Feeding Ecology of Warthog, Waterbuck and Tiang During the Dry Season in Dinder National Park, Sudan

Abstract

This study was conducted in Dinder National Park (D.N.P.) during the dry season 2004 (March, April and May). Waterbuck (Kobus defassa), warthog (Phacochoerus aethiopicus) and tiang (Damaliscus korrigum) are among the large herbivores in D.N.P were chosen for this study. Mayas (meadows) habitat are used by these herbivores during the dry season when forage quality and quantity are generally low. Samaaya and Gererrisa mayas were chosen for the study of tiang. Abdel Ghani, Ein El Shames and Samaaya mayas were chosen for studying warthog. Abdel Ghani, Ein El Shames and Musa mayas were chosen for studying waterbuck. The objectives of this study are to determine the botanical composition of the diets of the three herbivores by Microhistological Analysis of fecal samples and to examine the role of the three animals in relation to the distribution of the preferred forage plants in the different habitats. Through the test of germination of undigested seeds being separated from fecal samples of the herbivores. The plant and fecal samples were collected from the above mentioned mayas. Herbarium specimen had been collected and the unknown plant species were identified in Wildlife Research Center and the Herbarium of the Forestry Research Center. Because tiang is an endangered species, few pellets were found and collected from Samaaya maya. Only 18 animals were seen during this study. Analysis of fecal samples indicated that the three herbivores grazed on wide range of species (Mixed diet) from preferred habitats. V Tiang foraged on 35 (mostly forbs) forage plants. The forbs showed highest percentage (44.02%) in total diet of tiang. The major plant species selected by tiang from Samaaya maya were Achyranthes sp, Hibiscus sp, Dichrostachys glomerata and Beckeropsis sp. Warthog ate 46 plants. The woody plants are the major components of the diet of warthog. Ein El Shames maya provide 51.95% of its food and Abdel Ghani maya provide 39.55%.In Samaaya maya, the major components in the diet of warthog are grasses (40.29%). The major forage plants selected by warthog from three mayas were Achyranthes sp, Dichrostachys glomerata, Ziziphus spina-christi and Echinochloa sp. Waterbuck ate 67 plant species. The total diet of waterbuck showed the highest percentage of grasses (50.90%) from Musa maya. While the diet from Abdel Ghani maya, the forbs made the highest percentage (51.61%). The woody plants showed the highest percentage (42.46%) from Ein El shames maya. Achyranthes sp, Achyranthes aspera, Tribulus terrestris, Dichrostachys glomerata, Rottboelia exaltalt and Echinochloa sp were the major forage plant consumed by waterbuck. Spearman's rank order correlation coefficient was used to test the variation in diet composition between the four mayas and the three herbivores. Pearson's correlation coefficient was used to test the herbivores selectivity of the available forage plant in the mayas or the surroundings. All herbivores showed a significant rank order correlation but not in all months. Warthog versus tiang showed significant correlation in May at the level (P < 0.01) from Samaaya maya. Although warthog versus waterbuck showed significant correlation between mayas. Ein El Shames maya showed significant rank order correlation during May, while Abdel Ghani VI maya showed significant correlation during April, both at the level (P < 0.05). The diet of the three herbivores in the four mayas showed high significant correlation at the level (P < 0.05) and level (P < 0.01). Forage plants that were recovered from the fecal samples of tiang and warthog, in Samaaya maya showed no significant correlation with the forage plants estimated by quadrates. Although warthog in Abdel Ghani and Ein El Shames mayas and waterbuck in Abdel Ghani, Ein El Shames and Musa mayas were significantly correlated (P < 0.05). The processes of the digestive systems of the herbivores have positive effect on seed germination. This may result from complex herbivores-specific interactions between animal behaviors (chewing) and seeds characteristics (size, seeds coat, shape). Seeds of Acacia nubica, Acacia seyal and Piliostigma reticulatum that were separated from the fecal samples of waterbuck showed a highly increased rate of germination above the control. Acacia polycantha and Sesbania sesban showed decreased rate of germination below the control. The germination rate of Acacia siberiana showed no positive effect (zero) versus the control. The germination rate of the seeds of Ziziphus-spina-christi remained more or less above control 53% and 50% respectively. The germination of seeds of Ziziphus spina-christi from fecal samples of warthog showed a higher increased rate of germination. The results of this study confirmed that the three wild herbivores are grazers, but they shift their diets towards forbs, woody plants and fruits of leguminous trees during the dry season. They depend on the mayas for their diets, but they select other plant species from the surrounding. Therefore the waterbuck, tiang and warthog have great role in the dispersal of seeds of forage plants VII in their habitats. This study provides the information regarding the food habits and the feed requirements of these wild herbivores. Such information might help in the management of the habitat (Mayas) and the wild herbivores in D.N.P.