Nutritional Ecology of Waterbuck: Seasonal Variation in Forage Composition and Quality in Dinder National Park

This study was conducted in Dinder National Park (DNP), Sudan, during 2010 and 2011, to determine the botanical composition and nutrient content of the diet of waterbuck (Kobus ellipsiprymnus defassa). Research was focused mainly around Abd el Ghani Maya (meadow). A micro-histological technique was employed to identify dietary plant species by comparing epidermal characteristics of plant samples and faecal droppings. Plant and faecal samples were collected, dried, ground, and analyzed. Additionally, nitrogen, phosphorus, and calcium concentrations in plant samples were measured. Twenty-one plant species were identified in waterbuck feces in 2010, and 19 in 2011. Grasses such as Echinochloa sp., Cyperus sp., Kyllinga sp., and Sorghum arundinaceum were dominant in the diet, alongside forbs including Corchorus depressus, Ipomoea aquatica, and Polygonum sp. Woody species consumed included Acacia seiberiana, Balanites aegyptiaca, Ziziphus spina-christi, and Crateva adansonii. During the early dry season, grasses and forbs comprised 80% of the diet, while trees and shrubs accounted for 20%. This pattern reversed in the late dry season, with grasses and forbs making up 40%, and woody vegetation 60%. Among the food plants, Cyperus sp. and Acacia species exhibited the highest nitrogen and phosphorus contents. The study concludes that waterbuck preference shifts seasonally: selecting a few succulent, nutrient-rich grasses in the early dry season, and diversifying to include more herbaceous and woody plants with relatively high nutrient content during the late dry season when grasses become scarce. These findings provide valuable insight into the feeding ecology and nutritional adaptation of waterbuck in a semi-arid environment.