Feeding ecology of Southern White Rhinos at Ziwa Rhino Sanctuary in Nakasongola District, Central Uganda

Abstract

Understanding the feeding ecology of animals improves breeding programs and contributes to conservation of biodiversity, but there is limited knowledge about the feeding ecology of Southern White Rhinos at Ziwa Rhino Sanctuary (ZRS). The aim of this study was to investigate the feeding ecology of Southern White Rhinos, and how Rhino grazing influences habits at ZRS. Specifically, the herbaceous species preference by Southern White Rhinos was assessed in Rhino feeding habitats. In addition, the herbaceous plants and tree composition, and species diversity were compared in feeding and non-feeding habits. Within the feeding habitats, two female Southern White Rhinos were followed behind their feeding tracks until they stopped feeding or when they changed to another activity from 20th July to 3rd August 2018. At each feeding site, herbaceous plants grazed were recorded in 10 x 10 m plots. To assess composition and species diversity of herbaceous plants and trees in feeding and non-feeding habitats, all herbaceous plants were recorded in 10 x 10 m plots and woody plants in 30 x 30 m. The results showed that Rhinos prefer feeding on grasses to forbs and that they do not feed on trees. The most preferred grasses were Cyerus rotundus, Lippia nodiflora, Mimosa species and Oxalis latifolia. Rhinos showed a noticeable preference for two forbs, that is, Oxalis latifolia and Lippia nodiflora. The species composition of herbaceous and trees did not differ markedly between feeding and non-feeding habitats. The results also showed that the abundance, richness and diversity of herbaceous plants were higher in feeding than non-feeding habitats. Tree diversity and richness but not abundance were higher in feeding than non-feeding habitats. These results imply that herbaceous plants in feeding habitats showed a positive relationship among abundance richness and diversity.