Africa is home to 72 out of 84 antelope species alive today. Antelopes are critical for these biomes because they are a major part of the food chain. They eat the vegetation available and are hunted by the top predators. Each species is adapted to live successfully in its environment. Antelope belong to the bovid family, which also includes buffalo, cattle, sheep, and goats. All antelope are herbivores (plant eaters), even-toed ungulates (hoofed animals), and ruminants (animals with four-chambered stomachs that chew a cud – in other words regurgitated food that is re-chewed as part of the digestive process).
You will note that many antelope’s ranges are not restricted to one specific biome. These animals are adapted to live in multiple biomes.
In this activity, students explore Africa’s biomes using range maps of different antelope species to see where they live. After this discovery, the students hypothesize why there are so many different species of antelope in Africa.
Africa can be divided into seven major biomes: (1) desert (2) semi-desert; (3) steppe; (4) savanna; (5) tropical rainforest; (6) montane; and (7) Mediterranean (see Map of Africa’s Biomes).
The deserts of Africa stretch for 2,000 km (1,200 miles) along the southwest coast of Africa. The Namib is the world’s oldest desert and has existed for at least 80 million years. Temperatures there can rise over 49ºC (120ºF) and annual rainfall is less than 20 cm (8 inches) per year. This barren landscape of huge shifting sand dunes, gravelly plains and rugged mountains provides homes for hardy plants and animals adapted to survive the inhospitable conditions of the desert, such as the dik dik and the Hunter’s hartebeest.
The semi-desert biome lies between the desert biome and the steppe biomes. This transitional environment receives more rainfall than the desert, but less than the dry and moist savannas. The animals and plants living here have adapted to this in-between climate. Resembling the scrub environments of our Southwestern states like New Mexico and Arizona, prey animals living here are typically smaller in order to hide behind the short vegetation and are excellent at conserving water.
Like savannas, steppes are areas of open grassland with very few trees. Steppes, however are located in colder climate regions and receive less precipitation on average than savannas. Temperatures in temperate grasslands vary according to the season. In winter, temperatures can plummet to well below 0ºF in some areas. In summer, temperatures can reach above 90º. These temperate grasslands receive low to moderate precipitation per year (20-35 inches on average). Much of this precipitation may be in the form of snow. As in the savanna, seasonal drought and occasional fires are very important to biodiversity. However, their effects aren't as dramatic in temperate grasslands as they are in savannas. The soil of the steppe is deep and dark, with fertile upper layers. It is nutrient-rich from the growth and decay of deep, many-branched grass roots. The rotted roots hold the soil together and provide a food source for living plants. Each different species of grass grows best in a particular grassland environment (determined by temperature, rainfall, and soil conditions). The seasonal drought, occasional fires, and grazing by large mammals all prevent woody shrubs and trees from invading and becoming established.
Savannas cover much of central Africa and host more antelope species than any other biome. A savanna is a tropical or subtropical grassland containing scattered trees and drought-resistant undergrowth. The difference between dry and moist savannas lies in the average yearly rainfall. On average, the African Savanna receives about the same rainfall as that of Wisconsin. During the rainy season, beginning in May and ending in November, rainfall averages 15-25 inches per month. The dry season averages four inches of rain per month. The African savanna is so huge that it may be further divided into sub-biomes, such as the dry savanna, the moist savanna, the coastal savanna, and the acacia savanna.
The African dry savanna is a thorn bush and grass savanna that hosts many plant species, including various acacia species, candelabra trees, jackalberry trees, whistling thorn bushes, baobab trees, Bermuda grass, baobabs, and elephant grass. Much of the dry savanna, such as the Serengeti Plains, has very dry but nutrient-rich volcanic sand. Around 2 million large plant-eating mammals live in this biome. There are 45 species of mammals, almost 500 species of birds, and 55 species of acacia in the Serengeti Plains. There are animals such as lions, African wildcats, klipspringer, steenbok, Burchell's zebra, African savanna monitor, and puff adders. They have the largest diversity of hoofed animals in the world including antelopes, wildebeest, buffalos, zebras, and rhinoceros. Some animals are grazers, some are browsers, and some do a little of both. One herd of browsers nibbles at the trunk of a tree, another looks a little higher for food, a third eats even higher than the ones below them, and another herd browses at the very top.
This biome has been helped, hurt, and changed by humans in many ways. For example people use the land for cattle grazing (which kills the grass and turns the savanna into a desert), they cause many fires that destroy the land, use of wood for fuel also causes problems to the environment, and people also poach (hunt the animals illegally) which causes animals to become extinct.
Within moist savannas we find extensive flooded grasslands and wetlands that provide unique habitats for many African species. Black lechwe feed in marshy areas and will follow the river’s course in search of good feeding spots where vegetation is abundant. They are comfortable wading into water up to their shoulders and if threatened seek safety in deep water. Not far from this spot is the source of one of the world’s longest rivers, the mighty Congo, which traverses central Africa for nearly 6,400 km (4,000 miles).
The tropical rainforests of Africa are located around the equatorial region of the continent. These lush areas have high elevated slopes where misty cloud forests are found. Tropical forests have many species of broadleaf trees and a climate that can be wet or dry. Thick montane forests on East Africa’s high mountains provide protective cover for animals such as the shy and elusive bongo. These mountains rise in sharp contrast to the low elevation grasslands that surround them and the slopes are dominated by dense stands of bamboo. Like the bongo, many of the plants and animals here live nowhere else in the world.
The montane biome includes mountainous grasslands and shrublands primarily dispersed throughout the southern part of the continent. This biome supports some of the largest and most charismatic animals in Africa. Much of the wildlife in this area is protected in national parks and private reserves. Rainy summers produce abundant vegetation in montane woodlands, providing an important food source for animals such as roan and sable antelope.
The mediterranean biome is characterized by a climate with cool, wet winters and hot, dry summers. The Cape Floristic Province hugging the coastline of Southern Africa is located within Africa’s mediterranean biome, and is famous for hosting over 9,000 different kinds of plants, more that any other place in the world outside of the tropics. The landscape is dominated by fynbos (shrublands comprised of evergreen fire-dependent plants that thrive on rocky or sandy nutrient-poor soils) where one can spot steinbok feeding on grass, tubers, and leaves. Both the Cape Floristic Province and much of California are biodiversity hotspots and are among the world’s most threatened habitats, as over 70% of the original habitat has already been lost to agriculture and development.