Decolonisation of nature in towns and cities of South Africa:
- Cocks, Michelle L, Shackleton, Charlie M, Walsh, Lindsey S, Haynes, Duncan, Manyani, Amanda, Radebe, Dennis
- Authors: Cocks, Michelle L , Shackleton, Charlie M , Walsh, Lindsey S , Haynes, Duncan , Manyani, Amanda , Radebe, Dennis
- Date: 2020
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/175720 , vital:42618 , ISBN 9781000215182
- Description: Ways of conceptualising the world around us and being in this world are defined by an ontological understanding. Within a Eurocentric ideological understanding, nature is positioned to be opposite to culture, ie, nature is considered as “other” of which humans are not a part. Modernity is perceived as the antithesis of nature as processes of production, metabolism and expansion of modern cities represent attempts to tame and control nature. In turn, cities have become viewed as agents of development and change, promoting ideals of progress, thinking and innovation (Jayne 2005). Eurocentric ideals are framed as the forerunners of these processes and have come to influence international policies, global governance, alliances and networks which have in turn informed the design and governance of cities and influenced all aspects of urban liveability (Bouteligier 2011), including how urban natures are defined and constructed and the wellbeing benefits derived from them.
- Full Text:
- Date Issued: 2020
- Authors: Cocks, Michelle L , Shackleton, Charlie M , Walsh, Lindsey S , Haynes, Duncan , Manyani, Amanda , Radebe, Dennis
- Date: 2020
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/175720 , vital:42618 , ISBN 9781000215182
- Description: Ways of conceptualising the world around us and being in this world are defined by an ontological understanding. Within a Eurocentric ideological understanding, nature is positioned to be opposite to culture, ie, nature is considered as “other” of which humans are not a part. Modernity is perceived as the antithesis of nature as processes of production, metabolism and expansion of modern cities represent attempts to tame and control nature. In turn, cities have become viewed as agents of development and change, promoting ideals of progress, thinking and innovation (Jayne 2005). Eurocentric ideals are framed as the forerunners of these processes and have come to influence international policies, global governance, alliances and networks which have in turn informed the design and governance of cities and influenced all aspects of urban liveability (Bouteligier 2011), including how urban natures are defined and constructed and the wellbeing benefits derived from them.
- Full Text:
- Date Issued: 2020
Anthropogenic threats to resident and dispersing African wild dogs west and south of the Kruger National Park, South Africa
- Watermeyer, Jessica Patricia
- Authors: Watermeyer, Jessica Patricia
- Date: 2012
- Subjects: African wild dog -- South Africa -- Kruger National Park , African wild dog -- Effect of human beings on -- South Africa -- Kruger National Park , African wild dog -- Behavior -- South Africa -- Kruger National Park , Endangered species -- South Africa -- Kruger National Park , African wild dog -- Dispersal -- South Africa -- Kruger National Park , African wild dog -- Conservation -- South Africa -- Kruger National Park , Animal populations -- Estimates -- South Africa -- Kruger National Park
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5636 , http://hdl.handle.net/10962/d1005318 , African wild dog -- South Africa -- Kruger National Park , African wild dog -- Effect of human beings on -- South Africa -- Kruger National Park , African wild dog -- Behavior -- South Africa -- Kruger National Park , Endangered species -- South Africa -- Kruger National Park , African wild dog -- Dispersal -- South Africa -- Kruger National Park , African wild dog -- Conservation -- South Africa -- Kruger National Park , Animal populations -- Estimates -- South Africa -- Kruger National Park
- Description: African wild dog Lycaon pictus populations are declining and the species is listed as Endangered by the IUCN. The Kruger National Park (KNP) is home to the only viable population of wild dogs in South Africa, but census results reveal consistently low numbers since the late 1990s. Wild dogs display wide-ranging behaviour and it is possible that the species might frequently use unprotected lands adjacent to the KNP. However, very little is known about wild dog movements beyond the boundaries of the KNP, and whether or not adjacent land owners are tolerant of the species. Significantly, threats along the boundaries may have negative consequences for the KNP population. This research investigated the dispersal habits of wild dogs beyond the western and southern boundaries of the KNP, and gathered information on human tolerance, and anthropogenic threats in an area of mixed land use. The land west of the KNP presented the best prospect for wild dog range expansion. The wild dog packs operating outside the KNP had smaller home ranges and less home range overlap than the packs operating within the KNP. In addition, my data suggested that the development of conservancies and the formation of ecotourism-based land use practices would be beneficial for wild dog conservation. Failed wild dog dispersals due to snaring and human persecution could threaten the genetic stability and persistence of the KNP population. Therefore, raising awareness and an understanding of the plight of wild dogs is important for improving land owner perception and tolerance outside of protected areas. The rapidly increasing human population continues to infringe on protected lands and fragment landscapes, thus cooperation from individual land owners is vital for the conservation of free-ranging large carnivores.
- Full Text:
- Date Issued: 2012
- Authors: Watermeyer, Jessica Patricia
- Date: 2012
- Subjects: African wild dog -- South Africa -- Kruger National Park , African wild dog -- Effect of human beings on -- South Africa -- Kruger National Park , African wild dog -- Behavior -- South Africa -- Kruger National Park , Endangered species -- South Africa -- Kruger National Park , African wild dog -- Dispersal -- South Africa -- Kruger National Park , African wild dog -- Conservation -- South Africa -- Kruger National Park , Animal populations -- Estimates -- South Africa -- Kruger National Park
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5636 , http://hdl.handle.net/10962/d1005318 , African wild dog -- South Africa -- Kruger National Park , African wild dog -- Effect of human beings on -- South Africa -- Kruger National Park , African wild dog -- Behavior -- South Africa -- Kruger National Park , Endangered species -- South Africa -- Kruger National Park , African wild dog -- Dispersal -- South Africa -- Kruger National Park , African wild dog -- Conservation -- South Africa -- Kruger National Park , Animal populations -- Estimates -- South Africa -- Kruger National Park
- Description: African wild dog Lycaon pictus populations are declining and the species is listed as Endangered by the IUCN. The Kruger National Park (KNP) is home to the only viable population of wild dogs in South Africa, but census results reveal consistently low numbers since the late 1990s. Wild dogs display wide-ranging behaviour and it is possible that the species might frequently use unprotected lands adjacent to the KNP. However, very little is known about wild dog movements beyond the boundaries of the KNP, and whether or not adjacent land owners are tolerant of the species. Significantly, threats along the boundaries may have negative consequences for the KNP population. This research investigated the dispersal habits of wild dogs beyond the western and southern boundaries of the KNP, and gathered information on human tolerance, and anthropogenic threats in an area of mixed land use. The land west of the KNP presented the best prospect for wild dog range expansion. The wild dog packs operating outside the KNP had smaller home ranges and less home range overlap than the packs operating within the KNP. In addition, my data suggested that the development of conservancies and the formation of ecotourism-based land use practices would be beneficial for wild dog conservation. Failed wild dog dispersals due to snaring and human persecution could threaten the genetic stability and persistence of the KNP population. Therefore, raising awareness and an understanding of the plight of wild dogs is important for improving land owner perception and tolerance outside of protected areas. The rapidly increasing human population continues to infringe on protected lands and fragment landscapes, thus cooperation from individual land owners is vital for the conservation of free-ranging large carnivores.
- Full Text:
- Date Issued: 2012
The potential influence of commercial plant nurseries in shaping the urban forest in South Africa
- Arnoldi, Marco, Shackleton, Charlie M
- Authors: Arnoldi, Marco , Shackleton, Charlie M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/398408 , vital:69409 , xlink:href="https://doi.org/10.1016/j.ufug.2021.127254"
- Description: A substantial portion of urban green infrastructure is under private tenure in residents’ and business/corporate gardens. Therefore, the ways that urban residents manage their gardens can influence the type, quantity and quality of ecosystem services and disservices in urban areas. Plant nurseries are a major source of trees for urban residents, and so the types of trees and species that nurseries stock influence the composition of private gardens. Consequently, this study aimed to examine the roles that plant nurseries play in shaping the urban forest in South Africa. To do so, an online and direct questionnaire was used to gather data from 30 nurseries across 19 urban centres in South Africa. The main questions included species selection criteria, customer tree inquiries, best-selling tree species, attitudes towards increasing urban tree cover and diversity and whether they think climate change will affect the selection of species to stock. The results show that there is a strong preference for indigenous trees, which were also most commonly listed as best-sellers. Non-native species that were commonly sold were ones that provided provisioning services, particularly edible fruits. Drought tolerance influenced selection criteria and customer demand. Vachellia spp. and Olea europaea were commonly inquired about and most commonly listed amongst the best-sellers. Nursery owners valued the importance of increasing tree cover and diversity in urban areas, listing many perceived benefits for doing so. We conclude that there is a clear preference for indigenous tree species by customers and nursery owners, which in time could increase the proportion and cover of native species.
- Full Text:
- Date Issued: 2021
- Authors: Arnoldi, Marco , Shackleton, Charlie M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/398408 , vital:69409 , xlink:href="https://doi.org/10.1016/j.ufug.2021.127254"
- Description: A substantial portion of urban green infrastructure is under private tenure in residents’ and business/corporate gardens. Therefore, the ways that urban residents manage their gardens can influence the type, quantity and quality of ecosystem services and disservices in urban areas. Plant nurseries are a major source of trees for urban residents, and so the types of trees and species that nurseries stock influence the composition of private gardens. Consequently, this study aimed to examine the roles that plant nurseries play in shaping the urban forest in South Africa. To do so, an online and direct questionnaire was used to gather data from 30 nurseries across 19 urban centres in South Africa. The main questions included species selection criteria, customer tree inquiries, best-selling tree species, attitudes towards increasing urban tree cover and diversity and whether they think climate change will affect the selection of species to stock. The results show that there is a strong preference for indigenous trees, which were also most commonly listed as best-sellers. Non-native species that were commonly sold were ones that provided provisioning services, particularly edible fruits. Drought tolerance influenced selection criteria and customer demand. Vachellia spp. and Olea europaea were commonly inquired about and most commonly listed amongst the best-sellers. Nursery owners valued the importance of increasing tree cover and diversity in urban areas, listing many perceived benefits for doing so. We conclude that there is a clear preference for indigenous tree species by customers and nursery owners, which in time could increase the proportion and cover of native species.
- Full Text:
- Date Issued: 2021
The feasibility of reintroducing African wild dogs (Lycaon pictus) into the Great Fish River Nature Reserve, Eastern Cape, South Africa
- Authors: Page, Samantha Karin
- Date: 2014
- Subjects: Great Fish River Nature Reserve (South Africa) , African wild dog -- South Africa -- Eastern Cape , Population biology -- South Africa -- Eastern Cape , African wild dog -- Reintroduction -- South Africa -- Eastern Cape , African wild dog -- Population viability analysis -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5915 , http://hdl.handle.net/10962/d1016078
- Description: With a declining population of roughly 3000-5000 individuals in Africa, African wild dogs (Lycaon pictus) are one of the most endangered carnivores in the world. As the global human population expands, it is becoming increasingly unlikely that large portions of land will be set aside for conservation, especially in developing countries. Thus, recent wild dog conservation efforts in South Africa have concentrated on establishing a managed metapopulation. A metapopulation is a group of geographically isolated subpopulations of a species that are managed (using supplementation and harvesting) to mimic natural gene flow. The Great Fish River Nature Reserve (GFRNR) in the Eastern Cape Province of South Africa has been identified as a potential reserve to become part of the national wild dog metapopulation. My research aimed to conduct a feasibility assessment of the long-term (~ 25 years) success of a wild dog reintroduction into the GFRNR. This assessment included biological modelling of wild dogs and their expected prey, and determining the potential anthropogenic threats to wild dogs on the private and communal land surrounding the reserve. I used VORTEX population modelling and determined that the GFRNR is likely to have a wild dog carrying capacity of ~22 individuals. Using a 25-year modelling simulation, the most appropriate wild dog reintroduction scenario would be to reintroduce six females and four males initially and supplement the population with one female and two males in years 3, 10, 15 and 23. In addition, the harvesting/removal of one male and one female in years 10 and 20 would be required to ensure 100% population persistence and adequate genetic diversity. Kudu (Tragelaphus strepsiceros) and bushbuck (Tragelaphus scriptus) are expected to be the two most important prey species for reintroduced wild dogs in the GFRNR. Furthermore, wild dogs are likely to prefer the north-western and south-western sectors of the reserve because of the relatively high prey densities in these areas. However, regular monitoring of both the potential prey and the wild dog populations is essential to ensure persistence of the wild dogs and to prevent prey populations decreasing precipitously. Using structured questionnaire interviews (n = 128), I found that while neighbouring land owners and local communities were generally positive about the potential wild dog reintroduction (56 % of all respondents), several threats to wild dogs were identified along the reserve boundary and on the adjoining unprotected land. Some private landowners and members of rural communities around the reserve (34 %) stated that they would kill any wild dogs that dispersed onto their land. In addition, some respondents (8 %) admitted to believing in traditional uses for wild dog products (e.g. fur) which could result in the illegal killing of wild dogs outside of the GFRNR for traditional purposes. Poaching and the presence of unvaccinated domestic dogs on neighbouring land were also identified as being potential threats to a reintroduced wild dog population. However, such anthropogenic threats appear to be localised to the western and southern boundaries of the reserve. Therefore, by implementing preventative measures (such as anti-snare collars, anti-poaching patrols and vaccination against rabies and canine distemper) the likelihood of such threats occurring can be reduced. I conclude that the GFRNR can sustain a population of wild dogs and successfully contribute to South Africa‘s national metapopulation. An additional reserve will benefit the country‘s metapopulation by increasing the number of wild dogs available for translocation, thereby increasing genetic diversity and overall resilience (to environmental change, disease etc.) of South Africa‘s wild dog population. This will contribute towards the future conservation of this endangered species.
- Full Text:
- Date Issued: 2014
- Authors: Page, Samantha Karin
- Date: 2014
- Subjects: Great Fish River Nature Reserve (South Africa) , African wild dog -- South Africa -- Eastern Cape , Population biology -- South Africa -- Eastern Cape , African wild dog -- Reintroduction -- South Africa -- Eastern Cape , African wild dog -- Population viability analysis -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5915 , http://hdl.handle.net/10962/d1016078
- Description: With a declining population of roughly 3000-5000 individuals in Africa, African wild dogs (Lycaon pictus) are one of the most endangered carnivores in the world. As the global human population expands, it is becoming increasingly unlikely that large portions of land will be set aside for conservation, especially in developing countries. Thus, recent wild dog conservation efforts in South Africa have concentrated on establishing a managed metapopulation. A metapopulation is a group of geographically isolated subpopulations of a species that are managed (using supplementation and harvesting) to mimic natural gene flow. The Great Fish River Nature Reserve (GFRNR) in the Eastern Cape Province of South Africa has been identified as a potential reserve to become part of the national wild dog metapopulation. My research aimed to conduct a feasibility assessment of the long-term (~ 25 years) success of a wild dog reintroduction into the GFRNR. This assessment included biological modelling of wild dogs and their expected prey, and determining the potential anthropogenic threats to wild dogs on the private and communal land surrounding the reserve. I used VORTEX population modelling and determined that the GFRNR is likely to have a wild dog carrying capacity of ~22 individuals. Using a 25-year modelling simulation, the most appropriate wild dog reintroduction scenario would be to reintroduce six females and four males initially and supplement the population with one female and two males in years 3, 10, 15 and 23. In addition, the harvesting/removal of one male and one female in years 10 and 20 would be required to ensure 100% population persistence and adequate genetic diversity. Kudu (Tragelaphus strepsiceros) and bushbuck (Tragelaphus scriptus) are expected to be the two most important prey species for reintroduced wild dogs in the GFRNR. Furthermore, wild dogs are likely to prefer the north-western and south-western sectors of the reserve because of the relatively high prey densities in these areas. However, regular monitoring of both the potential prey and the wild dog populations is essential to ensure persistence of the wild dogs and to prevent prey populations decreasing precipitously. Using structured questionnaire interviews (n = 128), I found that while neighbouring land owners and local communities were generally positive about the potential wild dog reintroduction (56 % of all respondents), several threats to wild dogs were identified along the reserve boundary and on the adjoining unprotected land. Some private landowners and members of rural communities around the reserve (34 %) stated that they would kill any wild dogs that dispersed onto their land. In addition, some respondents (8 %) admitted to believing in traditional uses for wild dog products (e.g. fur) which could result in the illegal killing of wild dogs outside of the GFRNR for traditional purposes. Poaching and the presence of unvaccinated domestic dogs on neighbouring land were also identified as being potential threats to a reintroduced wild dog population. However, such anthropogenic threats appear to be localised to the western and southern boundaries of the reserve. Therefore, by implementing preventative measures (such as anti-snare collars, anti-poaching patrols and vaccination against rabies and canine distemper) the likelihood of such threats occurring can be reduced. I conclude that the GFRNR can sustain a population of wild dogs and successfully contribute to South Africa‘s national metapopulation. An additional reserve will benefit the country‘s metapopulation by increasing the number of wild dogs available for translocation, thereby increasing genetic diversity and overall resilience (to environmental change, disease etc.) of South Africa‘s wild dog population. This will contribute towards the future conservation of this endangered species.
- Full Text:
- Date Issued: 2014
Impacts of a trophy hunting ban on private land conservation in South African biodiversity hotspots:
- Parker, Kim, de Vos, Alta, Clements, Hayley S, Biggs, Duan, Biggs, Reinette
- Authors: Parker, Kim , de Vos, Alta , Clements, Hayley S , Biggs, Duan , Biggs, Reinette
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158219 , vital:40163 , https://0-doi.org.wam.seals.ac.za/10.1111/csp2.214
- Description: Private land conservation areas (PLCAs) have become critical for achieving global conservation goals, but we lack understanding of how and when these areas respond to global pressures and opportunities. In southern Africa, where many PLCAs rely on trophy hunting as an income‐generating strategy, a potential ban on trophy hunting locally or abroad holds unknown consequences for the future conservation of these lands. In this study, we investigate the consequences of a potential trophy hunting ban in PLCAs in two biodiversity hotspots in South Africa's Eastern and Western Cape provinces. We used semistructured interviews with PLCA managers and owners to elicit perceived impacts of an internationally imposed trophy hunting ban on conservation activities in PLCAs, and to probe alternative viable land uses.
- Full Text:
- Date Issued: 2020
Impacts of a trophy hunting ban on private land conservation in South African biodiversity hotspots:
- Authors: Parker, Kim , de Vos, Alta , Clements, Hayley S , Biggs, Duan , Biggs, Reinette
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158219 , vital:40163 , https://0-doi.org.wam.seals.ac.za/10.1111/csp2.214
- Description: Private land conservation areas (PLCAs) have become critical for achieving global conservation goals, but we lack understanding of how and when these areas respond to global pressures and opportunities. In southern Africa, where many PLCAs rely on trophy hunting as an income‐generating strategy, a potential ban on trophy hunting locally or abroad holds unknown consequences for the future conservation of these lands. In this study, we investigate the consequences of a potential trophy hunting ban in PLCAs in two biodiversity hotspots in South Africa's Eastern and Western Cape provinces. We used semistructured interviews with PLCA managers and owners to elicit perceived impacts of an internationally imposed trophy hunting ban on conservation activities in PLCAs, and to probe alternative viable land uses.
- Full Text:
- Date Issued: 2020
Could a regulated market approach for rhinoceros horns work in South Africa? Some practical issues and concerns
- Collins, Alan, Fraser, Gavin C G, Snowball, Jeanette D
- Authors: Collins, Alan , Fraser, Gavin C G , Snowball, Jeanette D
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68600 , vital:29292 , http://www.essa2013.org.za/fullpaper/essa2013_2708.pdf
- Description: Publisher version , One of the proposals for fighting rhinoceros poaching is to legalise the trade in rhino horn and adopt a regulated market approach (RMA), which would require a vote at the 2016 CITES meeting in order to overturn the ban on the trade in rhino horn. The legal trade in rhino horn would enable the auctioning of stockpiles of horn and encourage captive breeding programmes. The aim of increasing the supply of horn is to reduce incentives to poach by driving down the price. This paper uses a conceptual/theoretical approach to consider the practical implications of the adoption of an RMA, drawing on demand, supply and production theory. The intention is explicitly to set out some practical concerns and issues that seem to have been underplayed or neglected in most published economic discourse on the subject. To secure a stockpile for some species needs biological success in captive breeding programs (CBPs) but this varies across species and habitats. Rhinoceros herds in a CBP would need relatively spatially extensive terrain and costly permanent security measures, and only appear feasible for the less aggressive “white” rhino. Thus, market price would actually need to be sustained at a high level to cover the start-up and security costs of such a programme that are unlikely to fall significantly. This is a double-edged sword in that the persistent high price of rhino horn provides an incentive for continued poaching activities. Supplementary policy measures that differentiate among consumer groups may also prove necessary.
- Full Text:
- Date Issued: 2013
- Authors: Collins, Alan , Fraser, Gavin C G , Snowball, Jeanette D
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68600 , vital:29292 , http://www.essa2013.org.za/fullpaper/essa2013_2708.pdf
- Description: Publisher version , One of the proposals for fighting rhinoceros poaching is to legalise the trade in rhino horn and adopt a regulated market approach (RMA), which would require a vote at the 2016 CITES meeting in order to overturn the ban on the trade in rhino horn. The legal trade in rhino horn would enable the auctioning of stockpiles of horn and encourage captive breeding programmes. The aim of increasing the supply of horn is to reduce incentives to poach by driving down the price. This paper uses a conceptual/theoretical approach to consider the practical implications of the adoption of an RMA, drawing on demand, supply and production theory. The intention is explicitly to set out some practical concerns and issues that seem to have been underplayed or neglected in most published economic discourse on the subject. To secure a stockpile for some species needs biological success in captive breeding programs (CBPs) but this varies across species and habitats. Rhinoceros herds in a CBP would need relatively spatially extensive terrain and costly permanent security measures, and only appear feasible for the less aggressive “white” rhino. Thus, market price would actually need to be sustained at a high level to cover the start-up and security costs of such a programme that are unlikely to fall significantly. This is a double-edged sword in that the persistent high price of rhino horn provides an incentive for continued poaching activities. Supplementary policy measures that differentiate among consumer groups may also prove necessary.
- Full Text:
- Date Issued: 2013
The dispersal of African wild dogs (Lycaon Pictus) from protected areas in the Northern KwaZulu‐Natal Province, South Africa.
- Whittington‐Jones, Brendan Mark
- Authors: Whittington‐Jones, Brendan Mark
- Date: 2012
- Subjects: African wild dog , African wild dog -- Conservation -- South Africa -- KwazuluNatal , African wild dog -- Dispersal -- South Africa -- KwaZulu-Natal , African wild dog -- Effect of human beings on -- South Africa -- KwaZulu Natal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5893 , http://hdl.handle.net/10962/d1013414
- Description: The number of African wild dogs Lycaon pictus in Northern KwaZulu‐Natal, South Africa has increased substantially over the last six years. This is largely due to a managed metapopulation approach of introductions onto protected areas and private game reserves since 1998. Because of the increasing wild dog population, the likelihood of rural communities surrounding protected areas encountering dispersing wild dogs in northern KwaZulu‐Natal has also increased. Resident wild dog populations currently occur in Hluhluwe‐iMfolozi Park (HiP), Mkhuze Game Reserve (MGR) of Isimangaliso Wetland Park and Thanda Private Game Reserve (TPGR) all of which are bordered by a matrix of natural habitats and human settlements. Thus, land outside these protected areas could be utilized to expand wild dog distribution and provide connectivity between existing resident populations of wild dogs within KwaZulu‐Natal. To investigate the viability of such an approach, Maximum Entropy Modelling (Maxent) was used to characterize habitat niche selection of dispersing wild dogs, and to identify potential dispersal linkages between current wild dog metapopulation reserves. The model was calibrated using 132 location points collected from 2006 until 2009. From 2008 to 2009 I also conducted a survey of 247 community members in tribal authorities bordering HiP and MGR, to understand factors influencing attitudes towards wild dogs. A habitat suitability model with seven predictor variables had an AUC of 0.96 (SD = 0.02) and indicated four variables which best predicted probability of presence for dispersing wild dogs: elevation, road density, land cover and human density. The results suggest that elevation and land cover may be of greater influence for dispersing wild dogs than human density or activity. Elevation was the single most effective variable indicating a higher probability of presence for dispersing wild dogs in lower lying locations; peaking at approximately 200 – 300m a.s.l. Wild dogs also showed a preference for Woodland and Bushland habitats which in KwaZulu‐Natal tend to be found on lower lying topography. A preference for areas of lower human density and a highest probability of presence at road densities of approximately 0.7km/km2 or less would suggest that while wild dogs may show a tendency to avoid areas of high human activity, they can coexist in close proximity to humans. Respondent’s attitudes, knowledge of wild dogs and livestock husbandry were interpreted by the development of a set of indices. Attitudes were positively related to formal education levels and wild dog‐specific education, but were not influenced by demographic factors such as gender, age and employment status. Eighty three percent of respondents believed efforts to protect wild dogs should continue. Respondents with higher numbers of livestock tended to have more positive attitudes towards wild dogs despite generally incurring higher losses to carnivore depredation than those with less livestock. This appears to be because the financial burden of livestock losses to those with fewer livestock is perceived to be a loss of a greater proportion of total financial wealth. The study highlighted the substantial scope for improvement in livestock management. Theft (34 percent), drought (30 percent) and disease (14 percent) were ranked as the greatest problems facing livestock owners while predators were ranked as the greatest problem by only 4 percent of respondents. My findings suggest that wild dogs are generally viewed positively or with ambivalence. Concerns over the potentially increasing threat to livestock, as natural prey numbers outside protected areas decline and wild dogs disperse from natal packs, are likely to be manageable. However, wild dog population expansion within KwaZulu‐Natal will continue to rely on managed core populations on perimeter‐fenced metapopulation reserves with tolerant communities and landowners contributing to the connectivity of isolated reserves. Generation of tolerance can be instilled through continued advocacy and education, supported by conflict mitigation initiatives and rapid response to conflict reports. The implementation of incentive schemes for adjoining private landowners to co‐manage wild dog populations will need to be addressed in conjunction with managed metapopulation practices and law enforcement, to promote range expansion, and reduce potentially lethal edge effects and wild dog‐human conflict.
- Full Text:
- Date Issued: 2012
- Authors: Whittington‐Jones, Brendan Mark
- Date: 2012
- Subjects: African wild dog , African wild dog -- Conservation -- South Africa -- KwazuluNatal , African wild dog -- Dispersal -- South Africa -- KwaZulu-Natal , African wild dog -- Effect of human beings on -- South Africa -- KwaZulu Natal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5893 , http://hdl.handle.net/10962/d1013414
- Description: The number of African wild dogs Lycaon pictus in Northern KwaZulu‐Natal, South Africa has increased substantially over the last six years. This is largely due to a managed metapopulation approach of introductions onto protected areas and private game reserves since 1998. Because of the increasing wild dog population, the likelihood of rural communities surrounding protected areas encountering dispersing wild dogs in northern KwaZulu‐Natal has also increased. Resident wild dog populations currently occur in Hluhluwe‐iMfolozi Park (HiP), Mkhuze Game Reserve (MGR) of Isimangaliso Wetland Park and Thanda Private Game Reserve (TPGR) all of which are bordered by a matrix of natural habitats and human settlements. Thus, land outside these protected areas could be utilized to expand wild dog distribution and provide connectivity between existing resident populations of wild dogs within KwaZulu‐Natal. To investigate the viability of such an approach, Maximum Entropy Modelling (Maxent) was used to characterize habitat niche selection of dispersing wild dogs, and to identify potential dispersal linkages between current wild dog metapopulation reserves. The model was calibrated using 132 location points collected from 2006 until 2009. From 2008 to 2009 I also conducted a survey of 247 community members in tribal authorities bordering HiP and MGR, to understand factors influencing attitudes towards wild dogs. A habitat suitability model with seven predictor variables had an AUC of 0.96 (SD = 0.02) and indicated four variables which best predicted probability of presence for dispersing wild dogs: elevation, road density, land cover and human density. The results suggest that elevation and land cover may be of greater influence for dispersing wild dogs than human density or activity. Elevation was the single most effective variable indicating a higher probability of presence for dispersing wild dogs in lower lying locations; peaking at approximately 200 – 300m a.s.l. Wild dogs also showed a preference for Woodland and Bushland habitats which in KwaZulu‐Natal tend to be found on lower lying topography. A preference for areas of lower human density and a highest probability of presence at road densities of approximately 0.7km/km2 or less would suggest that while wild dogs may show a tendency to avoid areas of high human activity, they can coexist in close proximity to humans. Respondent’s attitudes, knowledge of wild dogs and livestock husbandry were interpreted by the development of a set of indices. Attitudes were positively related to formal education levels and wild dog‐specific education, but were not influenced by demographic factors such as gender, age and employment status. Eighty three percent of respondents believed efforts to protect wild dogs should continue. Respondents with higher numbers of livestock tended to have more positive attitudes towards wild dogs despite generally incurring higher losses to carnivore depredation than those with less livestock. This appears to be because the financial burden of livestock losses to those with fewer livestock is perceived to be a loss of a greater proportion of total financial wealth. The study highlighted the substantial scope for improvement in livestock management. Theft (34 percent), drought (30 percent) and disease (14 percent) were ranked as the greatest problems facing livestock owners while predators were ranked as the greatest problem by only 4 percent of respondents. My findings suggest that wild dogs are generally viewed positively or with ambivalence. Concerns over the potentially increasing threat to livestock, as natural prey numbers outside protected areas decline and wild dogs disperse from natal packs, are likely to be manageable. However, wild dog population expansion within KwaZulu‐Natal will continue to rely on managed core populations on perimeter‐fenced metapopulation reserves with tolerant communities and landowners contributing to the connectivity of isolated reserves. Generation of tolerance can be instilled through continued advocacy and education, supported by conflict mitigation initiatives and rapid response to conflict reports. The implementation of incentive schemes for adjoining private landowners to co‐manage wild dog populations will need to be addressed in conjunction with managed metapopulation practices and law enforcement, to promote range expansion, and reduce potentially lethal edge effects and wild dog‐human conflict.
- Full Text:
- Date Issued: 2012
Issues and concerns in developing regulated markets for endangered species products: the case of rhinoceros horns
- Collins, Alan, Fraser, Gavin C G, Snowball, Jeanette D
- Authors: Collins, Alan , Fraser, Gavin C G , Snowball, Jeanette D
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124877 , vital:35706 , https://doi.org/10.1093/cje/bev076
- Description: A proposal for addressing rhinoceros poaching is to legalise the trade in rhino horn and adopt a regulated market approach, overturning the current trade ban. This orthodox economic prescription aims to reduce incentives to poach endangered wildlife by driving down the market price of their products via auctioned stockpile releases. Biologists are clear, however, that securing a stockpile for some species needs biological success in captive breeding programmes (CBPs), which varies markedly across species and habitats. Rhinoceros herds in a CBP would need spatially extensive terrain and costly permanent security measures; this only appears feasible for the less aggressive ‘white’ rhino. We argue that the market price would actually need to be sustained at a high level to cover protection costs over the longer reproduction cycles in CBPs and that, without extensive monitoring and the correct institutional structures being in place, legalising trade may encourage, rather than prevent, poaching. Supplementary policy measures that differentiate among consumer groups would also likely prove necessary.
- Full Text:
- Date Issued: 2015
- Authors: Collins, Alan , Fraser, Gavin C G , Snowball, Jeanette D
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124877 , vital:35706 , https://doi.org/10.1093/cje/bev076
- Description: A proposal for addressing rhinoceros poaching is to legalise the trade in rhino horn and adopt a regulated market approach, overturning the current trade ban. This orthodox economic prescription aims to reduce incentives to poach endangered wildlife by driving down the market price of their products via auctioned stockpile releases. Biologists are clear, however, that securing a stockpile for some species needs biological success in captive breeding programmes (CBPs), which varies markedly across species and habitats. Rhinoceros herds in a CBP would need spatially extensive terrain and costly permanent security measures; this only appears feasible for the less aggressive ‘white’ rhino. We argue that the market price would actually need to be sustained at a high level to cover protection costs over the longer reproduction cycles in CBPs and that, without extensive monitoring and the correct institutional structures being in place, legalising trade may encourage, rather than prevent, poaching. Supplementary policy measures that differentiate among consumer groups would also likely prove necessary.
- Full Text:
- Date Issued: 2015
The potential for voluntary instruments to achieve conservation planning goals : the case of conservancies in South Africa
- Downsborough, Linda, Shackleton, Charlie M, Knight, Andrew T
- Authors: Downsborough, Linda , Shackleton, Charlie M , Knight, Andrew T
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6629 , http://hdl.handle.net/10962/d1006821
- Description: Spatial prioritizations and gap analyses are increasingly undertaken to allocate conservation resources. Most spatial prioritizations are conducted without specifying the conservation instruments to be implemented and gap analyses typically assess formally protected areas but increasingly include private land conservation instruments. We examine conservancies to see if these voluntary instruments contribute towards achieving goals of South African conservation planning initiatives. We conducted a nationwide survey and interviews with conservancy members in Gauteng and the Eastern Cape. Conservancies have potential for assisting South Africa to achieve conservation planning goals at national and local scales but their inclusion in spatial prioritizations and gap analyses predicates improved protection for nature, operational refinement and increased support. We sound a warning to conservation planning initiatives that incorporate voluntary instruments on private land, and present recommendations for strengthening such instruments to make them more effective. Our findings may assist conservation planners elsewhere to design more effective conservation planning initiatives focused on private land.
- Full Text:
- Date Issued: 2011
- Authors: Downsborough, Linda , Shackleton, Charlie M , Knight, Andrew T
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6629 , http://hdl.handle.net/10962/d1006821
- Description: Spatial prioritizations and gap analyses are increasingly undertaken to allocate conservation resources. Most spatial prioritizations are conducted without specifying the conservation instruments to be implemented and gap analyses typically assess formally protected areas but increasingly include private land conservation instruments. We examine conservancies to see if these voluntary instruments contribute towards achieving goals of South African conservation planning initiatives. We conducted a nationwide survey and interviews with conservancy members in Gauteng and the Eastern Cape. Conservancies have potential for assisting South Africa to achieve conservation planning goals at national and local scales but their inclusion in spatial prioritizations and gap analyses predicates improved protection for nature, operational refinement and increased support. We sound a warning to conservation planning initiatives that incorporate voluntary instruments on private land, and present recommendations for strengthening such instruments to make them more effective. Our findings may assist conservation planners elsewhere to design more effective conservation planning initiatives focused on private land.
- Full Text:
- Date Issued: 2011
The synthesis and characterisation of Sn(IV) porphyrin derivatives and their potential application in anti-cancer and antimicrobial photodynamic therapy
- Authors: Dingiswayo, Somila
- Date: 2021-10
- Subjects: Porphyrins , Photochemotherapy , Cancer Photochemotherapy , Active oxygen Physiological effect , Aromaticity (Chemistry) , Tetrapyrroles , Magnetic circular dichroism , Corroles , Chlorins , Photodynamic antimicrobial chemotherapy (PACT)
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/10962/188843 , vital:44791
- Description: In photodynamic therapy (PDT), the activation of light-sensitive drugs in tumour cells produces reactive singlet oxygen species, which cause tumour destruction through a cascade of biochemical reactions. Over the years, the wavelength of activation has been shown to be a critical factor in the penetration of light. Hence the properties of photosensitiser dyes in this context shape their ability to treat deep-seated tumours. In this study, the synthesis, structural characterisation and photophysicochemical properties of a series of Sn(IV) porphyrins with meso-methylthiophenyl rings that have been prepared to study their PDT and photodynamic antimicrobial chemotherapy (PACT) activity properties are reported. The series of Sn(IV) complexes is comprised of a porphyrin (1-Sn), a corrole (2-Sn), a chlorin (3-Sn) and an N-confused porphyrin (4-Sn). Herein, the low symmetry Sn(IV) porphyrin derivatives are shown to have excellent singlet oxygen generation capabilities, and lifetimes of the triplet excited states were in the microsecond range. For example, 4-Sn had a singlet oxygen quantum yield (ФΔ) and an excited triplet state lifetime (τT) of 0.88 and 27 μs, respectively. The complexes were studied using UV-visible and magnetic circular dichroism (MCD) spectroscopies. Interestingly, the positive-to-negative sign sequences of the Faraday B0 terms of 2-Sn and 3-Sn reveal that the structural modifications involved break the degeneracy of the MOs derived from the 1eg* LUMO of the porphyrin 1-Sn. In contrast, a conventional negative-to-positive sign sequence is observed for 4-Sn, since the confusion of a pyrrole moiety also results in a large separation of the 1a1u and 1a2u MOs of the porphyrin 1-Sn that are derived from the HOMO of a C16H162−parent hydrocarbon perimeter. The trends in the electronic structures of the Sn(IV) complexes were further investigated through a series of time-dependent density functional theory calculations, so that the suitability of the different types of complex for use in singlet oxygen applications could be further explored. During in vitro photodynamic antimicrobial chemotherapy (PACT) studies, chlorin derivative 3-Sn had the highest activity towards S. aureus and E. coli with log10 reductions of 10.5 and 8.74, respectively. The unusually high activity of 3-Sn against E.coli suggests that the interaction of neutral photosensitisers with gram-negativebacteria is more complex than previously understood. Anti-cancer PDT studies demonstrated that the photosensitisers had negligible dark cytotoxicity. Upon photoirradiation, the Sn(IV) complexes consistently exhibited IC50 values lower than 15 μM against MCF-7 adenocarcinoma cells. An IC50 value of 1.4 μM for 4-Sn after activation at the deep-red region of the spectrum demonstrates that complexes of this type merit further in-depth investigation. The results provide evidence that the low-symmetry Sn(IV) chlorins and N-confused porphyrins merit further in-depth study for use in singlet oxygen applications. , Thesis (MSc) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Dingiswayo, Somila
- Date: 2021-10
- Subjects: Porphyrins , Photochemotherapy , Cancer Photochemotherapy , Active oxygen Physiological effect , Aromaticity (Chemistry) , Tetrapyrroles , Magnetic circular dichroism , Corroles , Chlorins , Photodynamic antimicrobial chemotherapy (PACT)
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/10962/188843 , vital:44791
- Description: In photodynamic therapy (PDT), the activation of light-sensitive drugs in tumour cells produces reactive singlet oxygen species, which cause tumour destruction through a cascade of biochemical reactions. Over the years, the wavelength of activation has been shown to be a critical factor in the penetration of light. Hence the properties of photosensitiser dyes in this context shape their ability to treat deep-seated tumours. In this study, the synthesis, structural characterisation and photophysicochemical properties of a series of Sn(IV) porphyrins with meso-methylthiophenyl rings that have been prepared to study their PDT and photodynamic antimicrobial chemotherapy (PACT) activity properties are reported. The series of Sn(IV) complexes is comprised of a porphyrin (1-Sn), a corrole (2-Sn), a chlorin (3-Sn) and an N-confused porphyrin (4-Sn). Herein, the low symmetry Sn(IV) porphyrin derivatives are shown to have excellent singlet oxygen generation capabilities, and lifetimes of the triplet excited states were in the microsecond range. For example, 4-Sn had a singlet oxygen quantum yield (ФΔ) and an excited triplet state lifetime (τT) of 0.88 and 27 μs, respectively. The complexes were studied using UV-visible and magnetic circular dichroism (MCD) spectroscopies. Interestingly, the positive-to-negative sign sequences of the Faraday B0 terms of 2-Sn and 3-Sn reveal that the structural modifications involved break the degeneracy of the MOs derived from the 1eg* LUMO of the porphyrin 1-Sn. In contrast, a conventional negative-to-positive sign sequence is observed for 4-Sn, since the confusion of a pyrrole moiety also results in a large separation of the 1a1u and 1a2u MOs of the porphyrin 1-Sn that are derived from the HOMO of a C16H162−parent hydrocarbon perimeter. The trends in the electronic structures of the Sn(IV) complexes were further investigated through a series of time-dependent density functional theory calculations, so that the suitability of the different types of complex for use in singlet oxygen applications could be further explored. During in vitro photodynamic antimicrobial chemotherapy (PACT) studies, chlorin derivative 3-Sn had the highest activity towards S. aureus and E. coli with log10 reductions of 10.5 and 8.74, respectively. The unusually high activity of 3-Sn against E.coli suggests that the interaction of neutral photosensitisers with gram-negativebacteria is more complex than previously understood. Anti-cancer PDT studies demonstrated that the photosensitisers had negligible dark cytotoxicity. Upon photoirradiation, the Sn(IV) complexes consistently exhibited IC50 values lower than 15 μM against MCF-7 adenocarcinoma cells. An IC50 value of 1.4 μM for 4-Sn after activation at the deep-red region of the spectrum demonstrates that complexes of this type merit further in-depth investigation. The results provide evidence that the low-symmetry Sn(IV) chlorins and N-confused porphyrins merit further in-depth study for use in singlet oxygen applications. , Thesis (MSc) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10
The effects of a lion (Panthera Leo) re-introduction on a resident cheetah (Acinonyx Jubatus) population In Mountain Zebra National Park, Eastern Cape, South Africa
- Authors: Van de Vyver, Daniel
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7420 , vital:21259
- Description: The global decline of large (> 10 kg) carnivores has resulted in a variety of conservation measures being put into practice to prevent extinctions. The establishment of predator-proof fences around protected areas has been a successful tool for reducing human-predator conflict. Furthermore, the re-introduction of large carnivores into small (< 1 000 km²), enclosed reserves has aided in the conservation of many species. Cheetahs (Acinonyx jubatus) and lions (Panthera leo) have benefitted from such re-introductions. The re-introduction of cheetahs before lions into the Mountain Zebra National Park (MZNP) in the Eastern Cape Province of South Africa provided a unique opportunity to study the effects of lions on an already established cheetah population. Spatial data were downloaded remotely from GPS collared individuals (n=4) and cheetah kill data were collected using the GPS cluster method before (2012-2013) and after (2013-2014) the lion (n=3) re-introduction. The same methods were used for lion kill data collection once they had been re-introduced. In general, cheetah home range size did not change after the lion re-introduction. Cheetahs selected areas with a combination of open and closed vegetation covers, while lions selected either open or closed areas of vegetation covers. In addition, as vegetation cover became thicker, the presence of cheetahs decreased. The cheetahs preyed upon seven species before and 11 species after the lion re-introduction. Medium sized prey comprised the bulk of the cheetah diet with kudu (Tragelaphus strepsiceros) and springbok (Antidorcas marsupialis) being the preferred species both before and after the lion re-introduction. The lion diets consisted of medium to large sized prey, with the male lions selecting eland (Tragelaphus oryx) and buffalo (Syncerus caffer) and the lioness selecting red hartebeest (Alcelaphus buselaphus). The cheetahs had no significant dietary overlap with the lions and there was only one record of kleptoparasitism. The results of my study indicate that cheetahs are able to co-exist with lions when lions are at low densities in an enclosed reserve. The cheetahs did not experience landscape-level displacement because they made fine-scale adjustments to avoid lions within their environment. This adaptability may have important management implications for future re-introductions of cheetahs into enclosed game reserves.
- Full Text:
- Date Issued: 2017
- Authors: Van de Vyver, Daniel
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7420 , vital:21259
- Description: The global decline of large (> 10 kg) carnivores has resulted in a variety of conservation measures being put into practice to prevent extinctions. The establishment of predator-proof fences around protected areas has been a successful tool for reducing human-predator conflict. Furthermore, the re-introduction of large carnivores into small (< 1 000 km²), enclosed reserves has aided in the conservation of many species. Cheetahs (Acinonyx jubatus) and lions (Panthera leo) have benefitted from such re-introductions. The re-introduction of cheetahs before lions into the Mountain Zebra National Park (MZNP) in the Eastern Cape Province of South Africa provided a unique opportunity to study the effects of lions on an already established cheetah population. Spatial data were downloaded remotely from GPS collared individuals (n=4) and cheetah kill data were collected using the GPS cluster method before (2012-2013) and after (2013-2014) the lion (n=3) re-introduction. The same methods were used for lion kill data collection once they had been re-introduced. In general, cheetah home range size did not change after the lion re-introduction. Cheetahs selected areas with a combination of open and closed vegetation covers, while lions selected either open or closed areas of vegetation covers. In addition, as vegetation cover became thicker, the presence of cheetahs decreased. The cheetahs preyed upon seven species before and 11 species after the lion re-introduction. Medium sized prey comprised the bulk of the cheetah diet with kudu (Tragelaphus strepsiceros) and springbok (Antidorcas marsupialis) being the preferred species both before and after the lion re-introduction. The lion diets consisted of medium to large sized prey, with the male lions selecting eland (Tragelaphus oryx) and buffalo (Syncerus caffer) and the lioness selecting red hartebeest (Alcelaphus buselaphus). The cheetahs had no significant dietary overlap with the lions and there was only one record of kleptoparasitism. The results of my study indicate that cheetahs are able to co-exist with lions when lions are at low densities in an enclosed reserve. The cheetahs did not experience landscape-level displacement because they made fine-scale adjustments to avoid lions within their environment. This adaptability may have important management implications for future re-introductions of cheetahs into enclosed game reserves.
- Full Text:
- Date Issued: 2017
Leopard population density and community attitudes towards leopards in and around Debshan Ranch, Shangani, Zimbabwe
- Authors: Nyoni, Phumuzile
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5946 , http://hdl.handle.net/10962/d1020838
- Description: Leopards (Panthera pardus) are regarded as one of the most resilient large carnivore species in the world and can persist in human dominated landscapes, areas with low prey availability nd highly fragmented habitats. However, recent evidence across much of their range reveals declining populations. In Zimbabwe, 500 Convention for the International Trade in Endangered Species (CITES) export tags are available annually for leopards as hunting trophies, despite limited accurate data on the leopard populations of the country. Moreover, when coupled with the massive land conversions under the controversial National Land Reform Programme (NLRP), leopard populations in Zimbabwe are in dire need of assessment. My study was conducted on Debshan ranch, Shangani, Zimbabwe, which is a commercial cattle (Bos indicus) ranch but also supports a high diversity of indigenous wildlife including an apparently healthy leopard population. However, the NLRP has resulted in an increase in small-holder subsistence farming communities around the ranch (the land was previously privately owned and divided into larger sub-units). This change in land-use means that both human and livestock densities have increased and the potential for human leopard conflict has increased. I estimated the leopard population density of the ranch and assessed community attitudes towards leopards in the communities surrounding the ranch. To estimate population densities, I performed spoor counts and conducted a camera trapping survey. Questionnaire interviews were used to assess community attitudes. My spoor counts provided a leopard density estimate of 13.57 leopards/100km2 compared to the camera trapping estimate of between 2.0 and 6.9 leopards/100km2. Although the high density estimate derived from the spoor counts is possible for Debshan because leopards are the apex predators and are adequately protected, potential edge effects are not yet fully understood. Thus, the more conservative estimate of 2.0 leopards/100km2, derived from the camera trapping survey, is probably more appropriate. Attitudes towards predators amongst respondents surrounding Debshan (n = 140) were neither too negative nor positive, attitude index had a mean score of 1.7 ± 3.8 (range: -7 – 10). No single predictor variable used in my analysis was able to adequately explain why the communities held these negative views. However, livestock losses were repeatedly listed by respondents as being one of the main reasons for their lack of tolerance towards predators. The density estimate of 2.0 leopards/100km2 translates to a population of 9 – 26 leopards within Debshan ranch. This density estimate is too low considering the habitat type at Debshan ranch but should be interpreted with caution as it lacks fundamental elements like age and sex ratio. Moreover, the interaction of the leopard population with the surrounding communities is currently unclear. As a precautionary measure, I recommended reducing the annual hunting quota for Debshan from five to one leopard. Future work should aim to improve the attitudes of the surrounding communities to secure broader landscapes for leopard conservation while also reconciling density estimates to fully understand the leopard population of the region.
- Full Text:
- Date Issued: 2016
- Authors: Nyoni, Phumuzile
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5946 , http://hdl.handle.net/10962/d1020838
- Description: Leopards (Panthera pardus) are regarded as one of the most resilient large carnivore species in the world and can persist in human dominated landscapes, areas with low prey availability nd highly fragmented habitats. However, recent evidence across much of their range reveals declining populations. In Zimbabwe, 500 Convention for the International Trade in Endangered Species (CITES) export tags are available annually for leopards as hunting trophies, despite limited accurate data on the leopard populations of the country. Moreover, when coupled with the massive land conversions under the controversial National Land Reform Programme (NLRP), leopard populations in Zimbabwe are in dire need of assessment. My study was conducted on Debshan ranch, Shangani, Zimbabwe, which is a commercial cattle (Bos indicus) ranch but also supports a high diversity of indigenous wildlife including an apparently healthy leopard population. However, the NLRP has resulted in an increase in small-holder subsistence farming communities around the ranch (the land was previously privately owned and divided into larger sub-units). This change in land-use means that both human and livestock densities have increased and the potential for human leopard conflict has increased. I estimated the leopard population density of the ranch and assessed community attitudes towards leopards in the communities surrounding the ranch. To estimate population densities, I performed spoor counts and conducted a camera trapping survey. Questionnaire interviews were used to assess community attitudes. My spoor counts provided a leopard density estimate of 13.57 leopards/100km2 compared to the camera trapping estimate of between 2.0 and 6.9 leopards/100km2. Although the high density estimate derived from the spoor counts is possible for Debshan because leopards are the apex predators and are adequately protected, potential edge effects are not yet fully understood. Thus, the more conservative estimate of 2.0 leopards/100km2, derived from the camera trapping survey, is probably more appropriate. Attitudes towards predators amongst respondents surrounding Debshan (n = 140) were neither too negative nor positive, attitude index had a mean score of 1.7 ± 3.8 (range: -7 – 10). No single predictor variable used in my analysis was able to adequately explain why the communities held these negative views. However, livestock losses were repeatedly listed by respondents as being one of the main reasons for their lack of tolerance towards predators. The density estimate of 2.0 leopards/100km2 translates to a population of 9 – 26 leopards within Debshan ranch. This density estimate is too low considering the habitat type at Debshan ranch but should be interpreted with caution as it lacks fundamental elements like age and sex ratio. Moreover, the interaction of the leopard population with the surrounding communities is currently unclear. As a precautionary measure, I recommended reducing the annual hunting quota for Debshan from five to one leopard. Future work should aim to improve the attitudes of the surrounding communities to secure broader landscapes for leopard conservation while also reconciling density estimates to fully understand the leopard population of the region.
- Full Text:
- Date Issued: 2016
'Rich man poor man': inter-household and community factors influencing the use of wild plant resources amongst rural households in South Africa
- Cocks, Michelle L, Bangay, Lindsey, Shackleton, Charlie M, Wiersum, K Freerk
- Authors: Cocks, Michelle L , Bangay, Lindsey , Shackleton, Charlie M , Wiersum, K Freerk
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141211 , vital:37953 , DOI: 10.3843/SusDev.15.3:3
- Description: Biodiversity is recognised as an integral part of people's daily livelihoods. This study therefore aims to understand the use of NTFPs at an intricate level by determining what role these resources fulfil in six rural villages and 1011 households' livelihoods. It examines how the use of NTFPs are influenced by intra-household variables, such as wealth and gender, and inter-community variables, such as accessibility to the natural resource. The results reveal that approximately 4453 kg of wild material is used annually per household, of which 1598 kg is used for cultural purposes. The influence of vegetation type and differences between villages are statistically more significant than inter-household variables. At an inter-household level, an increase in the financial status of households did not result in a decrease in the use of natural resources, nor in the quantity of material used.
- Full Text:
- Date Issued: 2010
- Authors: Cocks, Michelle L , Bangay, Lindsey , Shackleton, Charlie M , Wiersum, K Freerk
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141211 , vital:37953 , DOI: 10.3843/SusDev.15.3:3
- Description: Biodiversity is recognised as an integral part of people's daily livelihoods. This study therefore aims to understand the use of NTFPs at an intricate level by determining what role these resources fulfil in six rural villages and 1011 households' livelihoods. It examines how the use of NTFPs are influenced by intra-household variables, such as wealth and gender, and inter-community variables, such as accessibility to the natural resource. The results reveal that approximately 4453 kg of wild material is used annually per household, of which 1598 kg is used for cultural purposes. The influence of vegetation type and differences between villages are statistically more significant than inter-household variables. At an inter-household level, an increase in the financial status of households did not result in a decrease in the use of natural resources, nor in the quantity of material used.
- Full Text:
- Date Issued: 2010
Perceptions of Selected Stakeholders on the Use of Tablets for University Teaching
- Simon Christopher Fernandez, Kuttickattu John Mammen
- Authors: Simon Christopher Fernandez , Kuttickattu John Mammen
- Date: 2020
- Language: English
- Type: Journal article
- Identifier: http://hdl.handle.net/11260/4300 , vital:44090
- Full Text:
- Authors: Simon Christopher Fernandez , Kuttickattu John Mammen
- Date: 2020
- Language: English
- Type: Journal article
- Identifier: http://hdl.handle.net/11260/4300 , vital:44090
- Full Text:
The effect of tulbaghia violacea plant extract on the growth of aspergillus species
- Authors: Belewa, Xoliswa Vuyokazi
- Date: 2009
- Subjects: Plant products , Plant extracts , Traditional medicine
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10315 , http://hdl.handle.net/10948/d1008186 , Plant products , Plant extracts , Traditional medicine
- Description: Traditional medicine has become an important part of healthcare worldwide. It is estimated that about 25 percent of prescribed medicines contain plant products or active compounds derived from plants. In South Africa, traditional medicine forms part of the culture and tradition of most communities. Garlic compounds have been shown to have a variety of antimicrobial properties. Amongst these are antifungal, antibacterial, antiviral and anti protozoal activities. Allicin and its breakdown products have been shown to be the main active compounds which possess these properties. Tulbaghia violacea has been used for the treatment of a variety of illnesses including asthma, fever, oesophageal cancer, constipation and hypertension. This study investigated the antifungal nature of T.violacea on the morphology, spore germination and lipid synthesis of Aspergillus flavus and Aspergillus parasiticus. The results of this study showed that the plant extract inhibited A. flavus growth at a minimal inhibitory concentration of 15mg/ml and was fungicidal at 20mg/ml and above. A. parasiticus was not inhibited at 25mg/ml indicating resistance to the inhibitory component of the plant extract. A measure of metabolic activity using the XTT assay showed reduced metabolic activity in the presence of increasing concentrations of the plant extract. Higher extract concentrations resulted in higher percentage inhibition of fungal growth for both fungal species with up to 98 percent inhibition being observed for the highest extract concentrations for both fungi. Germination was also delayed in the presence of 15mg/ml plant extract concentration by up to 60hr for A. flavus and 48hr for A. parasititcus. The TEM results showed increased thickening of the cell wall with higher extract concentrations. The thickening was greater for A. flavus than for A. parasiticus. Cell wall thickening may be the reason for the delay in germination in both species. Lipid production was reduced in the presence of plant extracts when compared to the control. The plant extracts inhibited triglyceride production at 15mg/ml for both A. flavus and A. parasiticus. The results therefore indicate that T. violacea extracts are antifungal and probably affect germination through interactions with the cell wall. It is possible that the extract affects lipid production in Aspergillus species.
- Full Text:
- Date Issued: 2009
- Authors: Belewa, Xoliswa Vuyokazi
- Date: 2009
- Subjects: Plant products , Plant extracts , Traditional medicine
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10315 , http://hdl.handle.net/10948/d1008186 , Plant products , Plant extracts , Traditional medicine
- Description: Traditional medicine has become an important part of healthcare worldwide. It is estimated that about 25 percent of prescribed medicines contain plant products or active compounds derived from plants. In South Africa, traditional medicine forms part of the culture and tradition of most communities. Garlic compounds have been shown to have a variety of antimicrobial properties. Amongst these are antifungal, antibacterial, antiviral and anti protozoal activities. Allicin and its breakdown products have been shown to be the main active compounds which possess these properties. Tulbaghia violacea has been used for the treatment of a variety of illnesses including asthma, fever, oesophageal cancer, constipation and hypertension. This study investigated the antifungal nature of T.violacea on the morphology, spore germination and lipid synthesis of Aspergillus flavus and Aspergillus parasiticus. The results of this study showed that the plant extract inhibited A. flavus growth at a minimal inhibitory concentration of 15mg/ml and was fungicidal at 20mg/ml and above. A. parasiticus was not inhibited at 25mg/ml indicating resistance to the inhibitory component of the plant extract. A measure of metabolic activity using the XTT assay showed reduced metabolic activity in the presence of increasing concentrations of the plant extract. Higher extract concentrations resulted in higher percentage inhibition of fungal growth for both fungal species with up to 98 percent inhibition being observed for the highest extract concentrations for both fungi. Germination was also delayed in the presence of 15mg/ml plant extract concentration by up to 60hr for A. flavus and 48hr for A. parasititcus. The TEM results showed increased thickening of the cell wall with higher extract concentrations. The thickening was greater for A. flavus than for A. parasiticus. Cell wall thickening may be the reason for the delay in germination in both species. Lipid production was reduced in the presence of plant extracts when compared to the control. The plant extracts inhibited triglyceride production at 15mg/ml for both A. flavus and A. parasiticus. The results therefore indicate that T. violacea extracts are antifungal and probably affect germination through interactions with the cell wall. It is possible that the extract affects lipid production in Aspergillus species.
- Full Text:
- Date Issued: 2009
Assessing the outcomes and consequences of large carnivore reintroductions to the Eastern Cape, South Africa
- Banasiak, Natalia Matgorzata
- Authors: Banasiak, Natalia Matgorzata
- Date: 2017
- Subjects: Carnivores -- Reintroduction , Wildlife reintroduction
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/11963 , vital:27011
- Description: Reintroduction is a potentially powerful tool available to conservationists to cope with species population declines. Nonetheless, it is poorly understood and past reviews tend to indicate poor results. Reintroduction, under the sensu stricto IUCN definition, must have a primary objective of conservation; however species can be released to sites in their indigenous range (reintroduction sensu lato) to meet other objectives. The outcomes of these reintroductions s.l need to be assessed to determine how effectively they achieve their varied objectives. A Web of Science review revealed that only 32.1% of 131 publications on reintroduction provided clearly defined success criteria. Using economic, ecological, conservation and problem animal management objectives as reintroduction s.l. drivers, I developed context-dependent success definitions for each objective to use in reintroduction outcome assessments. These success criteria were then used to assess the reintroductions s.l. of large carnivores, namely lion, leopard, cheetah, African wild dog, spotted hyaena, and brown hyaena, to 16 private- and state-owned reserves in the Eastern Cape Province, South Africa. Ecotourism and ecological restoration were the most common objectives for the reintroduction of top predators to these reserves. Overall the reintroductions of large carnivores have been successful in meeting their objectives. Only African wild dogs have failed to establish in the province. Causes of objective-specific failures for the other species in some reserves included introductions of same-sex populations, lack of breeding events and changes in reserve management objectives. Assessments for leopard and brown hyaena were inconclusive due to lack of monitoring data. The reintroduction of large carnivores to the Eastern Cape Province has also resulted in the emergence of human-carnivore conflict on neighbouring properties. Carnivores have reportedly escaped from 8 reserves (61.5% of reserves) in the Eastern Cape. A total of 75 conflict events on 68 neighbouring properties (36.7% of neighbouring properties) have been reported. There is a major gap in research around conflict resulting from carnivore reintroductions and future research is required to fully understand the situation in the province in order to develop effective mitigation methods. An adaptive management approach to reintroductions is encouraged to improve monitoring and ensure reintroductions continue to meet their objectives. Furthermore, emerging consequences, such as human-wildlife conflict, and related mitigation strategies should be incorporated into management of reintroduced populations. Communities surrounding reintroduction sites should be educated on lifting baselines where conflict-causing species are recovering to ensure continued success of reintroduction undertakings. National management plans should be developed for all large carnivore species to improve the conservation value of small, fenced reserves that are typical of South African conservation, through a managed metapopulation approach. Management plans should include social, political, and economic factors that can influence the success of reintroductions and ultimate conservation outcomes.
- Full Text:
- Date Issued: 2017
- Authors: Banasiak, Natalia Matgorzata
- Date: 2017
- Subjects: Carnivores -- Reintroduction , Wildlife reintroduction
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/11963 , vital:27011
- Description: Reintroduction is a potentially powerful tool available to conservationists to cope with species population declines. Nonetheless, it is poorly understood and past reviews tend to indicate poor results. Reintroduction, under the sensu stricto IUCN definition, must have a primary objective of conservation; however species can be released to sites in their indigenous range (reintroduction sensu lato) to meet other objectives. The outcomes of these reintroductions s.l need to be assessed to determine how effectively they achieve their varied objectives. A Web of Science review revealed that only 32.1% of 131 publications on reintroduction provided clearly defined success criteria. Using economic, ecological, conservation and problem animal management objectives as reintroduction s.l. drivers, I developed context-dependent success definitions for each objective to use in reintroduction outcome assessments. These success criteria were then used to assess the reintroductions s.l. of large carnivores, namely lion, leopard, cheetah, African wild dog, spotted hyaena, and brown hyaena, to 16 private- and state-owned reserves in the Eastern Cape Province, South Africa. Ecotourism and ecological restoration were the most common objectives for the reintroduction of top predators to these reserves. Overall the reintroductions of large carnivores have been successful in meeting their objectives. Only African wild dogs have failed to establish in the province. Causes of objective-specific failures for the other species in some reserves included introductions of same-sex populations, lack of breeding events and changes in reserve management objectives. Assessments for leopard and brown hyaena were inconclusive due to lack of monitoring data. The reintroduction of large carnivores to the Eastern Cape Province has also resulted in the emergence of human-carnivore conflict on neighbouring properties. Carnivores have reportedly escaped from 8 reserves (61.5% of reserves) in the Eastern Cape. A total of 75 conflict events on 68 neighbouring properties (36.7% of neighbouring properties) have been reported. There is a major gap in research around conflict resulting from carnivore reintroductions and future research is required to fully understand the situation in the province in order to develop effective mitigation methods. An adaptive management approach to reintroductions is encouraged to improve monitoring and ensure reintroductions continue to meet their objectives. Furthermore, emerging consequences, such as human-wildlife conflict, and related mitigation strategies should be incorporated into management of reintroduced populations. Communities surrounding reintroduction sites should be educated on lifting baselines where conflict-causing species are recovering to ensure continued success of reintroduction undertakings. National management plans should be developed for all large carnivore species to improve the conservation value of small, fenced reserves that are typical of South African conservation, through a managed metapopulation approach. Management plans should include social, political, and economic factors that can influence the success of reintroductions and ultimate conservation outcomes.
- Full Text:
- Date Issued: 2017
Predicting reintroduction outcomes: assessing the feasibility of reintroducing African wild dog to a small protected area
- Authors: Vogel, John Thomas
- Date: 2018
- Subjects: African wild dog , Wild dogs -- South Africa Wild dogs -- Conservation -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/36464 , vital:33947
- Description: Large mammalian carnivores have experienced significant contractions in population sizes and geographical ranges. The conservation of large carnivores is crucially important, particularly due to their vulnerability to extinction and their functional significance and ability to structure ecosystems. Due to an expanding human footprint, large carnivores are increasingly subject to modified and spatially constrained habitats. A growing debate exists as to how to conserve and coexist with large carnivores in an anthropogenically induced environment. Reintroduction, as a conservation tool to restore locally extirpated large carnivores to portions of their former ranges is increasingly being applied. However, in South Africa, habitat to support large carnivores remain small and non-contiguous. Food is a fundamental ecological requirement to sustain reintroduced large carnivores. Therefore, an understanding of large predator foraging patterns can be informative in the context of how the predator species influences and utilises a novel ecosystem. We investigated the foraging behaviour of reintroduced African wild dog (Lycaon pictus) at five small protected areas in KwaZulu-Natal, South Africa. Wild dog utilised 16 prey species, albeit they primarily used nyala (Tragelaphus angasii) and impala (Aepyceros melampus) which collectively form 75 % of their diet. Only nyala was significantly preferred, suggesting that this prey species is used in greater proportion to their abundance. As wild dogs are social cooperative hunters, we tested whether wild dog pack size was correlated to prey mass selection. There was no evidence to suggest that larger packs use larger prey. However, the mean wild dog pack size in our sample sites, was relatively smaller than those encountered elsewhere. Furthermore, wild dog have been shown to modify their hunting behaviour in the presence of wildlife-proof fencing, by using fences to aid in the capture of larger prey species than would innately occur. We compared the prey mass of wild dog kills in relation to proximity of these hard boundaries. Despite the affinity towards kills occurring within 200 m of fences, the upward bias caused by fences on prey mass selection was inconsistent across sample sites. The relatively small size of wild dogs makes them particularly vulnerable to competition. As the energetic output of wild dog is high, interspecific competition can increase foraging costs. The reintroduction of large carnivores to small artificially induced systems may be a contentious issue as resources available to support large carnivores are expected to be relatively more finite. We compared both the potential inter- and intraspecific dietary niche dimensions of an intact large carnivore guild in context of a wild dog reintroduction. We determined cheetah (Acinonyx jubatus), leopard (Panthera pardus), and lion (Panthera leo) prey composition, diet breadth, overlap, prey preference and predicted the density of an intact large carnivore guild in a novel landscape. Further, we compared the foraging behaviour of these large carnivores to that of wild dog. Our findings suggest that large African carnivores in small protected areas are subject to a considerable dietary niche overlap. Wild dog and cheetah, particularly reproductive females with dependent offspring, displayed the greatest potential for dietary overlap and subsequent competition. Leopard and lion at the population species level exhibited greater degrees of foraging plasticity. Lion displayed a contrasting prey species preference to sympatric predators as they selected for prey items frequently avoided by cheetah, leopard and wild dog. The proposed wild dog reintroduction site is expected to sustain seven wild dog based on the availability of preferred prey biomass. However, the reintroduction of wild dog to the small protected area is expected to have negative lateral trophic influences on other species of conservation concern. This should be of vital importance to management of the protected area. As the influence of competition in food-web and population dynamics, particularly in resource poor environments may be profound, our research highlights the need to assess the influence of competitive forces in structuring and restoring large predators to portions of their historical range.
- Full Text:
- Date Issued: 2018
- Authors: Vogel, John Thomas
- Date: 2018
- Subjects: African wild dog , Wild dogs -- South Africa Wild dogs -- Conservation -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/36464 , vital:33947
- Description: Large mammalian carnivores have experienced significant contractions in population sizes and geographical ranges. The conservation of large carnivores is crucially important, particularly due to their vulnerability to extinction and their functional significance and ability to structure ecosystems. Due to an expanding human footprint, large carnivores are increasingly subject to modified and spatially constrained habitats. A growing debate exists as to how to conserve and coexist with large carnivores in an anthropogenically induced environment. Reintroduction, as a conservation tool to restore locally extirpated large carnivores to portions of their former ranges is increasingly being applied. However, in South Africa, habitat to support large carnivores remain small and non-contiguous. Food is a fundamental ecological requirement to sustain reintroduced large carnivores. Therefore, an understanding of large predator foraging patterns can be informative in the context of how the predator species influences and utilises a novel ecosystem. We investigated the foraging behaviour of reintroduced African wild dog (Lycaon pictus) at five small protected areas in KwaZulu-Natal, South Africa. Wild dog utilised 16 prey species, albeit they primarily used nyala (Tragelaphus angasii) and impala (Aepyceros melampus) which collectively form 75 % of their diet. Only nyala was significantly preferred, suggesting that this prey species is used in greater proportion to their abundance. As wild dogs are social cooperative hunters, we tested whether wild dog pack size was correlated to prey mass selection. There was no evidence to suggest that larger packs use larger prey. However, the mean wild dog pack size in our sample sites, was relatively smaller than those encountered elsewhere. Furthermore, wild dog have been shown to modify their hunting behaviour in the presence of wildlife-proof fencing, by using fences to aid in the capture of larger prey species than would innately occur. We compared the prey mass of wild dog kills in relation to proximity of these hard boundaries. Despite the affinity towards kills occurring within 200 m of fences, the upward bias caused by fences on prey mass selection was inconsistent across sample sites. The relatively small size of wild dogs makes them particularly vulnerable to competition. As the energetic output of wild dog is high, interspecific competition can increase foraging costs. The reintroduction of large carnivores to small artificially induced systems may be a contentious issue as resources available to support large carnivores are expected to be relatively more finite. We compared both the potential inter- and intraspecific dietary niche dimensions of an intact large carnivore guild in context of a wild dog reintroduction. We determined cheetah (Acinonyx jubatus), leopard (Panthera pardus), and lion (Panthera leo) prey composition, diet breadth, overlap, prey preference and predicted the density of an intact large carnivore guild in a novel landscape. Further, we compared the foraging behaviour of these large carnivores to that of wild dog. Our findings suggest that large African carnivores in small protected areas are subject to a considerable dietary niche overlap. Wild dog and cheetah, particularly reproductive females with dependent offspring, displayed the greatest potential for dietary overlap and subsequent competition. Leopard and lion at the population species level exhibited greater degrees of foraging plasticity. Lion displayed a contrasting prey species preference to sympatric predators as they selected for prey items frequently avoided by cheetah, leopard and wild dog. The proposed wild dog reintroduction site is expected to sustain seven wild dog based on the availability of preferred prey biomass. However, the reintroduction of wild dog to the small protected area is expected to have negative lateral trophic influences on other species of conservation concern. This should be of vital importance to management of the protected area. As the influence of competition in food-web and population dynamics, particularly in resource poor environments may be profound, our research highlights the need to assess the influence of competitive forces in structuring and restoring large predators to portions of their historical range.
- Full Text:
- Date Issued: 2018
Incorporating prey demographics and predator social structure into prey selection and carrying capacity estimates for cheetah
- Authors: Clements, Hayley Susan
- Date: 2012
- Subjects: Carnivorous animals , Cheetah
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10754 , http://hdl.handle.net/10948/d1018606
- Description: There is a need for a refined understanding of large carnivore prey preference and carrying capacity (K). To date, K estimates for large carnivores have been developed from predictions of carnivore diet at a prey and predator species-level. These predictions therefore assume that all social classes within a carnivore species display similar prey preferences and that all demographic classes within a prey species are equally preferred or avoided. The objective of this study was to investigate the importance of including prey demographics and carnivore social class in carnivore diet descriptions and thereby K estimates, using cheetah Acinonyx jubatus as a study species. It was predicted that prey sex, prey age and cheetah social class influence cheetah prey preferences, when they influence the risk and ease of prey capture, and that their inclusion in a K model would improve its predictive strength. Based on an analysis of 1290 kills from South Africa, male coalition cheetah were found to prefer a broader weight range of prey than solitary cheetah. Prey demographics further influenced cheetah prey preference, when it corresponded to differences in prey size and the presence of horns. The current species-level K regression model for cheetah is based on preferred prey and thus omits highly abundant antelope that often comprise the majority of the diet, an artefact of the way in which preferences are calculated. A refinement of the species-level K regression model, to account for prey demographic- and cheetah social class-level differences in diet and the biomass of accessible prey (defined in this study as all non-avoided prey) instead of just preferred prey, doubled the predictive strength of the K model. Because group-hunting enabled predation on a broader weight range of prey, cheetah K was influenced by the ratio of male coalition cheetah to solitary cheetah in the population. The refined K regression model is derived from ecosystems supporting an intact carnivore guild. A mechanistic approach to estimating K, based on Caughley‟s (1977) maximum sustainable yield model, therefore better predicted cheetah K in systems devoid of lion Panthera leo and African wild dog Lycaon pictus, which were found to suppress cheetah density. This study improves our understanding of the relationships between prey demographics, cheetah social classes and intra-guild competition in determining cheetah prey preferences and K. This study therefore paves the way for similar work on other large carnivores.
- Full Text:
- Date Issued: 2012
- Authors: Clements, Hayley Susan
- Date: 2012
- Subjects: Carnivorous animals , Cheetah
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10754 , http://hdl.handle.net/10948/d1018606
- Description: There is a need for a refined understanding of large carnivore prey preference and carrying capacity (K). To date, K estimates for large carnivores have been developed from predictions of carnivore diet at a prey and predator species-level. These predictions therefore assume that all social classes within a carnivore species display similar prey preferences and that all demographic classes within a prey species are equally preferred or avoided. The objective of this study was to investigate the importance of including prey demographics and carnivore social class in carnivore diet descriptions and thereby K estimates, using cheetah Acinonyx jubatus as a study species. It was predicted that prey sex, prey age and cheetah social class influence cheetah prey preferences, when they influence the risk and ease of prey capture, and that their inclusion in a K model would improve its predictive strength. Based on an analysis of 1290 kills from South Africa, male coalition cheetah were found to prefer a broader weight range of prey than solitary cheetah. Prey demographics further influenced cheetah prey preference, when it corresponded to differences in prey size and the presence of horns. The current species-level K regression model for cheetah is based on preferred prey and thus omits highly abundant antelope that often comprise the majority of the diet, an artefact of the way in which preferences are calculated. A refinement of the species-level K regression model, to account for prey demographic- and cheetah social class-level differences in diet and the biomass of accessible prey (defined in this study as all non-avoided prey) instead of just preferred prey, doubled the predictive strength of the K model. Because group-hunting enabled predation on a broader weight range of prey, cheetah K was influenced by the ratio of male coalition cheetah to solitary cheetah in the population. The refined K regression model is derived from ecosystems supporting an intact carnivore guild. A mechanistic approach to estimating K, based on Caughley‟s (1977) maximum sustainable yield model, therefore better predicted cheetah K in systems devoid of lion Panthera leo and African wild dog Lycaon pictus, which were found to suppress cheetah density. This study improves our understanding of the relationships between prey demographics, cheetah social classes and intra-guild competition in determining cheetah prey preferences and K. This study therefore paves the way for similar work on other large carnivores.
- Full Text:
- Date Issued: 2012
Photodynamic therapy for the Developing World
- Authors: Songca, S P
- Date: 2010
- Subjects: Skin -- Diseases -- Photochemotherapy Phototherapy Skin -- Diseases -- Treatment
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/11260/1056 , vital:30559
- Description: This article contains some of the contributing works to the founding of the prestigious journal Tetrahedron and it describes the total synthesis of chlorophyll-a starting from Knorr's pyrrole synthesis and includes more than forty six stages required to reach the target molecule.
- Full Text:
- Date Issued: 2010
- Authors: Songca, S P
- Date: 2010
- Subjects: Skin -- Diseases -- Photochemotherapy Phototherapy Skin -- Diseases -- Treatment
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/11260/1056 , vital:30559
- Description: This article contains some of the contributing works to the founding of the prestigious journal Tetrahedron and it describes the total synthesis of chlorophyll-a starting from Knorr's pyrrole synthesis and includes more than forty six stages required to reach the target molecule.
- Full Text:
- Date Issued: 2010
The stock identification of the Cape horse mackerel, Trachurus trachurus capensis (Pisces: Carangidae)
- Authors: Naish, Kerry-Ann
- Date: 1990
- Subjects: Carangidae -- Identification , Trachurus trachurus -- Identification , Carangidae -- South Africa , Trachurus trachurus -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5320 , http://hdl.handle.net/10962/d1005165 , Carangidae -- Identification , Trachurus trachurus -- Identification , Carangidae -- South Africa , Trachurus trachurus -- South Africa
- Description: Three stocks of the Cape horse mackerel, Trachurus trachurus capensis, have been recognised in the ICSEAF convention region off southern Africa (Figure 1) on the basis of catch distribution and biological analyses. They were identified as being off Namibia (ICSEAF Divisions 1 . 3 and 1.4), off the West Coast of South Africa (Div. 1.6) and off the South Coast (Div. 2.1 and 2.2). Recently, speculation as to the accuracy of the classification of the South African populations has arisen. The aim of this study was to determine the number of stocks In Divisions 1.6, 2.1 and 2.2, using methodology which assessed the spatial and temporal nature and the phenotypic and genotypic characteristics of the species. The distribution of horse mackerel was evaluated by studying the trends in catch data and length frequency distributions obtained from the demersal industry during 1986 to 1988 and from the demersal biomass cruises in 1987 and 1988. Adult fish, found in Div. 2.1 and 2.2, probably migrated; during the months in which horse mackerel were expected to spawn, CPUE values were higher over the central Agulhas Bank than in the east of the study region. During the quiescent period, catches and numbers were higher in the latter region. Juvenile horse mackerel were found in the nursery areas utilised by pelagic fish and it is likely that they were transported northward from the Agulhas Bank. A decrease in biomass of individuals in Div. 1.5 indicated a separation between a northern and a southern population. Analyses of the phenotype, or epigenetic characters, of horse mackerel were used as a further test of stock integrity. Monthly samples were drawn from Div. 1.6, 2.1 and 2.2 during May 1988 to June, 1989. Comparisons for the values obtained from growth, length-at-50%-maturity and the season of otolith ring formation from each region showed no significant variation in the phenotype. Morphometric analysis proved inconclusive. Monthly gonadosomatic indices show that fish south of the Orange River share the same spawning season. Reports from the literature show that horse mackerel in the latter region differ from those of northern Namibia in spawning season, age-at-50%-maturity and season of otolith ring formation. The genetic structure of the populations of horse mackerel was evaluated by means of a restriction enzyme analysis of the Mitochondrial DNA of 37 fish collected from Divisions 1.4, 1.5, 1.6, 2.1 and 2.2. Two composite genotypes of horse mackerel were found; one belonging to fish in Div. 1.4 and one to fish in Div. 1.6, 2.1 and 2.2. The genetic distance between the two genotypes, 0.07, was the expected distance between two populations at a subspecies level. Fish in Div. 1.5 consisted of both genotypes and may be a region of mixing between the two populations. The interpretation of results was cautioned; prevlous work has shown that the migration of a small number of individuals between two stocks can be expected to maintain a low variation between the populations. In concluding, it was recommended that the horse mackerel be managed as two stocks, one in Div. 1.3 and 1.4 and one in Div. 1.6, 2.1 and 2.2
- Full Text:
- Date Issued: 1990
- Authors: Naish, Kerry-Ann
- Date: 1990
- Subjects: Carangidae -- Identification , Trachurus trachurus -- Identification , Carangidae -- South Africa , Trachurus trachurus -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5320 , http://hdl.handle.net/10962/d1005165 , Carangidae -- Identification , Trachurus trachurus -- Identification , Carangidae -- South Africa , Trachurus trachurus -- South Africa
- Description: Three stocks of the Cape horse mackerel, Trachurus trachurus capensis, have been recognised in the ICSEAF convention region off southern Africa (Figure 1) on the basis of catch distribution and biological analyses. They were identified as being off Namibia (ICSEAF Divisions 1 . 3 and 1.4), off the West Coast of South Africa (Div. 1.6) and off the South Coast (Div. 2.1 and 2.2). Recently, speculation as to the accuracy of the classification of the South African populations has arisen. The aim of this study was to determine the number of stocks In Divisions 1.6, 2.1 and 2.2, using methodology which assessed the spatial and temporal nature and the phenotypic and genotypic characteristics of the species. The distribution of horse mackerel was evaluated by studying the trends in catch data and length frequency distributions obtained from the demersal industry during 1986 to 1988 and from the demersal biomass cruises in 1987 and 1988. Adult fish, found in Div. 2.1 and 2.2, probably migrated; during the months in which horse mackerel were expected to spawn, CPUE values were higher over the central Agulhas Bank than in the east of the study region. During the quiescent period, catches and numbers were higher in the latter region. Juvenile horse mackerel were found in the nursery areas utilised by pelagic fish and it is likely that they were transported northward from the Agulhas Bank. A decrease in biomass of individuals in Div. 1.5 indicated a separation between a northern and a southern population. Analyses of the phenotype, or epigenetic characters, of horse mackerel were used as a further test of stock integrity. Monthly samples were drawn from Div. 1.6, 2.1 and 2.2 during May 1988 to June, 1989. Comparisons for the values obtained from growth, length-at-50%-maturity and the season of otolith ring formation from each region showed no significant variation in the phenotype. Morphometric analysis proved inconclusive. Monthly gonadosomatic indices show that fish south of the Orange River share the same spawning season. Reports from the literature show that horse mackerel in the latter region differ from those of northern Namibia in spawning season, age-at-50%-maturity and season of otolith ring formation. The genetic structure of the populations of horse mackerel was evaluated by means of a restriction enzyme analysis of the Mitochondrial DNA of 37 fish collected from Divisions 1.4, 1.5, 1.6, 2.1 and 2.2. Two composite genotypes of horse mackerel were found; one belonging to fish in Div. 1.4 and one to fish in Div. 1.6, 2.1 and 2.2. The genetic distance between the two genotypes, 0.07, was the expected distance between two populations at a subspecies level. Fish in Div. 1.5 consisted of both genotypes and may be a region of mixing between the two populations. The interpretation of results was cautioned; prevlous work has shown that the migration of a small number of individuals between two stocks can be expected to maintain a low variation between the populations. In concluding, it was recommended that the horse mackerel be managed as two stocks, one in Div. 1.3 and 1.4 and one in Div. 1.6, 2.1 and 2.2
- Full Text:
- Date Issued: 1990