Habitat use of mountain nyala (Tragelaphus buxtoni, Lyddeker, 1911) in the Bale Mountains National Park, Ethiopia

Abstract

A study on habitat use of the mountain nyala (Tragelaphus buxtoni), an endemic ungulate known to science in 1908, was conducted from May to June 2007 in the Bale Mountains National Park (BMNP). The study area was divided into three major habitat group based upon the dominant vegetation and relative location. Vegetation use by the animal were accessed in randomly laid 171 square plots of 100 m2 area size along randomly established transects. Of 171 plots 69 were in Gaysay grassland, 71 in Adelay and 31 in Dinsho woodland habitat. As related to the species use, of the habitat ground cover, incidence of browsing, vegetation height, slope, altitude, canopy openness, tree density and visibility were measured. Six vegetation types were identified and ranked for their use by T. buxtoni.The largest proportion (58%) of the Gaysay grassland habitat, was covered by grasses. In this habitat,Hypericum revolutum bush was the most used while open grassland was the least. Among the four vegetation groups that were identified in Dinsho woodland habitat, Hagenia and Juniperus and vegetable type covered the largest proportion (68%) in terms of area. In this habitat, open montane grassland vegetation was the most used by the animal; while Euphorbia and Solanum bushy vegetation were the least. Although the least used, in Adelay woodland habitat, Hagenia and Juniperusvegetation types covered the largest proportion (65%) of the area. In most obervation, levels of browsing decreased with increased in vegetation height. Greater availability of a given vegetation type did not necessarily result in higher use by the study animal. Proper conservation measures that could restore or rehabilitate the preferred habitats and vegetation types for the study animal are needed in the Park. Key words: Browse, habitat use, mountain nyala, preference, vegetation.