Upper Nile Group
Permanent water in arid areas attracts species that require drinking water daily and also some adapted for semi-aquatic existence. Hippopotamuses (Hippopotamus amphibius) live in groups in water and can submerge for as long as 6 minutes. At night they leave to feed on as much as 130 pounds of grass. A single baby is born on land or in water after an 8-month gestation period and may live 45 years.
The rarely seen sitatunga (Tragelaphus speki), most aquatic of antelopes, sometimes submerges to its nostrils to hide. Extremely long hooves and flexible feet allow sitatungas to traverse mud and marsh without sinking. Sitatungas are mainly browsers, and the hornless females are brighter colored and more conspicuously marked than the males.
Waterbuck (Kobus ellipsiprymnus) live in herds of about twenty-five, always near water. Reaching 600 pounds in weight, these antelope are grazers in woodlands, clearings and floodplains. Glandular secretions give them a strong musky odor which lingers where they have been. The females are hornless.
The Nile Lechwe (Kobus megaceros) and the White Eared Kob (Kobus kob leucotis) both usually live in small herds, but at times thousands of the latter may aggregate. Both are grazers and territorial, and the hornless females are colored differently from the males, usually a chestnut shade.
Roan antelope (Hippotragus equinus), related to Sable antelope, have horns in both sexes and reach 600 pounds in weight. They graze in small herds in open or lightly wooded country. The males are territorial but females and calves often form groups of their own.
Environment of the Upper Nile Group
150 miles southwest of Lakeno, Republic of the Sudan
Reeds dominate the banks of small rivers forming the network of the Upper White Nile, which waters an otherwise arid region. Fires such as the one at right in this scene were sometimes deliberately set by local tribesmen to open the ground for easier hunting and to stimulate new growth of grasses.
Audio: Listen to a Hippopotamus
Painted on the near shore, from left, can be seen a snake bird, Anhinga rufa; a group of crowned cranes, Balearica pavonina; shoveler ducks, Spatula clypeata, and pintail ducks, Anas acuta, (at the waters edge); a Marabou stork, Leptoptilos crumeiferus; sacred ibis, Threskiornis aethiopica; Egyptian geese Alophochen aegyptiacus, and two spur-winged geese, Plecthopeterus gambensis (beyond crocodiles). Also appearing, in the sky are a pair of comb ducks Sarkidiornis melanotus (far left), flying behind a flock of three whiteface ducks Dendrogyona viduata; a pair of saddle billed storks Ephippior hynuchus sene galensis (far shore): in the river, white pelicans Pelecanus gnocrotalus; and an African kite Mulucus migrans, flying at extreme right.