Browsing by Author "Admasu Simeneh"

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    Population Status, Distribution and Habitat Association of the Beisa oryx (Oryx beisa beisa) and Its Interactions with Sympatric Species in Alledeghi Wildlife Reserve, Ethiopia
    (Addis Ababa University, 2016-07) Admasu Simeneh; Bekele Afework (Professor)
    Individual count of Beisa oryx (Oryx beisa beisa) was conducted in Alledeghi Wildlife Reserve during September - December, 2015 which covered both wet and dry seasons. Transect count method was used to determine the current population size, group size, demographic composition, seasonal distribution and habitat association of Beisa oryx as well as population status of the two co-occurring wild ungulates (Soemmering’s gazelle and Gerenuk). Twelve parallel sampling transects were systematically placed perpendicular to the baseline with a minimum distance of 2 km apart .The total transect length was 167 km, and given that width of 0.6 km on both sides of each transect, about 200 km2 area (47.6% of the census zone) was sampled during the study. The density of animals observed per transect was used to calculate mean population density. Mean differences in population structure of the species was compared using Tukey’s multiple mean tests. Habitat association and seasonal variation of Beisa oryx and the other two co-occurring ungulates were compared using Chi square test. The population estimate of Beisa oryx was 722. There was a decrease in individuals by 22% compared to the 2009 and 2010 estimates. There was a considerable difference in the number of animals observed during the wet and dry seasons (χ2 = 1252.934 df = 1 P <0.001). A total of 101 herds of Beisa oryx were observed (67 and 34 herds during wet and dry seasons, respectively). The difference was statistically significant (F1, 99 = 79.17, P <0.001). Age structure was mainly dominated by adults (85%), followed by sub-adults (13%). The sex ratio was dominated by females (55.6%). Mean population density of Beisa oryx and the two co-occurring ungulates observed in different habitat types excluding seasons showed non-significant difference. Key words: Alledighe Wildlife Reserve, Beisa oryx, Density, Herd size, Habitat, Season