Sitatunga (Tragelaphus spekii, p.l. sclater) diet and habitat selection in Rushebeya-Kanyabaha Wetland, South Western Uganda

Abstract

This study was conducted in Rushebeya-Kanyabaha wetland, in south western Uganda, from January to December 2008. The aim was to assess the diet and habitat selection of sitatunga (Tragelaphus spekii), a highly wetland restricted antelope threatened by habitat loss. The study was based on the hypotheses that Tragelapsus spekii diet is not diverse and does not differ between seasons; and that there is no significant difference in sitatunga habitats in Rushebeya-Kanyabaha wetland. Micro histological faecal analysis and vegetative sampling methods were used to assess plant forms, plant species, plant parts eaten by sitatunga and seasonal fluctuations in the sitatunga diet. Habitat use was indirectly determined by assessing sitatunga feeding patterns, distribution of sitatunga dung and sitatunga trails within the wetland. Field data were collected along 60 transects (each about 1000 m long) established at 250m intervals covering the entire wetland. In addition, a total of 30 faecal samples were analyzed in the laboratory. Sitatunga fed mainly on leaves and buds of a variety of herbs, sedges, grasses and shrubs comprising a total of 34 plant species. Sitatunga mainly fed on sedges from the family Cyperaceae (49% and 29% of observations from micro histological analysis and vegetation sampling respectively) and herbaceous plants (36% and 40% by micro histological analysis and vegetation sampling respectively). The most eaten plant species was Cyperus papyrus L. (22%). Malenthera scandens Schum. & Thonn., Polygonum senegalense Meisu (12%) and Polygonum pulchrum Blume (5%) were the most eaten herbs. Zea mays L. was the most eaten agricultural crop (58% of agricultural crops). Crop raiding by sitatunga was mainly in the wet season. Sitatunga feeding was mainly concentrated on the wetland edge habitat (46%) where most of its food (53%) was located. The most preferred habitats included the wetland edge and tall closed papyrus. The long term survival of sitatunga requires developing a management plan for wetlands focussing on the conservation of the most preferred plant species and habitats.