Browsing by Author "Bekele Afework (PhD)"

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    The Assessment of Elephant Population Size and Distribution Patterns in the Mago National Park
    (Addis Ababa University, 1998-09) Demeke Yirmed; Bekele Afework (PhD)
    The subspecies of the African elephant, Loxodonta africana knochenhaueri, was studied in the Mago National Park to determine population numbers, distribution by seasons and migration routes. The current poaching situation, population age structure and the size of the animals home-range were also assessed. The study was carried out between June 1997 and April 1998. The population size of elephant was estimated indirectly from the droppings using line transect method within a 1,564 km2 area. The total estimate of the elephant population for the Mago National Park was between 380 and 442. The observed density for the whole park was 0.18 elephant!km2. Elephant numbers Were also estimated directly from sightings. The maximum number observed in a herd was 182. Information on the age structure (determined from hind footprint lengths) indicates that the majority of the population was largely composed of subadult males, adult females and intermediates. Yearlings and juveniles Were very few. Observations and information from the local people on elephant migration and movement patterns suggest that some of the elephants move south to Murle Controlled Hunting Area travelling about 43 km outside the park areas. The total range traversed from north to south by elephants ofMago is about 129 km. The calculated average home-range is 1,597 km2 • A total of 82 plant species that elephants feed on were collected and identified. The study also indicates that poachers have made intensive exploitation of elephants for different purposes. The availability of modem fire arms to the local people in the South Omo has made poaching a serious problem. For example, a total of37 elephants were killed for ivory between December 1996 and April 1998. Most of the poaching activities took place in the dry season. The presence of beehives in the Mago National Park has also contributed for the serious decline of wild animals and contraction of their range. A total of ten thousand beehives were estimated for the whole park areas.
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    Ecological Study of the Avifauna and Bird Strike Problem At Addis Ababa Bole International Airport
    (Addis Ababa University, 1996-05) Yohannes Elizabeth; Bekele Afework (PhD)
    The avifauna of the Addis Ababa Bole International Airport was studied to describe the ecological relationship of the birds and bird strike problem at the airport. The bird composition and abundance were studied using a transect and modified point count method. Visitor and Transient birds were further categorized depending on their frequency of occurrence. Cluster analysis and Principal Component Analysis were employed to sumrnarizethe relationship of the ,', ---'-- '>' -, ''-,-' ---:,' --"'-';O'!;;"'-.-:i>,_-- birds between each other. Diversity of the birds was estimated using Shannon - Weiver Diversity Index. The Biomass and the Species Richness of the birds were computed. The duration and rate of bird strike incidents were analyzed. A preliminary investigation was made on the Vegetation, Invertebrates, Herpetiles and Small Mammals. A total of 70 bird species were identified. The birds were classified into 12 Orders. Fiftyseven per cent of the birds belong to the Order Passeriformes. Birds of Prey comprised 15% of the bird species at Bole. Eighty - four per cent of the birds from Bole were visitors that stayed at the airport in search offood, water and/or sheher. The others were transient birds that used the airport airspace as their passage route to their feeding or nesting sites. Three of the transient birds pass across the airport frequently in a regular time of the day. Thirty of the visitor bird species appeared in the airport very infrequently while 12 were residents. There is no clear variation in the abundance of each species in time. However, six major groups of birds were produced in the cluster analysis indicating each cluster appeared in the airport at a similar instance. The airport was found to be characterized by birds of high diversity and low density. The vegetation structure and rainfall played important roles in determining the species diversity and richness of the birds. The invertebrates, herpetiles, and small mammals, garbage dmnps and other biological and physical factors attract the birds to the airport. September and October were the worst months for aviation. No bird strike was observed in May and June. Pigeons and Black Kites played the major role in air strike incidents. Seventy per cent of the strikes occurred before noon, which is also the time for heavy air traffic. Maintaining the grass at an optimal height, prohibiting agricuhural activities around the airport, clearing open garbage ". . - --',< ,.' dmnps in and around the airport and the use of insecticide spray to eliminate insects in the vegetation around the runway are suggested. However, the nse of integrated approach is recommended to be even more effective.
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    Electrophoretic Study of Transferrin and Pseudocholinesterase on Vervet Monkeys (Cercopithecus aethiops aethiops L.)
    (Addis Ababa University, 1996-05) Nurhusien Omar; Bekele Endashaw (PhD); Bekele Afework (PhD)
    Blood serum samples (n=34) were taken from a population of vervet monkeys inhabiting the terrain along the Awash River. Genetic variation on transferrin (Tf) and pseudocholinesterase (Psch) were studied using a non-denaturing vertical polyacrylamide gel electrophoresis system. No variation was detected on transferrin. Psch was found to be polymorphic with respect to mobility and activity level. Four phenotypes were distinguished based on this polymorphism. This included: single cathodal band with strong activity; single anodal band with strong activity; two bands of activity (one cathodal and the other anodal) and finally no band activity. These phenotypes could be explained based on a three allele model proposed from a previous study. These alleles are designated as psch' for the silent gene, psch' for the cathodal band and psch' for anodal band activities. The genotypes of each individual were constructed and the gene frequencies calculated. The gene frequency for pSChl, psch' and psch3 were 0.0883 and 0.3088 and 0.6029 respectively. Test for goodness-of-fit for these alleles showed the popUlation to be in a Hardy-Weinberg Equilibrium (X2 3=4.95, p > .05) at present. However, when the results of this study were compared with a previous study (some 20 years ago) on the same area, the allelic frequencies have greatly changed. Possible factors responsible for the Tf monomorphism and Psch polymorphism are discussed. The Tf monomorphism may be due to the low migration rate; the antagonistic effect of the Psch third aile on rare Tf allele and the effect of sampling size. The shift in Psch allelic frequency polymorphism may be accounted for by environmental factors. The effect of the 1974 and 1985 drought periods is may have contributed to the dominance of the third allele. The Hitch-Hiking effect on the rapid shift of allele frequency and the effect of methods employed are also discussed. Based on the allelic distribution, important sites for the conservation of vervet monkeys are recommended.
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    Population Status and Diet of Starck’s Hare (Lepus starcki Petter, 1963) in Bale Mountains National Park, Ethiopia.
    (Addis Ababa University, 2007-04) Mekonnen, Tariku; Bekele Afework (PhD)
    The population status and diet of Starck’s hare Lepus starcki Petter, 1963 was investigated in the Bale Mountains National Park from June-September (wet season) and December-January (dry season) in 2006/2007. A survey of population status was undertaken using distance sampling method. The density of Starck’s hare was estimated to be 18.35 per km2 during the wet season (with 95% confidence interval 12.47-26.99). The estimated density during the dry season was 13.33 per km2 (95% CI 9.17-19.39). The population in the study area was estimated to be 6300 during the wet season (95% CI 4300-9200) and 4600 during the dry season (95% CI 3100-6600). More hares were detected from Sanetti Plateau and the least was from Web Valley (Kotera). Line intercept method was used to estimate the coverage of vegetation in the study area. Vegetation coverage was high (65.21%) during the wet season and low (<30%) during the dry season. 27 plant species were identified (21 herbs, 4 grasses and 2 shrubs). Diet was identified by direct observation and analyzing faecal pellets and stomach contents. Monocotyledons (grasses) occurred in higher percentage frequency in the diet of Starck’s hare during both seasons. Among the grasses, Festuca spp. was the most available and important food resources during both seasons.