Abstract Mammals function as ecological engineers. The ecological relevance of mammals, shortage of data and increased human threats make the matter very essential and necessary to evaluate their diversity and current conservation status. Mammals’ diversity and their threats in Faragosa Communal Forest (FCF) areas are poorly surveyed. The study aimed at assessing medium and large-sized mammals of the study area, and their major threats in FCF. Survey of mammals conducted from August to December 2019 in FCF, Gamo zone, Southern Ethiopia. Transect line method using direct and indirect field observations used to collect data on mammals and their threats. A total of 685 individuals were id belonging to twenty-one mammalian species, six orders and thirteen families were observed. Hystrix cristata, Xerus rutilus, Marmota monax, Mellivera capensis, Chlorocebus aethiops, Papio anubis, Colobus guereza, Civettictis civetta, and Lapus hassinicus were among the medium-sized mammals while Tragelaphus imberbis, Redunca redunca, Ourebia ourebi, Sylvicapra grimmia, Phacochoerus aethiopicus, Pontamochoreus larvatus, Hippopothamus amphibus, Orycteropus afer, Crocuta crocuta, Panthera leo, Panthera pardus, and Canis mesomelas were the large mammals of the study area. Papio anubis and Chlorocebus aethiops were the dominant species identified. The abundant order recorded by the number of observations was order Primates (284 individuals) followed by order Artiodactyla (201 individuals) while the least abundant order was Tubulidentata (8 individuals). Among observed 685 mammals, 371 (54.16%) individuals were recorded in dry season while 314 (45.84%) individuals were recorded in wet season and abundance significantly varied between seasons (2 = 40.783; df = 20; < 0.05). The prevailing threatening factors identified were logging of trees for fuelwood and house construction, overgrazing, deforestation, hunting, mining, and invasive alien plants. As the area is rich in mammals and threatened by different factors, urgent conservation action is highly recommended. K E Y W O R D S diversity, Ethiopia, Faragosa forest, mammals, threats

Study of the carnivore guild is the key to understand quantitative relationship between members of the carnivore community. The aim of the study was to investigate diversity, abundance and population structure of the mongoose in Nech Sar National Park. Ecological data collection on mongoose species has been carried out from September 2017 to August 2018 in Nech Sar National Park (NSNP). Based on the habitat type and topography of NSNP, 10 transects, each of 4-5 km long were sampled to traverse the major habitat types in the park. Line transect distance sampling methodology was used to determine abundance and population status. DISTANCE (Version 6.0, Release 2) Software was used for density and abundance estimation of mongoose populations. The key to distance sampling analyses is to fit a detection function to the observed distances, and hence, the key functions hazard rate + hermite polynomial, unform + cosine polynomial and half normal + hermite polynomial models were chosen over the others on the basis of best fit. Three species of mongoose namely- Egyptian mongoose (Herpestes ichneumon,) Slender mongoose (Herpestessanguineus) and White tailed mongoose (Ichneumiaalbicauda) were identified in the study. The overall density of mongoose in the study area was 2.3048+0.16070 individuals/km2 with population estimate of 943+85.593 individuals. Based on season and habitat type, density and abundance estimates showed variation (P<0.05). However, species composition between seasons and habitats was the same. The highest species diversity (H=1.197) was recorded in bushland habitat. The population was female-baised with 1:1.171 and 1:1.59, male to female ratio during wet and dry seasons, respectively. Adult to young (subadult and juvenile) ratio was1.05:1 and 0.94: 1 during wet and dry seasons, respectively. Further researches on other ecological parameters viz. behavior, feeding habit and activity pattern are important to acquire a complete picture about mongoose ecology in the park.