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Accueil du site → Doctorat → États-Unis → 1981 → Ecological separation of wild and domestic mammals in an East African ecosystem

Utah State University (1981)

Ecological separation of wild and domestic mammals in an East African ecosystem

Bunderson, William Trent

Titre : Ecological separation of wild and domestic mammals in an East African ecosystem

Auteur : Bunderson, William Trent

Université de soutenance : Utah State University

Grade : Doctor of Philosophy (PhD) 1981

Research herein described involved a broad ecological study of an economically undeveloped region encompassing the lamu and southern garissa districts of Kenya. This area is under pressure for a landuse development strategy which will contribute to the rising demands of Kenya’s rapidly expanding human population. However, development plans have been hindered by conflicts among agriculture, livestock ranching, traditional land-uses, and wildlife conservation. These problems have been compounded by a lack of ecological data on which to base sound land-use policies. This study was designed to provide fundamental information on the ecology of the Lamu-Garissa area for aid in making land-use plans which would integrate the conservation and utilization of wildlife with overall strategies for the region’s economic development. Specific aims were : (1) to define and map habitat types of the area ; (2) to determine the numbers, seasonal distributions, and habitat utilization patterns of major wild and domestic mammals ; and (3) to make recommendations for conservation of wildlife. The thesis of the study was to elucidate the mechanisms by which diverse communities of wild mammals are able to co-exist, and to evaluate the effects of pastoral man and his domestic livestock on these communities. The approach used emphasized differences in habitat preferences among species, rather than differences in diets and feeding activities. A total of 19 habitat types were delineated, but only 17 were sufficiently large for examining animal-habitat relationships. The results showed that the distributions and habitat selectivity of wild and domestic herbivores were more restricted in the dry season, when food and water were less abundant. During the wet season animals used a wider array of habitats because of improved forage conditions and better water distribution. Wildlife species appeared to co-exist through differential patterns of habitat use. The observed ecological separation was most evident in the dry season, suggesting that wild animals have evolved specialized habitat and feeding characteristics for reducing interspecific competition during periods of resource scarcity. Strong evidence indicated that current livestock densities have no adverse effects on wildlife. In fact, there is reason to believe that grazing by livestock may alter the structure of vegetation in favor of certain species of wildlife. It is stressed that these conditions occur under a system where overgrazing is not apparent, and livestock are grazed in a nomadic fashion, which enables wildlife to graze areas not occupied by livestock. One implication of this research is that the tsetse fly zone, which contains few livestock relative to the tsetse-free zone, is underutilized by wildlife. Cattle could be introduced for commercial production without adverse consequences to wildlife. However, unlike the nomadic practices of Somali and Orma pastoralists, intensive ranching is inherently sedentary in nature and would disrupt wildlife movements. The result would likely be a decline in wildlife numbers. A similar situation would occur if pastoralists become more sedentary and if their animal numbers are increased to a point where overgrazing occurs. Recommendations were therefore made to set aside regions for wildlife conservation. Such areas could be developed for tourism in a system which would enhance the economic stability of the Lamu-Garissa region while preserving its natural resources.

Sujets : Somali (African people) ; Orma (African people) ; Pastoralists ; Ecology ; Livestock ; Lamu, Kenya ; Garissa, Kenya ; Land use ; Wildlife ; Habitats ;


Page publiée le 12 janvier 2017