Palm-Studded Grasslands and Glistening Wetlands of the Selous

Palm-Studded Grasslands and Glistening Wetlands of the Selous

Selous Game Reserve in southern Tanzania is one of Africa's largest protected areas, covering some 50 000 square km (19 300 square m). This makes it more than twice the size of South Africa's Kruger National Park and four times as big as the Serengeti National Park. Only the northern part of Selous is open to tourism, however, as the southern reaches are divided into controlled hunting zones. Perhaps best appreciated from the air, the northern Selous is a spectacular tapestry of wooded savanna, palm-studded grasslands, forested riverbanks and glistening wetlands.

The Selous Game Reserve occupies a largely flat plain between the Udzungwa Mountains and the Indian Ocean. There are some hills in the southwest which rise to 1200 metres (3900 feet), but the land in the north-eastern sector (about 80km/50m from the coast) is just 100 metres (328 feet) above sea level.

Rufiji River

The perennial Rufiji River bisects the Selous Game Reserve and creates a variety of aquatic habitats for wildlife. Several lakes and watercourses, the extent and shape of which are altered depending upon the river flow, are strung out north of the Rufiji. The open water of the river and lakes is home to rich and diverse fish fauna including various catfish, tilapia and tigerfish. These fish form the base of a food chain which includes virtually every species of piscivorous bird known from the African mainland, as well as the continent's densest population of Nile Crocodiles. Great numbers of herbivorous Hippos spend their days in the warm waters, leaving after dark to graze in surrounding grasslands. Waterlilies and other floating plants occur in sheltered bays, providing a micro-habitat for certain birds, frogs and dragonflies.

The Rufiji is shallow in many places and sandy beaches are exposed and submerged depending upon water levels. Birds such as the African Skimmer and White-crowned Lapwing nest on these miniature islands, which are also favoured sunning spots for crocodiles. Steeper sand banks provide breeding habitat for kingfishers, bee-eaters and martins.

Fringing the river and waterways, is dense bushwillow-vernonia scrub or ribbons of riverine forest. These habitats suit a variety of invertebrates, birds and other wildlife. Statuesque Borassus Palms and branching Doum Palms form groves or stand as lonely sentinels close to the water's edge. Birds such as Dickinson's Kestrel, Red-necked Falcon, Egyptian Goose, African Palm-Swift, Open-billed Stork and African Fish-Eagle occupy holes or build their stick nests in these palms. Large Leadwoods, many now leafless skeletons, stand close to the lake shores, while occasional specimens of the magnificent Tall Star-Chestnut with their distinctive yellow trunks stand out like proverbial 'sore thumbs'.

Life in and around the Rufiji is strongly influenced by the volume of water which is dependent not only on rainfall in the catchment areas, but also by the amount of extraction for agriculture and other human activities. Less than 100km (62 miles) from Selous' eastern boundary, the Rufiji River fans out into a vast delta before spilling into the Indian Ocean.

Open Woodland 

Much of the area north of the Rufiji River is open woodland in which the distinctive Flat-crowned Terminalia is conspicuous. A 'hardpan' layer of clay exists at, or just below, the soil surface in this region. The Flat-crowned Terminalia is well adapted to these poorly-drained, shallow soils, along with Tamboti, Brack Thorn, Coastal Whistling-Thorn, Desert Date and Long-tail Cassia. There is virtually no shrub layer in the more open wooded grassland, but the grass cover is attractive to grazing herbivores such as Zebra and Wildebeest. Other mammals which are commonly encountered here include Giraffe, African Elephant, Impala and Greater Kudu which browse the Terminalia and Acacia. Lion, Wild Dog and Spotted Hyena are common large carnivores, while Striped Bush Squirrel and Yellow Baboon are conspicuous. Birds are abundant in wooded grassland, with raptors, rollers, hornbills, woodpeckers, barbets, bushshrikes, warblers, sunbirds and weavers among the best-represented groups.

Grassland

Edaphic grasslands occur on poorly drained clay soils ('cotton soils') in places which are subject to prolonged flooding during the rainy season. During the dry season, this clay soil dries up completely and cracks of up to half-a-metre appear. This process of flooding and cracking renders these areas unsuitable for deep-rooted woody plants so open grassland prevails. Buffalo herds frequent the taller grasslands once they begin to dry out, while Zebra, Wildebeest and Lichtenstein's Hartebeest may graze here during the dry season. Birds such as Secretarybird, Black-chested Snake-Eagle, Rufous-naped Lark, Harlequin Quail and Common Buttonquail are characteristic. In some areas, 'palm stand grassland' dominated by Borassus or Doum palm exists as a distinct habitat.

Tall Woodland

Tall woodland occurs on deep pale-coloured sand, with trees such as Panga-Panga, Pod Mahogany, Mwanga, Monkey-Orange and Two-winged Stink-Bushwillow forming a closed canopy 'coastal sand forest'. These woodlands are a particularly good habitat for certain birds, including many of Selous' most sought-after species. Small groups of Böhm's Bee-eater hawk airborne insects at the forest fringe, while Retz's Helmetshrike and Green Woodhoopoe forage at lower levels. African Golden Oriole, White-breasted Cuckooshrike, Yellow White-eye and Brown-breasted Barbet (illustrated) keep mostly to the woodland canopy. Troops of Angola Pied Colobus may be seen feeding on the leaves of leguminous Milletia and Albizia trees, while the striking Red-bellied Coast-Squirrel forages along larger branches.Selous Safari Camp

CC Africa's Selous Safari Camp is set close to the shore of Lake Nzelekela which is connected to the Rufiji River by a network of channels. Spacious safari tents are nestled within deciduous woodland, while the raised dining and bar areas provide wonderful views across the sparkling wetlands. Activities at Selous Safari Camp include game drives in open vehicles, guided bush walks and boating on the mighty Rufiji River, as well as exciting Walking & Fly Camping safaris.

- Duncan Butchart -

Posted: Other by CC Africa, Date: 21 November 2006