Diversity, Relative Abundance and Distribution of Medium and Large Sized Mammals of Goji and Nopha, Becho District, South Western Ethiopia

Abstract

This study was conducted to survey and determine the diversity, relative abundance, distribution of medium and large size mammals in Nopha and Goji forests from February 2020 - September 2020. Preliminary survey was conducted and two habitat type:-, dense forest and woodland habitats were identified. A line transect survey method was implemented to record the mammalian diversity. Representative sample blocks were taken from each habitat type. Line transect method was employed for the two habitat types and species identification and counting of individuals were made along each transect. In addition to direct observation, indirect methods such as scat/dropping, spines and calls were also used for identification of mammals. A total of 22 mammal species belonging to 7 orders and 13 families were recorded from the study area during both seasons. Among these, four species: Vervet monkey (Chlorocebus aethiopis), Stark’s hare (Lepus starcki), Bush hyrax ( Heterohyrax brucei) and White tailed mangoose ( Icheumia albicauda) were medium-sized and the remaining 18 species were large-sized mammals. Order Carnivora has the highest number of species with nine species followed by Primates and Artiodactyla with five and four species respectively. Order Tubulindentata, Lagomorpha, Hyracoidea and Rodentia were represented by one species each. Among the 22 species of mammals, Vervet monkey (Chlorocebus aethiops) was the dominant mammalian species followed by Olive baboon (Papio anubis) and Colobus monkey(Colobus guereza) and Lion (pantherleo), leopard (panthera pardus) and white tailed mongoose (Icheumia albicauda) were the least abundant species. Dense forest habitats had the highest mammalian species diversity during the dry season with the diversity index (H’) 2.497and the least diversified habitat was woodland (H‟=1.625) in the same season. The abundant mammal species in the study area were Vervet monkey (C. aethiopis) (22.61%) , Olive baboon (P. anubis) (21.55%) and Colobus monkey (C. guereza) ( 17.31% ) were the most abundant species, whereas leopard (Panthera pardus) and lion (Panthera leo) were fewer than 1% of the total observation. Among the two habitat types the highest Simpson’s index (SI) similarity of mammalian species was obtained from dense forest and woodland both during the dry (0.86) and wet season (0.76) respectively. Despite the study area provided habitats for various species of mammals, human influence such as intensive deforestation for agricultural expansion, charcoal production, fuel wood collection, and grazing by livestock resulted in alteration of the natural forest in the study area. This finding showed that attention should be given to the varieties of mammal species to avoid any aspect of human pressures.