https://ir.unisa.ac.za/handle/10500/30871 2026-10-05T23:43:11Z 2026-10-05T23:43:11Z Ngombane, Mvelisi https://ir.unisa.ac.za/handle/10500/33039 2026-09-04T08:00:27Z 2026-08-25T00:00:00Z

Prevalence of mites and associated risk factors in village chickens (Gallus gallus domesticus) of Libode in Nyandeni Local Municipality, Eastern Cape Province, South Africa Ngombane, Mvelisi Background: Farming poultry chicken sustains the livelihoods in rural areas where chickens are used as source of proteins and to generate extra income. However, there is an increase of chicken-related health problems in rural poultry which are mostly caused by ectoparasite. Hence, there is a critical need to conduct comparative studies in rural villages to manage the spread of ectoparasite in backyard poultry systems. The study was conducted at six villages located in the Nyandeni Local Municipality (Nyandeni LM), which is part of the OR Tambo District Municipality. These villages are Coza, Ethumbeni, Luthubeni, Mjobeni, Mhlanganisweni-B and Phezukwamawa. Methodology: A cross-sectional epidemiological questionnaire was done to assess the farmers’ chicken farming system, knowledge of ectoparasite infestation and their remedies to treat mites and lice. Screening for mites and lice involved a thorough examination of the chicken’s visible affected areas. Samples were identified following standard parasitological methods and examined under stereo microscope. Results: About 197 chickens (70 males and 127 females) were examined from six Nyandeni villages in the Eastern Cape Province. The overall prevalence of mites recorded was 14.7% (95% Cl =39-46) among 197 poultry farmers examined. More than 15.7% of chickens were infested with lice while 14.7% infestation was due to mites. Of the insecticide used to control the mites and lice, 21% was Madubula followed by Bulala Zonke (15.5%), Blue Death (11%), and Karbadust (8%), and about 90% of farmers agreed that these remedies are reliable with no side effect. The lowest prevalence of mite infestation was in Mjobeni with the prevalence of 7.1% (95% CI = 0-23). The highest prevalence of mite infestation was in Coza with 25.0% (95% CI = 6-47). The difference in overall prevalence between male and female chickens was statistically significant (p ˂ 0.05). In addition, the prevalence of mites and lice infestation was higher in female chickens (mites,18%; lice,18.7%) while male had lower mites (14.4%) and lice (10%) infestations. About 49 chicken farmers participated in the survey with male contributing to 73% and 27% were female. At the time of survey, 14% chicken farmers that were employed and 86% unemployed farmers were fully depending on farming chicken for sustenance and extra cash. Chicken farmers had clear knowledge of mites and lice and the use of alternative method to control the spread of ectoparasite. Conclusion: The prevalence of these mites and lice in the rural villages is the confirmation of poor parasite control and management practices. This suggests the need to develop relevant VII control strategies and train chicken farmers on how to prevent ectoparasite infestations in rural village chickens.

2026-08-25T00:00:00Z Le Roux, Barbara Anne-Marie https://ir.unisa.ac.za/handle/10500/33038 2026-09-04T06:51:52Z 2026-03-01T00:00:00Z

Medium and large mammal site use and environmental correlates in riparian habitats of the Western Cape Le Roux, Barbara Anne-Marie Riparian zones are vital for biodiversity and ecosystem health. This study investigated the site use and detection of riparian mammals at two sites in the Breede–Gouritz Water Management Area using camera traps. Multispecies occupancy models were used to evaluate how variation in habitat characteristics such as vegetation and water quality influenced species site use across two sites and seasons. Site use responses varied across species, sites and seasons: both vegetation structure and water-quality covariates were consistently associated with higher site use of species in summer, while in winter the association was weaker. Water quality covariates overall showed more variable, often weaker effects across both seasons. The findings suggest that riparian mammals are possibly more strongly influenced by vegetation structure than by water quality at both study areas. Future research should focus on additional drivers of site use, such as prey availability and diet composition, especially for semi-aquatic species such as African clawless otter (Aonyx capensis) and water mongoose (Atilax paludinosis)

2026-03-01T00:00:00Z Van der Lith, Dahne https://ir.unisa.ac.za/handle/10500/32503 2026-06-15T11:02:25Z 2025-11-01T00:00:00Z

Determining the long-term effectiveness of an invasive alien plant removal strategy along the Bakwena toll route in Gauteng and North West, South Africa Van der Lith, Dahne Alien invasive plants (AIPs) are major drivers of biodiversity loss, and roads often act as effective corridors for their spread. This study analysed long-term changes in AIPs along the Bakwena N4 Toll Route, South Africa, using annual audit data collected between 2011 and 2024. Biodiversity indices and statistical analyses were used to assess rates of change, identify persistent invasion hotspots, and predict future trends. The study further compared invasion dynamics between the open, grass-dominated Marikana Thornveld and the denser woody Savanna vegetation types along the route, examined patterns across urban, peri-urban, and rural land-use zones, and evaluated the influence of vegetation quality and soil type on AIP presence. Results showed clear contrasts between land-use zones and vegetation structures. Urban areas displayed fluctuating but broadly stable AIP counts, with no significant long-term decline, suggesting continued reinvasion linked to disturbance. Peri-urban areas remained persistent hotspots, supporting high diversity and richness despite management interventions. Rural areas showed significant reductions in AIP densities, although diversity trends were more variable, indicating ongoing species turnover. Plots within the more open Marikana Thornveld differed from those in the other, generally more wooded or structurally complex vegetation types, indicating that vegetation structure may influence invasion patterns along the route. Degraded vegetation quality was strongly associated with invasion hotspots, while soil type showed limited explanatory power. Similarity and dissimilarity indices revealed high turnover in urban assemblages, relative stability in peri-urban environments, and gradual compositional shifts in rural areas. The findings indicate that management has reduced AIP densities in rural sections of the route, but has been less effective in urban and peri-urban areas. Persistent reinvasion in disturbed areas highlights the need for targeted, adaptive management. Sustained monitoring, restoration, and context-specific interventions will be important for maintaining ecological integrity along the Bakwena N4 Toll Route. Acknowledgements in English and Afrikaans

2025-11-01T00:00:00Z Alakram, Suvana https://ir.unisa.ac.za/handle/10500/32369 2026-04-16T11:54:43Z 2026-01-26T00:00:00Z

Beach and dune erosion along the coast of Richards Bay, South Africa and implications for the management of shoreline change Alakram, Suvana Sandy beaches are dynamic in nature and are subject to natural and anthropogenic processes that influence its evolution. One of the key drivers of coastal evolution is the erosion of the coastline. Sandy beaches are more susceptible to erosion because its fine sand is easily erodible. Since approximately 80% of South Africa’s coastline consists of sandy beaches, including environmentally sensitive dune systems, the impetus is to improve our knowledge and understanding of processes taking place at the coastal zone to aid in coastal zone management and planning for future hazards. This research integrated the use of geographical information systems (GIS), remote sensing, and modelling techniques to contribute knowledge on the interrelationships between the spatial and temporal dynamics of shoreline changes along the coast of Richards Bay, South Africa. Shoreline change rates were quantified over a 45 year period between 1977 and 2022 using the United States Geological Survey’s Digital Shoreline Analysis System. The historical data was then used to estimate future shoreline positions 10 and 20 years into the future. The results of the shoreline analysis revealed consistent erosion north of the Richards Bay harbour with a net shoreline movement of 167.80 m in some areas. The beaches south of the harbour recorded an accretional trend with a net shoreline movement of 98.90 m in some areas. The study verified that the development of the port breakwaters has caused an interruption the longshore sediment transport pattern, resulting in accretion on the updrift side (South), and erosion on the downdrift (North). The shoreline change rate statistics were used to predict future shoreline positions using the Extrapolated Linear Regression method 10 and 20 years into the future. In the context of climate change and associated sea level rise, model based approaches in ArcGIS Pro were used to assess the vulnerability of the study area to inundations caused by storm surges. The inundation screening was initated for four different surge levels using a high resolution DEM as input. The results indicated that during a 9 and 10 m storm surge, 60 and 68% of the study area respectively was inundated which serves as important baseline information for disaster risk assessments. This dissertation also explored possible pathways to coastal resilience and proposed strategies to mitigate coastal erosion and flooding in a changing environment.; Strande is dinamies en onderhewig aan natuurlike en antropogeniese prosesse wat die evolusie daarvan beïnvloed. Een van die belangrikste dryfkragte van kusevolusie is erosie van die kuslyn. Strande is meer vatbaar vir erosie omdat fyn sand maklik erodeerbaar is. Ongeveer 80% van Suid-Afrika se kuslyn bestaan uit hoofsaaklik sand dominante strande wat omgewings belangrikke duinstelsels behels. Dus is die doel van hierdie projek om ons kennis en begrip van kussoonprosesse te verbeter asook om te help met kussonebestuur en beplanning vir toekomstige gevare. Hierdie navorsing maak gebruik van ‘n metode wat geografiese inligtingstelsels (GIS), afstandswaarneming en modelleringstegnieke behels. Met die doel om die onderliggende verband tussen die ruimtelike en temporale dinamika van kuslynveranderinge langs die kus van Richardsbaai, Suid-Afrika, beter te verstaan. Die kuslynveranderingstempo's is oor 'n tydperk van 45 jaar, tussen 1977 en 2022, gekwantifiseer met behulp van die Verenigde State se Geologiese Opname se Digitale Kuslynanalisestelsel (DSAS). Hierdie historiese data was gebruik om die toekomstige kuslynposisies te skat oor 10 en 20 jaar. In sommige gebiede het die studie erosie noord van die Richardsbaai-hawe uitgewys met 'n totale kuslynbeweging van 167.80 m. Strande suid van die hawe het 'n akkresionele tendens vertoon met 'n netto kuslynbeweging van 98.90 m in sommige gebiede. Met klimaatverandering en stygende seevlaktes ingedagte, was ArcGIS Pro gebruik om die kwesbaarheid van die studiegebied vir stormvloede te modeleer en assesseer. Vier verskillende stormvloed scenarios was getoets met behulp van hoë resolusie DEMs. Die resultate wys dat 60 of 68 persent van die studiegebied sal vloed met ‘n 9 of 10 m stormvloed scenario en dien as ‘n belangrikke basislyn for toekomstige ramp en risikoassesering. Verder, ondersoek hierdie navorsing opsies om kusveerkragtigheid te verbeter en stel strategië voor om die impak van kuserosie en vloede te versag in ‘n area wat klimaatverandering ondervind. Abstracts in English and Afrikaans

2026-01-26T00:00:00Z