Serengeti National Park, Tanzania Photograph by John Morrison   Afrotropics Tropical and Subtropical Grasslands, Savannas, and Shrublands   88,000 square miles (227,800 square kilometers) -- about the size of Mississippi and Ohio combined Vulnerable

· Under the Serengeti Sun
· Special Features
· Did You Know?
· Wild Side
· Cause for Concern
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Under the Serengeti Sun

Undoubtedly the world’s most spectacular migration of large mammals takes place in the heart of the Southern Acacia-Commiphora Bushland and Thicket ecoregion. Across wide-sweeping grasslands and associated woodlands dominated by species of acacia and commiphora trees, massive herds of wildebeest, plains zebras, and Thomson’s gazelles travel in search of food and water as they cross the Serengeti ecosystem. This ecoregion is very closely associated with the Serengeti Volcanic Grasslands ecoregion and also encompasses parts of Serengeti National Park and the Ngorongoro Conservation Area, both of which are World Heritage Sites and Biosphere Reserves.

Special Features

Life in the Southern Acacia-Cammiphora Bushland and Thicket ecoregion is strongly influenced by its seasonal climate, which can be unpredictable. Rains usually fall twice a year, with long periods of rain from March through May and short periods from November to December. However, the short rains may fail to come some years, or rain may occur in between the normal rainy seasons. During the long dry season, between August and October, the grasslands can become extremely dry, and many of the trees and bushes lose their leaves. Another important factor shaping life in this region is disease--or the lack of it. The tsetse fly, which carries sleeping sickness, was once present in the region, but its eradication has now made human settlement possible. And outbreaks of a fatal disease called rinderpest have caused large-scale deaths in both wild antelope and domestic cattle in the region from time to time.

	Throughout the region, elephants play an important role in converting dense thicket and bushland into grassland by knocking down whole trees to reach leafy crowns. An adult African elephant may eat as much as 300 pounds (136 kg) of food a day.

Wild Side

Following the patterns of rainfall in the area, vast migratory herds of wildebeest, plains zebras, and Thomson’s gazelles move through the landscape in a succession as they search for food and water. Hundreds of thousands of plains zebras begin grazing the coarse stalks of grass. They are soon followed by millions of wildebeest, which graze the smaller grass leaves and forbs that become more visible after the zebras’ mowing. The Thomson’s gazelles, with their smaller mouths, also graze the small tender new shoots. Hyenas, lions, and wild dogs in turn prey upon these herds. In woodland areas, a diversity of birds, reptiles, and small mammals includes the wedge-snouted worm lizard, a reptile found nowhere else on Earth.

Cause for Concern

Outside of protected areas, most of the land in this ecoregion has been converted to farms and livestock areas. These land uses make it incredibly difficult for large mammals to find their way among isolated islands of protected habitat. Furthermore, when migrating animals move outside of the protected areas, conflict with farmers is inevitable. Many woodland areas are also threatened by cutting of trees for making charcoal that is used for daily cooking needs and for drying the tobacco grown on farms. Of increasing concern is the illegal killing of animals for food, trophies, and even medicines. For example, in areas where people rely on bushmeat as a major source of protein, populations of ungulates have declined at alarming rates. Most black rhinoceroses in this region have already been killed by trophy hunters and poachers seeking their valuable horns.

For more information on this ecoregion, go to the World Wildlife Fund Scientific Report.