers are water-dependent, which means that they must drink water every day or every two days. Browsers, however, can obtain their water needs by eating leaves, herbs, and other plants that store water.
Antelopes that live in dry areas have numerous strategies for minimizing the amount of water required. To avoid overheating, some rest in the shade during the heat of the day. Most antelopes feed during the coolest hours of the day when the vegetation has collected water from the air.
Some antelopes allow their body heat to rise by 10* F (6* C) and simply store the heat instead of panting or sweating which uses up a lot of energy.
An antelope's ability to adapt to dry conditions varies from tribe to tribe. This ability is not limited to desert species.
Social/Mating Systems
Whether or not antelopes live in herds or lead solitary lives depends solely on their environment. Generally speaking, antelopes must see each other in order to stay together. In most cases, the larger the habitat, the larger the herd. One will find the smallest herds where there are small patches of grass and the largest herds on expansive plains.
Bovid social/mating systems are either territorial or non-territorial, solitary or sociable.
-- Solitary/territorial: As both sexes age, they become territorial. Young tend to spend time alone travelling in small groups and interacting with each other. This way of life leads to an equal male/female ratio as they age.
--- Monogamous pair: Male and female mate for life. Each share and defend territory against intruders of the same gender. This is most common among: blue duiker, dik-diks, klipspringer, and dwarf antelopes.
--- Polygamy: One male mates with two or more females. Females live alone with offspring.
-- Sociable/territorial: Adult males are territorial while females share home range with other females. Non-territorial males heard together, as a result there is a higher male mortality rate which means that the female sex ratio is favored.
-- Sociable/non-territorial: Females share home range and herd with other females. Males compete for mating opportunities. A dominance hierarchy is based on size and seniority.
Reproduction
In all African antelopes there is only a single offspring. The gestation period is 4 to 6 months for small-to medium-sized antelopes and 8 or 9 months for larger species. Reproduction must take place while food is abundant. This means that antelopes that live in areas where food is always abundant can breed at any time throughout the year. Most antelopes live in areas where there is a 3 to 8 month dry season, so these antelopes adapt accordingly. Those living in equatorial regions, where there are 2 rainy and 2 dry seasons, reproduce twice each year.
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