Leopard population density, home range size and movement patterns in a mixed landuse area of the Mangwe District of Zimbabwe
- Authors: Grant, Tanith-Leigh
- Date: 2012
- Subjects: Leopard -- Monitoring -- Zimbabwe , Leopard -- Conservation -- Zimbabwe , Wildlife monitoring -- Zimbabwe , Wildlife conservation -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5726 , http://hdl.handle.net/10962/d1005412 , Leopard -- Monitoring -- Zimbabwe , Leopard -- Conservation -- Zimbabwe , Wildlife monitoring -- Zimbabwe , Wildlife conservation -- Zimbabwe
- Description: Trophy hunting is often employed as a conservation management tool for large predators. However, in order for this method to succeed, hunting levels must be sustainable. Very little robust population data exist for African leopards (Panthera pardus) in general, and almost no density or spatial ecology data exist for leopards in Zimbabwe. Zimbabwe has one of the highest annual CITES leopard trophy hunting quotas in Africa, the sustainability of which has not been assessed, despite large scale landuse changes over the last 12 years. The focal area of this study was within the Mangwe district, in the south-west of Zimbabwe. The region is dominated by cattle and wildlife ranches, with high levels of leopard hunting, making it an important area for assessing leopard population density and spatial ecology. Three population density estimation methods were employed in my study: a spoor index survey, an unbaited camera-trapping survey and a baited camera-trapping survey. Using three calibration equations, spoor indices appeared to underestimate the leopard population (1.28-3.29 leopards/ 100 km²) as the equations were calibrated for areas with different habitats and leopard densities. In addition, the unbaited camera survey only produced six leopard photographs, unsuitable for individual identification and analysis. By contrast, the baited camera survey produced 292 identifiable leopard photographs, from which 13 individuals were identified. Density estimates calculated using the programme CAPTURE and the M[subscript]h model with the Mean Maximum Distance Moved Outside of Study Area (MMDMOSA) buffer method (4.79±0.83 leopards/100 km²), and the programme SPACECAP, using a buffer of 2.5 km (5.12±0.62 leopards/100 km²), appeared to generate the most reliable leopard population estimates. To assess the spatial ecology, three leopards (one male, two females) were captured and fitted with GPS collars. The home range estimates of the three leopards (95% Kernel UD: male 263 km², females 31 and 45 km²) were smaller than those of leopards in more arid regions, but larger than those of mesic habitats. This suggests that the Mangwe area has a higher quality habitat than the arid regions of Namibia, but less suitable habitat than protected bushveld areas (e.g. Kruger National Park, South Africa). My data represents the first robust leopard density and home range assessment for Zimbabwe. In addition, my results indicate that the current hunting quota issued to the Mangwe area is unsustainable. Consequently, I recommend revising the quota to five leopards for the entire area, and halving the current national leopard quota to 250, until a national leopard census is completed.
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- Date Issued: 2012
An investigation into the effect of particulate solids on certain antimicrobial preservatives in pharmaceutical and cosmetic suspensions
- Authors: Horn, Norman Robert
- Date: 1978
- Subjects: Drugs -- Preservation , Drugs -- Microbiology , Cosmetics -- Preservation , Cosmetics -- Microbiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3848 , http://hdl.handle.net/10962/d1012436 , Drugs -- Preservation , Drugs -- Microbiology , Cosmetics -- Preservation , Cosmetics -- Microbiology
- Description: Pharmaceutical and cosmetic preparations must be formulated so as to assure elegance of appearance, efficacy of ingredients and a satisfactory shelf life as the product. If the formulation is not self-preserving and if it contains material which could act as a substrate for growth of micro-organisms, the shelf life aspect involves, in addition to several other factors, the choice of a suitable antimicrobial preservative. Such preservatives, when present in the minimum effective concentration, are unfortunately prone to interact with many other materials. A number of papers on the inactivation of preservatives by containers, filters and formulation components have been published. The field has been adequately reviewed by de Navarre (1962), Wedderburn (1964) and, more recently, by Coates (1973). From these reviews and from a study of the literature it became apparent that relatively little work had been done on interactions between preservatives and solid particles in aqueous suspension. Consequently, a range of preservatives not previously investigated in this respect was tested for loss of activity in the presence of fifteen powders commonly used in aqueous suspension in pharmaceutical and cosmetic formulations. In view of the information obtained in this preliminary study and after the development of more satisfactory analytical techniques it was decided to study in greater depth the interaction between these powders and selected organomercurials and quaternary ammonium compounds.
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- Date Issued: 1978
The parasite complex of the citrus psylla, trioza erytreae (Del Guercio) (Homoptera)
- Authors: McDaniel, J. R.
- Date: 1971
- Subjects: Psylla -- Regulation , Citrus , Biological control systems , Parasites
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5865 , http://hdl.handle.net/10962/d1012866
- Description: 1. Fifteen parasite species comprising the T. erytreae complex in Salisbury are listed. 2. Detailed, illustrated accounts are given of the biology of two primary parasites, Tetrastichus Pradiatus Waterston and Psyllaephagus pulvinatus (Waterston ), and their main hyperparasite, Aphidencyrtus cassatus Annecke. 3. The biology of the remaining twelve less important hyperparasites is briefly described and illustrated. 4. Keys are given to the adults, pupae and pupal remains of the parasites. 5 . The population fluctuations of T. erytreae and its parasites, as determined from field studies in the Salisbury area, are reported . 6. The interrelationships between T. erytreae and its parasites are summarised and discussed. Summary, p. 89.
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- Date Issued: 1971
An investigation of the profiles of bursts of solar radio noise
- Authors: Wild, Peter Anthony Thornton
- Date: 1960
- Subjects: Solar radio emission , Radio noise , Solar noise storms , Radio astronomy
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5551 , http://hdl.handle.net/10962/d1013504
- Description: [Summary] Chapter I . The general characteristics of solar radiation at metre wavelengths are described, with reference to data published in the literature. A brief description of some aspects of solar physics relevant to the study of solar noise is given, and the literature relating to the correlation of radio effects with solar disturbances is reviewed. Chapter II. A concise description of the apparatus constructed for the continuous recording of the flux density of solar radio noise at a frequency of 300 Mc/s is given, with some mention of difficulties experienced, and how these were overcome. Full circuit diagrams of electronic apparatus, and illustrative photographs, are supplied. Chapter III. The development of theories of the origin and propagation of solar noise radiation is historically reviewed and the success of each theory in explaining or predicting observed phenomena, is assessed. A working model is chosen from among these theories, and reasons for its adoption are given. Chapter IV. Observations made by the author of solar radiation at a frequency of 300 Mc/s are described, together with a description of the objects and methods, of analysis of the records. Chapter V. Phenomena observed by the author are compared with those observed by other workers. It is concluded that storm bursts are caused by transients similar to those producing Type II and Type ITI bursts, and a model for the production of storm bursts is tentatively suggested. Chapter VI. Suggestions for further research, including suggestions for methods of testing the author's conclusions, are made.
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- Date Issued: 1960