Botanical composition and some nutrient contents of the diet consumed by waterbuck (Kobus ellipsiprymnusdefassa) in Dinder National Park, Sudan

Abstract

This study was conducted in the Dinder National Park (DNP) at approximately 11 to 13oN and long 34 to 36oE) in 2015 and 2016, in order to determine the botanical composition of the waterbuck’s (Kobus ellipsiprymnusdefassa) diet. The study was mainly done at Abd el Ghani Maya (meadow). A micro-histological technique was used to determine the dietary botanical composition in which samples of plant species and faecal droppings encountered in and around the Maya were collected, dried and grounded to pass 1-mm mesh. Reference slides were prepared from the ground samples of the plant species whose epidermal characteristics were compared with their counterparts in similar slides prepared from the faecal droppings. In addition, nitrogen, phosphorous and calcium concentrations in plant samples were determined. Twenty-one plant species were recorded from waterbuck faecal in 2015 and 19 in the year 2016. The grass species comprising high proportions in the diet were Echinochloa sp., Cyprus sp., kylinga sp. and Sorghum arundinaceum; forbs (broad-leaved herbs) were Corchorus depressus, Ipomoea aquatica and Polygonum sp.; and woody vegetation (trees and shrubs) were Acacia seiberiana, Balanites aegyptiaca, Ziziphus-spina-christiand Crativa adonsonii. Early in the dry season, grasses and forbs constituted 80% of the diet, trees and shrubs 20%. However, during the late dry season, grasses and forbs comprise about 40% of the diet; whereas trees and shrubs constituted 60%. Among food plants Cyprus sp. and Acacias contained the highest nitrogen and phosphorus concentrations. The diet of waterbuck was more diverse in the late dry season than that of the early dry season. It is concluded that waterbuck preferred few succulent, nutritious grasses in the early dry season and shifts to diverse herbaceous and woody vegetation with relatively high nutrient contents when the grasses dry up late in the dry season. Nutritional studies about grasses, leguminous trees and other plant species eaten by the wild animals are lacking. Intensive nutritional studies are needed to cover all possible nutritional aspects of the wild animals in the park.