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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Aspects of the biology, population ecology and behaviour of the sable antelope, Hippotragus niger niger, (Harris, 1838) in the Rhodes Matopos National Park, Rhodesia

Grobler, Johannes Hendrik 10 May 2013 (has links)
The study set out to determine some of the bioecological relationships of the sable antelope Hippotragus niger niger (Harris, 1838) in the Rhodes Matopos National Park, Rhodesia. The vegetation of the area is divided into seven categories each of which is discussed. The population in the study area (approximately 200) had three major components as follows: the breeding groups, the bachelor male groups and territorial males. The structure of the breeding groups varied seasonally. Bachelor male groups of two to 12 consisted of younger males which had as yet not established territories. Territorial males fell into three classes depending on status:- class I: central territorial; class II: peripheral territorial and class III: outer territorial males, in relation to the breeding group home ranges. The population had a recruitment rate of 26 - 29 per cent fron young of the year and a calving percentage of 56 - 67 per cent, calculated towards the end of the year for 1971 and 1972. The male to fenale sex ratio was not significantly different from a l:l ratio for calves and yearlings but in adults the females outnumbered the males significantly. Breeding groups were found to have home ranges ranging in area from 240 ha to 280 ha though this did not apply in the strictest sense. The territories of territorial males were marked by branch breaking on shrubs and were equivalent to home ranges. The territories ranging from 25 ha to 40 ha in size were defended against other territorial males though bachelor males were tolerated. Social organisation of the ropulation wns based on intraspecific aggressiveness and intolerance and the dominance of one individual over another. Various dominance displays are discussed. Although difficult to determine exactly, the gestation period was about 270 days, the peak calving period being early February. The peak rut took place during May and June although fenales were mated at other times during the year. Measurements and mass are given for 47 young calves which were captured, marked and released for field studies. The sable were found to be selective grazers of nediun height grass showing preference for new growth. Sable appeared to be water dependent, drinking mostly from l3h00 to l4h00. Twenty-eight plant species were recorded as food plants, four of which were dicotyledonous. Seasonal use of different habitats was recorded. Mortality factors in the study area included predation, accidental deaths and illegal hunting, with possible mortality from parasite infestation and fighting. Management of the species involves management of the sable population itself and managenent of the habitat in which they live. Management inplications are discussed. AFRIKAANS : Die doel van die huidige studie was om sekere bioekologiese verwantskappe van die Swrartwitpens Hippotragus niger niger (Harris, 1838) te bestudeer in die Rhodes Matopos Nationale Park in Rhodesië. Die plantetgroei van die area is in sewe subklasse verdeel en elk van die subklasse is bespreek. Die bevolking van ongeveer 200 Swartwitpense het uit drie hoof groepe bestaan, nl., die teelgroepe, vrygesel bulgroepe en territoriale bulle. Die samestelling van die teelgroepe het gewissel van seisoen tot seisoen. Die vrygesel bulgroepe het uit twee tot 12 jonger bulle bestaan wat nog nie 'n territoriale gebied afgebaken het nie. Die territoriale bulle kan volgens status in drie groepe verdeel word nl. klas I: sentraal territoriaal; klas II: aangrensend territoriaal en klas III: rand territoriaal ten opsigte van die weidingsgebied van die teelgroepe. Die Swartwitpens bevolking het 'n jaarlikse aanvas van tussen 26 - 29 persent gehad en die kalfpersentasie was tussen 56 - 67 persent. Die syfers is gebaseer op gegewens ingewin gedurende Oktober tot Desember vir die 1971 en 1972 seisoene. Die geslagsverhouding het nie betekenisvol afgewyk van 'n 1:1 verhouding vir kalwers en een tot twee jaar oud diere nie, maar by volwasse diere was daar betekenisvol meer koeie as bulle. / Dissertation (MSc)--University of Pretoria, 1973. / Zoology and Entomology / unrestricted
2

The role of small antelope in ecosystem functioning in the Matobo Hills, Zimbabwe

Lunt, Nicola January 2011 (has links)
The 28-month study assessed the impacts of five syntopic medium-sized mammalian browsers and one fire event in a woodland savanna in the Matobo Hills, Zimbabwe. Aspects of herbivory, mechanical pressures, seed dispersal and nutrient cycling were investigated for three species of small antelope (common duiker [Sylvicapra grimmia]1, klipspringer [Oreotragus oreotragus] and steenbok [Raphicerus campestris]) and two medium-sized species (bushbuck [Tragelaphus scriptus] and greater kudu [T. strepsiceros]). Focusing on Burkea africana2 woodland, in a system that does not include elephant (Loxodonta africana), effects of browsing antelope on woody and herbaceous vegetation development were investigated using exclusion plots. Browsers regulated woody plant cover (measured as basal stem area), with smaller antelope having a greater impact than larger species. This was linked to feeding height, feeding selectivity and mechanical pressures (e.g. twig breakage and trampling). Fire caused an initial reduction in above-ground standing biomass, but in the presence of fauna, pre-fire equilibria were attained within 15 months. In antelope exclosures, herbaceous biomass increased and woody biomass decreased following fire. Responses by woody vegetation to browsing varied among species, with highly palatable species typically exhibiting compensatory regrowth. Woody species richness and abundance (especially of palatable species) increased in the absence of browsers, but species richness of the herbaceous layer was promoted by moderate disturbance (trampling or fire). Faecal deposition behaviour, primarily the use of latrines by small antelope, resulted in localised soil enrichment within defended territories. Decomposition rates (and therefore return of nutrients to the soil) varied among species and seasons, due to defecation site selection, accessibility to decomposers and desiccation rates of faecal pellets. Controlled seed germination experiments indicated that ingestion by small antelope enhances germination rates of large, hard-seeded fruits such as Sclerocarya birrea. However, germination of savanna seeds may require multiple cues. This study demonstrated the critical roles of small antelope in ecosystem functioning, and highlights the importance of the less visible impacts of frequently overlooked smaller mammalian herbivores. Perturbations to the faunal community, especially small antelope, are predicted to have substantial impacts on woody plant cover.

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