Spelling suggestions: "subject:"tsang"" "subject:"tsann""
1 |
Factors limiting the abundance and distribution of hirola (Beatragus hunteri) in KenyaAndanje, Samuel A. January 2002 (has links)
This study investigates the factors limiting the abundance and distribution of hirola, or Hunter's antelope, (Beatragus hunteri), in Kenya's Tsavo East National Park (ex-situ population) and Garissa (in-situ popUlation). The hirola is widely recognized as the most severely threatened monotypic species of antelope in sub-Saharan Africa. Data were collected between 1996 and 2000 on the ex-situ population, with occasional comparative sampling of the in-situ population. The study was carried out almost entirely in the field. Hirola were located by ground searching, by radio tracking and occasionally using aircraft; animals were observed from a landrover. In Tsavo NP the population was found to be static (71.1±9.3 in 844 km2 range), while the Garissa population was declining with about 672 animals remaining in a 5,171 km2 range. Calving in Tsavo took place between August and March, with the peak occurring in late October and early November. About 69.8% of calves died or disappeared within the first 6 months of life and about 18.0% survived to the age of 2 years. Mortality in Tsavo was predominantly associated with predation, while in Garissa, mortality was associated with disease and poaching. Hirola occurred in 8 distinct family groups in Tsavo, each with an adult male and a number of females and their offspring; temporary separations involving the adult male, or females with young, were also recorded. Remarkably, offspring left their natal groups at about 6-15 months of age and spent a period isolated or with other young animals; females eventually rejoined a family group or joined a lone male to form a new group. Young males generally formed bachelor groups and eventually separated as adults to become solitary. Hirola were most active in the early morning hours and late evening when it was cool; hot times of the day were spent resting in the shade of trees and bushes. Densities of other ungulate species within the hirola range varied seasonally, being more abundant in the wet season. Controlling for the relative abundance of other herbivore species, hirola in Tsavo were found to associate predominantly with Grant's gazelle (Ga~ella granfii), while in Garissa they associated mainly with topi (Damaliscus korrigwn). The presence of fewer associates and fewer alternative prey in the dry season appears to have increased the risk of predation to hirola, perhaps due to reduced detection and dilution effects. Home ranges occurred on generally elevated areas associated with red soils (in Tsavo) or sandy soils (in Garissa), and scattered seasonal waterholes. Vegetation in these areas was composed of tall, fairly open bushes interspersed with short green grass patches, that offered preferred food, shade and cover. In Tsavo, hirola fed on a total of 56 plant species (grasses, 74.9%; forbs, 24.2; and sedges, 0.9%) while in Garissa, 27 plant species were eaten (grasses 85.2% and forbs 14.8%). Hirola selected short green grasses and forbs, eating an entire plant (leaf, stem and inflorescence) at a mean bite height of 7.4±3.93SD cm. The nutrient content of the preferred plant species were measured on a seasonal basis. The Garissa population has declined as a result of range reduction, caused by human encroachment. In addition, it has been further affected by poaching and spread of diseases from cattle. The factors limiting the Tsavo population were investigated by multivariate analysis of the relationship between the main candidate factors (estimates of predation pressure, food abundance, shade tree densities, competitors, etc) and variation in the size, reproduction and mortality rates across the hirola family groups studied. The main limiting factors in the Tsavo population appeared to be predation pressure and the amount of specific microhabitats available for shade, cover against predators, and food. Finally, I discuss how these results may shape the development of conservation management strategies for hirola in the future. Recommendations include the restoration of protected areas in Garissa and the establishment of further ex-situ populations, preferably in predator free environments, to allow a rapid increase in numbers and to spread the risk of species extinction.
|
2 |
The role of termites in the ecology of Tsavo National Park, KenyaBuxton, Robin January 1979 (has links)
Tsavo National Park lies in an area of very dry country in South Eastern Kenya. Elephants live there in large numbers and in the early 2 1970's, they had a mean population density of about 1 km<sup>-2</sup> . They have inflicted widespread destruction on the woodlands which originally covered the Park, leading to a complete change in the appearance of the habitat. This caused considerable anxiety about the future of the Park and all its animal populations so research was begun to try to elucidate the root causes of the "elephant problem" and to predict its consequences. The purpose of the present study was to find out what happens to dead wood in Tsavo and to gauge the importance of termites in the ecology of the area. Section 1 gives a brief introduction to the history of Tsavo and sets out the main questions posed when this study was begun. In Section 2 the environment of the study area is described in terms of its topography and geology, the soils and their origins, the floristic and structural composition of the vegetation during this study, the climate and its variations in time and space and the role of fire in shaping the habitat. The species of termites found in the study area are listed in Section 3, followed by brief descriptions of their natural history. Section 4 contains all the information on the turnover of dead wood. The standing crop and rates of wood fall and removal were measured directly at one site and extended by means of an index to measure consumption of dead wood by termites at other sites. Consumption is found to be related to rainfall. The results are discussed in relation to similar studies made elsewhere. A model is constructed relating the consumption of dead wood by termites to rainfall and comparing this with the consumption of grass and browse by large herbivorous mammals. A method is described for measuring the relative importance of different termite species as consumers of dead wood.
|
3 |
The habitats and feeding stations of birds in Tsavo National Park, KenyaLack, Peter C. January 1980 (has links)
The land-bird community of Tsavo East National Park was studied for two years. There are two wet seasons each year: November-December and April- May, but the latter were very poor in both study years. Six habitat types were designated on the basis of canopy cover of woody vegetation. Riverine vegetation was also studied. Most ofthe open habitats extant are derived from woodland by destruction of trees, a process largely caused by elephants. Food supplies are seasonally variable. Insects and grass seeds are most abundant in December and January. In the open habitats the few fruits also peak then, but Commiphora spp., which is only in woodland and is the most abundant fruit in Tsavo, peaks July to September. The ecology of each species of land-bird is described and most are found to be ecologically separate from each other. The annual cycle of numbers of birds in each habitat is closely correlated with the food supplies. In the open habitats birds are almost all insectivorous, granivorous or both, and peak numbers (about five times the dry season density) occur in December and January. In woodland, numbers remain fairly constant through the year and frugivores are more prominent, especially around August. The wet season peaks in all habitats are caused by immigrations of different species, both from elsewhere in Africa most of which come in to breed, and species which breed in the Palaearctic. The August peak in Woodland consists mainly of species which have resident populations. The results are particularly related to the recent habitat changes in the Park. They are compared with other bird studies in African savannas and other components of the Tsavo ecosystem. Finally, the means by which birds are able to survive in the harsh and unpredictable conditions of Tsavo are discussed.
|
4 |
ANALYZING THE DISTRIBUTION OF THE AFRICAN ELEPHANT (LOXODONTA AFRICANA) IN TSAVO, KENYAMukeka, Joseph M. 20 July 2010 (has links)
No description available.
|
5 |
Assessing Spatial and Temporal Patterns of Human-Caused Elephant Mortality in Tsavo East National Park, KenyaKyale, Daniel Muteti 30 November 2006 (has links)
No description available.
|
6 |
Ecological Impact of Epigeal Termitaria on Vertebrates in the Tsavo Region of Southeast KenyaMahan, Margaret M. 01 August 2009 (has links)
Termites ecologically engineer their environment by producing termitaria (mounds) used by many other species as dens, lookouts or food sources. The role of termite mounds in biological communities is relatively unknown, despite their ubiquitous nature. I investigated their impact on vertebrates in the Tsavo region of Kenya. Through the characterization of mounds, trapping, direct observation, and collecting microclimate data, I was able to determine the importance of mounds to vertebrates. I found uniform dispersion of mounds, that soil type is correlated with the size of mounds, and that vertebrate activity increases with mound size. I also found no significant differences in overall numbers of animals and species between mound and non-mound areas. Reptiles were found at mound sites significantly more than at non-mound sites, especially the great plated lizard and short-necked skink. I determined that mounds’ microclimate is less variable than that of the ambient. More work is needed to further our understanding of termite mounds' impacts on vertebrates. This study led to discoveries of species not known to be in the area by myself or my affiliated parties.
|
7 |
An Analysis of Illegal Bushmeat Availability in Local Restaurants Located in Voi, KenyaSutton, Bridget A 01 December 2008 (has links)
The illegal bushmeat harvest has been identified as a reason for declining wildlife populations throughout much of Africa. For many years the trade was thought to exist primarily in Western Africa. The illegal use of bushmeat in Eastern Africa, including Kenya, went undocumented and unstudied. In 2004, the Born Free Foundation published a study which claimed illegal sale of wild game was substantial in butcheries throughout Nairobi, Kenya. In an effort to determine other markets of the commercial trade, the goal of this study was to analyze local restaurants in Voi, Kenya for illegal bushmeat sale. The town of Voi was selected due to recent published reports in the popular press, its proximity to Tsavo National Park, and its access to a major highway. Samples were collected and analyzed using mDNA sequencing analysis of the cytochrome B gene. None of the collected samples were identified as illegal game meat. The restaurants in Voi, Kenya were not a commercial outlet for illegal bushmeat trading in the local economy during the period of this study. The results from this study provide valuable baseline data which can be used in future research to help determine possible vectors of the bushmeat trade.
|
8 |
Landscape Structure of Acacia-Commiphora Bushland in Southeastern KenyaMutiti, Christine Mango 28 July 2010 (has links)
No description available.
|
Page generated in 0.0278 seconds