Masters Degrees (Ecology)

Permanent URI for this collectionhttps://hdl.handle.net/10413/7488

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The impact of land-use change on arthropod diversity along an arid elevational gradient.
(2022) Mkhungo, S'phesihle.; Munyai, Thinandavha Caswell.; Foord, Stefan Hendrik.
Land-use change is a major threat to global biodiversity. The rapid growth of the human population has resulted in increased landscape modifications and habitat loss. The impact includes reduced species diversity, ecosystem instability, altered species interactions and altered food webs. Land-use has increased drastically in mountainous areas, mainly through agriculture and human settlements. Mountains support approximately one-third of the terrestrial diversity and host half of the global biodiversity hotspots. The high variation in habitat structure and microclimates, within short distances allows mountains to support high species diversity. This study aimed to investigate the impact of increasing land-use change, elevation, and season on selected arthropod diversity, and community composition along the Western Soutpansberg mountain range in Limpopo province of South Africa. The objectives of the study were to determine spider and ant diversity patterns along the mountain. Secondly, to determine the role of land-use, elevation, and season in structuring the diversity of both taxa. Lastly, to compare the composition of spider and ant assemblages across the various sites and identify indicator species for monitoring land-use change in the study area. A standardized pitfall trap survey was used to sample ants and spiders along an elevational transect that stretches across the southern and northern aspects of the mountain. The elevational transect (800 m a. s. l – 1700 m a. s. l) was made up of 18 sites, some of which have undergone human transformation mainly through agriculture and settlements. Sampling took place during the dry season (September 2019) and wet season (January 2020). Generalized linear mixed models with Poisson error distributions were used to determine the impact of land-use, elevation, season on spider and ant species richness and activity. Community composition was analyzed using NMDS (non-metric multidimensional scaling), PERMANOVA and ANOSIM analyses. Land-use had a positive effect on spider and ant diversity as the transformed sites had significantly higher species richness and activity for both taxa, particularly the agricultural sites and human settlement. However, species evenness was significantly lower in the transformed sites and higher in the natural sites. Species richness and activities for both taxa were highest at the low elevations. Spider diversity was higher in the dry season, but ants peaked in the wet season. Spider and ant assemblages were highly distinct between the land-use types and elevations. Ant assemblages remained similar between the seasons, while spider composition was slightly different across the two seasons. Spider and ant assemblages in the transformed sites were highly uneven which indicates a large disproportion in the number of individuals within the species found in transformed sites. It also indicates high species dominance, which is driven by the disturbance-tolerant species. One spider species, Copa flavoplumosa, was identified as an indicator species for the Eucalyptus plantations. All land-use types had an ant indicator species, which was either Monomorium damarense and/or Lepisiota sp.02 (spinosior gp.). High species dominance displayed by spider and ant assemblages in the modified habitats might have adverse effects on native and endemic communities. Because dominant and disturbance-tolerant species are likely to increase if more natural land is converted. This study was the first to investigate the impact of land-use changes at the Soutpansberg mountain range. The results indicate that landuse change had a positive effect on arthropod species richness and activity. However, species evenness was negatively affected. Although the land-use changes at Soutpansberg can increase the diversity of certain species, the potential to sustain the populations over the long term is unknown. Therefore, further assessments and monitoring of diversity in the region is recommended to understand the long-term impact of land-use and for informed decision making and strategy in conservation efforts.
Investigating the effectiveness of a simple water-purifying gadget made of Moringa oleifera seeds as the active beads.
(2023) Raphasha, Dineo Gladys.; Tsvuura, Zivanai.; Ndhlala, Ashwell Rungano.; Mbendana, Dambudzo.
Abstract available in PDF.
Evaluating multiple stressors on aquatic ecosystems in an urban environment.
(2024) Ngcobo, Nolwazi Blessed.; Downs, Colleen Thelma.
The issue of compromised aquatic ecosystems is a global dilemma; with existing and new stressors emerging, freshwater ecosystems continue to degrade tremendously. Multiple stressors exist in aquatic ecosystems, from invasive species to overexploitation of aquatic resources, habitat degradation, flow modifications and pollution. The uMsunduzi catchment in Pietermaritzburg, KwaZulu-Natal Province, South Africa, is one such stressed freshwater body. The present study was undertaken to determine the major threats to aquatic ecosystems and the possible strategies to mitigate the factors that compromise freshwater biodiversity, health, and ecological status. The first problem was to investigate the impact of anthropogenic barriers along the longitudinal pathway of the rivers. Hence, an extensive literature review on managing river barriers was conducted. This systematic review showed a need for river connectivity restoration projects in Africa, particularly in South Africa. The Northern Hemisphere countries are more advanced in restoring river connectivity by removing barriers or retrofitting fishways. A prevalence of physical barriers in the uMsunduzi catchment was found, and most barriers did not have fishways or fish passage structures. The fish communities, together with their associated habitat features, within the uMsunduzi mainstem and tributaries, were assessed to deduce which environmental factors influence the fish communities' structures in the system. There was a clear indication of a decline in species diversity and deterioration of the ecological health of the uMsunduzi catchment. Of the 18 expected fish species, according to the Freshwater Biodiversity Information System (2023), only 50% of these were caught. This is concerning, especially as the “near threatened” (IUCN status) Enteromius gurneyii (redtail barb) was not caught, and Amphilius natalensis (Natal mountain catfish) was caught once in low abundance. The uMsunduzi River had a highly deteriorated ecological integrity per the Fish Response Assessment Index (FRAI) scores, especially close and downstream of the city centre where the industrial areas are concentrated. Similarly, there is a great deal of microbial contamination, putting the uMsunduzi River in a matter of public health. There was also a significant presence of magnesium, calcium and fatty acids. In conclusion, the connectivity, ecological health and water quality of the uMsunduzi catchment were compromised, giving a clarion call for mitigation and management actions on the systems.
Effects of land restoration on the habitat integrity of rivers based on biological water quality and habitat condition assessments with a focus on the eThekwini Municipality, Durban, South Africa.
(2024) Magudu, Kholosa.; Downs, Colleen Thelma.; Burnett, Matthew James.
Riparian ecosystems are natural areas that offer an extensive range of ecosystem services. Their functionality aids in diverting and mitigating the impacts of surface water runoff, thereby reducing soil erosion. Riparian ecosystems also play an important role in sequestering nutrients and organic matter. The degradation of river systems impairs riparian ecosystem health and results in dysfunction, lack of ecosystem services provision and other deleterious effects. This study examined the effect of restoring riparian habitats across two study sites in Durban, Ethekwini Municipality, South Africa. The study aimed to a) measure and assess habitat integrity across three river systems as a result of reforestation efforts, and b) monitor the biological water quality using the Mini Stream Assessment Scoring System (MiniSASS) and the Index of Habitat Integrity indices. In addition, a systematic review was undertaken to provide an introduction and background to ecological restoration work involving freshwater ecosystems in the general South African context. The Index of Habitat Integrity and MiniSASS data were collected over ten months at two sites reforested by eThekwini Municipality, which were compared with data collected from a third river site used as the reference. Two sampling points were selected per site (namely upstream and downstream). It was predicted there would be a significant difference in MiniSASS scores between river sites under reforestation and reference sites not exposed to reforestation. However, it was found that MiniSASS and Index of Habitat Integrity scores differed between and across sites. The reference site had the highest scores. The sites with greater habitat integrity had improved ecological conditions based on macroinvertebrate responses to anthropogenic disturbances. This study highlighted the important role of naturally functioning riparian habitats in cleaning water and provides a baseline for reforestation impact monitoring, as well as informing local governance strategies for restoring degraded rivers in urban areas.
Community diversity and composition of ground-dwelling arthropods in major habitat types of the KwaZulu-Natal Sandstone Sourveld.
(2023) Mhlongo, Nokukhanya.; Tsvuura, Zivanai.; Munyai, Thinandavha Caswell.
Grasslands constitute over 25% of the global land surface and close to one-third of southern Africa. Natural and semi-natural grasslands are recognized globally for their high biodiversity value and their important contribution to the provision of ecosystem services, including provisioning services such as carbon sequestration, water catchments, and grazing for livestock and wildlife. Nonetheless, grasslands are consistently reduced and threatened by anthropogenic activities and invasive alien plants. Invasive alien plants may hinder the growth of natural vegetation by overconsumption of resources. The impact of invasive alien plants on natural vegetation may indirectly affect plant-to-animal interactions such as specialized pollination and seed dispersal syndromes which may ultimately disturb ecosystem processes. The Sandstone Sourveld in KwaZulu-Natal province of South Africa is a threatened grassland ecosystem as a result of various anthropogenic disturbances. Knowledge of arthropod response to differences in habitat types may be essential for an improved understanding of the structure and functioning of ecosystems, which is relevant for informing conservation practice. The aim of this study was to investigate the composition and diversity patterns of ground-dwelling arthropods (ants, beetles, Orthopterans, and spiders) in three habitat types (forest, intact grassland, and disturbed grassland) at Springside and Tanglewood Nature Reserves, which occur in the KwaZulu-Natal Sandstone Sourveld (KZNSS). The objectives were: (i) to document the response of the ground-dwelling arthropod community in different habitat types, (ii) to determine the impacts of seasonal change on the abundance and richness of ground-dwelling arthropods at the two sites, and (iii) to determine the correlation between the distribution of ground-dwelling arthropods and soil characteristics in the KZNSS. Ground-dwelling arthropods were sampled in Springside and Tanglewood Nature Reserves using pitfall traps in each habitat type. Soil parameters in the habitats were also assessed. Analysis of variance was used to test for differences in arthropod morphospecies richness and abundance viii across the habitat types and between seasons. The Shannon-Weiner diversity index was computed and used to compare the diversity of ground-dwelling arthropods between the two sites and among habitat types. Ground-dwelling arthropods showed varying patterns in response to habitat characteristics and the disturbance gradient at Springside and Tanglewood. Intact grassland was the most diverse habitat in both Springside and Tanglewood. In Tanglewood, the abundance of ants was greater in disturbed grassland which consisted of a variety of alien invasive shrubs, the high abundance was explained by the “intermediate disturbance hypothesis”. However, alien invasion showed more negative than positive impacts on the abundance and composition of ground-dwelling arthropods when there was a significant decrease in the abundance and composition of ants, beetles and spiders. Species richness of ants and beetles was higher in the wet than dry season whereas Orthopterans and spiders showed no significant difference between seasons. In all arthropod groups, a greater number of species were correlated to soil potassium, soil pH, and soil bulk density. Overall, the intact grassland had the highest species richness and abundance followed by the forest and lastly the disturbed grassland. The greater abundance of ants, beetles, and spiders in the pristine grasslands of KZNSS shows that there is still a need to conserve the remnants of the KZNSS vegetation. Therefore, the conservancy management is urged to consider the eradication of alien invasive plants. Future studies are recommended to consider the volant and vegetation canopy arthropods as they are all interdependent with ground-dwelling arthropods to form a whole community of arthropods in an ecosystem.
Importance of freshwater systems and eels in the uMngeni and uThukela catchments, KwaZulu-Natal, South Africa: community perspectives.
(2023) Nkomo, Mxolisi Nhlakanipho.; Downs, Colleen Thelma.
Globally, the conservation status of inland fishery resources and freshwater systems is vulnerable, threatening communities' livelihoods dependent on freshwater harvested species. Few studies have reported on the economic and cultural contributions of catadromous eels (Anguilla spp.) in southern Africa, particularly in South Africa. Beyond using freshwater systems for domestic purposes and meeting basic needs, people use rivers for socio-cultural purposes such as; cultural (cleansing), spirituality (healing), and religion (baptism). This study was undertaken to determine if human activities impact the African anguillids eel populations in the local communities of uThukela and uMngeni catchments and management areas in KwaZulu-Natal. A systematic review was conducted on global studies, with an emphasis on southern Africa, that report on the human perspective on the value of anguillid eels when in freshwater systems. In the southern African region, the available literature focused on the distribution of anguillid eels, habitat loss, and a report on the drastic decline of anguillid eels in KwaZulu-Natal's freshwaters where the Anguilla marmorata, A. mossambica, A. bengalensis, and A. bicolor occur. The studies from the northern hemisphere were rich in reports of eel harvesting (wild catches) and export, which was lacking in the southern African region. The systematic review showed a scarcity of knowledge regarding anguillid eels’ association with spirituality, spirituality, culture, and subsistence in South Africa. Secondly, people’s perceptions of the importance of eel species in freshwater fisheries were assessed using a questionnaire along water courses in the uMngeni and uThukela catchments and ecological management areas, KwaZulu-Natal. A total of 154 people were interviewed (66% males, 34% females); the majority of these participants were isiZulu-speaking, which contextualises the findings to the area of KwaZulu-Natal, uThukela and uMngeni management ii areas in particular. The fishing of eels was found in both catchments, with 74% (of the n = 102) being subsistence fishers (with only one female fisher), and 41% of these subsistence fishers specifically targeted eels. All the fishers that targeted eels depended on freshwater eel catches for income because of the relatively high demand and value. Some fishers caught and sold eels to traditional healers who used their products of medicinal products for different uses. Thirdly, the use of freshwater eels (Anguilla spp.) was assessed beyond harvesting them to sell or consume. In particular, using a questionnaire, the spiritual and cultural values of African freshwater eels and their associated freshwater environment in the uMngeni and uThukela catchments were investigated. A total of 154 people from different communities were interviewed along these river systems during 2021 and 2022. In the different communities within catchments, participants reported a number of different beliefs associated with eels and rivers. The responses showed that people valued clean rivers for various cultural, religious, and recreational activities. Some valued eels as they were associated with their beliefs. People who use freshwater for their respective cultural and spiritual, fishing, and domestic purposes voiced a considerable challenge in using freshwater systems, water pollution and water contamination from industrial waste or eutrophication from agricultural waste. Without community participation, there is no guaranteed sustainability of the water resources for the spiritual and cultural values of freshwater eels and freshwater systems. Community leaders and water management bodies must engage with communities in identifying important river uses (domestic, fisheries), and their contribution to spiritual and cultural practices. This will ensure long-term sustainable use and protection of inland water and fisheries resources associated with cultural and spiritual beliefs in KwaZulu-Natal. Freshwater eels hold a crucial aspect in the lives of traditional healers, some local fishers, and the general public, iii those that have knowledge of the use of these species. The study has shown that these species are still under-studied in KwaZulu-Natal, and most people have little understanding of the economic and cultural values, leading to less appreciation of these species by most people, mostly nonfishers.
Monitoring the efficacy of a lowland instream barrier on the lower uThukela River and the importance of river connectivity.
(2023) Van Zyl, Bradley Bruce.; Downs, Colleen Thelma.
Freshwater is the key to life on earth, with rivers being the pathway that allows it to run from mountains to the ocean, performing many important functions along its way. Humans rely on the many ecosystem services that freshwater provides, such as water quantity provision for domestic, industrial, and agricultural processes, food supply, water purification, and recreation and tourism, to name a few. Water-scarce countries, such as South Africa, are particularly vulnerable to water shortage issues and require many water supply solutions, like dams, weirs, and transfer schemes, to harvest the available rainfall. The uThukela River in KwaZulu-Natal is not only an important resource within its catchment but also to external catchments through inter-basin water transfer schemes, including that of the Thukela-Vaal transfer, which feeds the economically important hub of South Africa, the Gauteng Province. The lower uThukela River is a highly stressed system, with synergistic effects from multiple stressors relating to water quality, water quantity, habitat alterations, and wildlife disturbance affecting it. Additionally, the Lower Thukela Bulk Water Supply Scheme (LTBWSS) weir was recently constructed in its lower reaches, approximately 20 km upstream of the uThukela Mouth to the Indian Ocean, to provide bulk water to surrounding local municipalities. Due to the rich diversity of fish species in the region, particularly those with marine, estuarine, and freshwater migratory patterns, a fishway was incorporated into the design of the weir to facilitate fish movements over the weir. This study evaluated the impact that the LTBWSS weir has on fish community structures in the region and additionally assessed the efficacy of the fishway in allowing fish movements through it. Various sites were selected upstream, downstream, and on the tributary Mandeni ii Stream to assess environmental variables driving fish community structures, with passive and active sampling methods used to assess the fishway's functionality. Fish collection occurred at three sites upstream of the LTBWSS weir, four sites downstream of it on the uThukela River, and two sites on the Mandeni Stream. Abiotic variables relating to water quality, velocity, depth, and habitat were collected along with fish to determine which environmental variables were driving the fish communities at these sites. Multivariate analyses indicated that available substrate and cover, the average depth, and temperature were drivers of the fish communities in the study. Upstream sites showed lower species richness compared with downstream sites, with fish communities largely made of freshwater species and few euryhaline species. Additionally, individual species showed different responses to different environmental variables. Furthermore, since the construction of the LTBWSS, the loss of previously highly abundant cichlid species has occurred in the region. This is likely because of the synergistic effects of stressors created by it, such as the disruption of fine sediment transport, water abstraction, and pollution. Passive assessment of the fishway's efficacy in catering for migratory species used PIT telemetry. Budget constraints only allowed the installation of a single PIT antenna at the upstream entrance of the fishway, which was able to assess the upstream migration of fish from downstream. The results found that only eight individuals representing three species managed to navigate the fishway during the study successfully. This included Oreochromis mossambicus, Labeo molybdinus, and Clarias gariepinus. Active sampling involved electrofishing three key locations in the fishway on a monthly basis. Results showed that small-size classes of fish largely dominated the fishway and that the downstream entrance had the highest abundances and species richness. Further research on the role of the fishway in maintaining river connectivity is recommended. iii The outcomes of this study showed the importance that water resource managers have in maintaining the resource for humans and the environment. Knowing individual species' responses to environmental variables allows their populations to be better managed. Additionally, the outcomes of this study showed the importance of river connectivity past a barrier and highlighted the need for effective fish passage solutions in South Africa. It emphasised the need to better understand the migratory requirements of local fish to build better fish passage structures. Major stressors to be addressed include the impacts caused by barriers relating to flow releases, migration blocks, and habitat alteration upstream and downstream of them. Furthermore, the proper management of fish passage structures is essential to their functionality, which includes regular monitoring of the fishway for issues such as debris blockages and swiftly finding solutions to them to ensure that no undue delays or stress may occur for migratory fish.
Aardvark and people: can a shy species be widely known in a localised area?
(2022) Makwati, Nolutho.; Kraai, Manqhai.; Tsvuura, Zivanai.
The increase in human populations has led to humans sharing space with wild animals even in the natural habitats of the animals. Conflicts may arise when people and wildlife attempt to fulfill their needs which can be detrimental to one or both parties, and this type of conflict is called human-wildlife conflict (HWC). The human needs include people hunting wild animals for consumption of the animal and trading in animal body parts.Hunting is one of the factors that decreases populations of numerous animal species, and it occurs in many parts of the world e.g. in Africa, Asia and South America, where it contributes to extinction of species. The conservation and management of burrowing animals is a major challenge due to their elusive and nocturnal behaviour. The aardvark is an African medium-sized, burrowing mammal whose conservation status has not been updated recently due to the difficulties associated with studying nocturnal animals. Aardvarks may play a significant ecological role in the ecosystems in which they occur, such as by changing the landscape through their digging activities, or through affecting the dispersal of seeds. Therefore, the aim of this study was to explore the influence of humans on population trends and activity patterns of aardvarks outside protected areas, and to determine people’s perceptions about the animal. The study was conducted in Ncunjane village in Msinga Local Municipality, KwaZulu-Natal Province of South Africa. To understand people’s perceptions about aardvark in their community, I used a semistructured questionnaire survey. I asked personal information of the participants (sex, level of education and age), and questions related to people’s perceptions about the aardvark, such as people’s knowledge, myths, and their uses of the animal or its body parts. To determine activity patterns of the animal, I focused on aardvark foraging activities in a semi- arid savanna ecosystem that is also used as a communal rangeland over eight months between 2020 and 2021. I measured and quantified aardvark foraging holes using 53 50 m × 10 m transects where there was evidence of aardvark activity. In addition, I quantified aardvark burrowing of dens in the dry, wet and early dry seasons using walking transects guided by a research assistant who knows the area. I found that people have different perspectives about aardvark with the majority (78%) of respondents having strongly positive perceptions. The positive perceptions arise from aardvark not causing physical harm to people, and fleeing away upon sighting people. I found that aardvarks were mainly hunted for meat while some animal body parts were sold to traditional healers for traditional medicine. All seasons consisted of a greater number (> 51%) of old than new and very old foraging holes.The surface area of new, old, very old holes differed significantly with season (P < 0.0001) and the depth of new, old and very old holes also varied with season (P < 0.0001). In addition, the contents of foraging holes varied with age of the hole and season in that new holes lacked evidence of plant life across seasons. Aardvark dens were used by other animals such as spiders, wild cats, Cape porcupines and snakes. Hence, an increase in aardvark holes can be associated with significant landscape heterogeneity for vegetation and animal life. Aardvarks in Ncunjane fed close to their dens presumablyto mitigate against human predation through hunting threats, which may directly affect the extent of aardvark digging activities. These results show that aardvarks may be categorised as ecosystem engineers as the burrows provide shelter for other animals, also, their effects on other animals are disproportionate to their abundance. These results highlight that aardvarks are threatened by human uses and may decline in abundance in the area. Finally, aardvarks remain poorly studied in landscapes shared with humans. Further studies to assess aardvark numbers in human-dominated landscapes are required which can raise awareness and play a significant role in conservation of aardvarks.
The prevalence and implications of non-native wild boar Sus scrofa in KwaZulu-Natal, South Africa.
(2023) James, Claudette Njabulo.; Downs, Colleen Thelma.
Humans’ introduction of species into areas where they do not naturally occur has led to ecological and economic havoc. Introduced species can become invasive, exerting negative pressures on native species and the environment. Wild boar (Sus scrofa) is distributed worldwide except for Antarctica. The species is highly destructive and has been regarded as an invasive alien species in many parts of the world. Researchers have done many studies on wild boar investigating various aspects of the species, such as its biology, biochemistry, ecology, epidemiology, genetics, and archaeology. Invasive animals' effects on the environment and ecological systems were explored and focused on the impacts of exotic mammals, with wild boar as the species of interest. The potential for invasive spread by the European wild boar in South Africa was assessed by determining potentially suitable habitats using bioclimatic variables and the maximum entropy model, and then related to the present distribution records of the species in the country. Wild boars were found to have great potential to extend their invasive distribution range in South Africa. The prevalence of feral wild boar in KwaZulu-Natal (KZN) Province, South Africa, was investigated using camera trap surveys. The camera trap surveys revealed that there were no feral wild boar populations in the Midlands of KZN, but in other parts of KZN. The selling of wild boar in relation to the present legislation on wild boar in South Africa is illegal. The selling of wild boar contributes to the spread of the species in the country, as determined in this study. We recommend that the sale of wild boar should be monitored in South Africa by conservation authorities and the animals confiscated from the offenders and euthanised to prevent the further uncontrolled spread of the species. Moreover, we recommend the revision of the legislation regulating wild boar in South Africa to prevent the uncontrolled spread of the species in the country.
Assessing the trade of reptile species in the South African pet trade.
(2021) Mantintsilili, Asekho.; Downs, Colleen Thelma.; Shivambu, Tinyiko Cavin.; Shivambu, Ndivhuwo.
Despite the negative impacts that the pet trade has on the native and non-native biodiversity, economy and human health, the research suggests that the demand for pets and the extent of trade in live animals as pets has increased dramatically over the years. As a result, many species, including reptiles, have been translocated and introduced into new or non-native environments. Some of these have established feral populations, become invasive and are causing significant environmental and socio-economic impacts on non-native environments. Reptiles are among the most popular groups of animals in the pet trade industry globally. Trade in pet reptiles in South Africa is large and one of the major pathways through which non-native species, including invasive species, are introduced into the country. Despite this, little is known about the dynamics of the wildlife trade in pet reptiles globally. To understand the dynamics of the global trade in pet reptiles, we carried out a comprehensive literature search to gather relevant information from reptile pet trade-based publications. We further compiled a list of traded pet reptiles from all South African physical pet stores and online advertising websites to determine which species are traded, pose an invasion risk and have potential environmental and socio-economic impacts. We found a total of 39 publications based on the reptile pet trade from 1994 – 2021 worldwide. Our analyses revealed that the research effort was not uniform globally, with the majority (63.6%) of all relevant studies originating from three continents (Asia, Europe, and North America). Moreover, the United States of America (North America) and Indonesia (Asia) produced the greatest research outputs (12.1% each) compared with other countries across the world. We found at least 1140 reptile species belonging to 60 families involved in the global pet trade, with invasive red-eared slider Trachemys scripta elegans being the most frequently studied species (number of studies = 23/39). Of the recorded species, at least 79 are invasive, 46 endangered, 29 critically endangered, while only 546 are CITES-listed. In terms of reptile species sold in South Africa, we recorded a total of 2771 individuals representing 88 unique reptiles, 69 from physical pet stores and 18 from online advertising websites. KwaZulu-Natal, Gauteng and Western Cape Provinces had the highest number of pet stores and online advertising websites; therefore, they subsequently recorded the highest number of pet reptiles compared with other provinces. Physical pet stores were found to have the highest number of species compared to online trade. Of the recorded species, 76 are nonnative, and 15 of these are invasive to South Africa. Moreover, only 32 pet reptiles are listed under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). For current distributions, red-eared slider Trachemys scripta elegans, P. guttatus, and Western diamondback rattlesnake Crotalus atrox had the largest predicted climatic suitability. The future predictions for the latter two species were predicted to increase, while red-eared slider suitability shifted. Some species, such as Burmese pythons Python bivittatus, showed low invasion risk based on climatic suitability. However, given their large body size, history of invasion and their popularity in the pet trade, they are most likely to escape or be released from captivity and become invasive. A total of 76 reptile species were assessed for environmental and socio-economic impacts using the Generic Impact Scoring System (GISS), Environmental Impact Classification for Alien Taxa (EICAT), and Socio-Economic Impact Classification for Alien Taxa (SEICAT). Using GISS, we found that 13 species had environmental impacts (E_GISS), while 11 species had socio-economic impacts (SE_GISS). For EICAT and SEICAT, 13 species had environmental impacts, and eight had socio-economic impacts, respectively. The most popular pet species, red-tailed boa Boa constrictor, green iguana Iguana iguana, P. bivittatus, T. elegans, and central bearded dragon Pogona vitticeps had impacts in all the three scoring schemes. The later species and corn snake (Pantherophis guttatus) scored the highest for all impact schemes. Species sold in high numbers, with large climatically suitability and potential impacts, are more likely to establish feral populations and become invasive should they escape or be released from captivity. We, therefore, recommended that the trade in pet reptiles should be constantly monitored to avoid new introductions and the implications that the pet trade may have to the country.
Development and application of novel ornithological survey methods for the detection of cryptic avian indicator species that predict grassland health.
(2021) Beaumont, Stuart Nicholas.; Downs, Colleen Thelma.
The anthropogenic pressure on South African grasslands to meet the needs of the burgeoning human population has exposed them to extensive permanent transformation and degradation. Indicator species may identify changes in the grassland ecosystem. One such indicator species for natural sourveld grassland condition in South Africa is the red-winged francolin (Scleroptila levaillantii), whose population density is negatively correlated to grazing intensity and annual burning. Pointing dogs (Canis lupus familiaris) have been used extensively to aid ecologists in detecting these and other cryptic gamebirds to establish abundance. Here, a reliable method was developed to count cryptic gamebirds in the Greater uMgeni Vlei Expansion Area, KwaZulu-Natal Midlands, South Africa, where the route through a survey site was flexible. A variation to the existing distance sampling technique was proposed where the dog global positioning system (GPS) track was the transect line. The study investigated the effect of varying environmental conditions on the distance from which a pointing dog could reliably and consistently detect a bird and allow calculating a detection distance based on influential environmental variables. Between March – October 2021, using pointing dogs fitted with GPS devices, controlled and uncontrolled trials were conducted on Japanese quail (Coturnix japonica) and red-winged francolin in their natural habitat, respectively, to establish the environmental conditions that affect detectability and the detection distance from which a dog can detect a bird of known location. A total of 21 surveys were conducted (August 2020 – October 2021), on four survey sites by one or two pointer dogs fitted with GPS devices, to establish the population densities and territory of red-winged francolin. Individual area of search, established from the detection distance based on nominal wind speed and GPS track, was calculated. The redundancy in area of search enabled the evaluation of relative proficiency of detection of red-winged francolin. Of the environmental variables monitored, only nominal wind speed significantly influenced detection distance, where an increase of one-knot wind strength resulted in an increase in detection distance by 0.64 m. This enabled an area of search, considerate of influential environmental conditions, to be derived and the probability of detection within that search area = 1. Results showed significantly better precision and accuracy when surveying with two dogs when compared with one dog. The calculation of detection distance, where the probability of detecting a bird at this distance = 1, addresses the bias of varying scenting conditions. The established area of search, where the probability of detecting a bird within this area = 1, addresses the situation where known coveys in an area of known size remain undetected. Since the area of search is independent of time spent searching and normalised for redundancy, the bias introduced by varying physical aptitude is mitigated. Consideration for the application of this method should be given to the environmental conditions under which the surveying is planned since the detection distance function is derived for conditions at the present study sites. These techniques, based on a variable survey route through the survey site, may be used by citizen scientists to assist land managers, conservationists, and ecologists in establishing the abundance of red-winged francolin, contributing to burning and grazing regime management to enhance conservation efforts for the species.
Interactive effects of fire history and elevated 2 temperature on aboveground productivity in a high 3 altitude mesic grassland in South Africa.
(2021) Mvelase, Thembeka Ayanda.; Tedder, Michelle Jennifer.; te Beest, Mariska.
Abstract available in PDF.
Role and effects of wild southern African ungulates on seed dispersal of selected alien invasive plants.
(2021) Msweli, Lindelwa Sibongakonke.; Downs, Colleen Thelma.; Zungu, Manqoba Moses.
Abstract available in PDF.
Ant community responses to fertiliser application and disturbance in a mistbelt grassland, KwaZulu-Natal.
(2021) Khoza, Lindiwe Rebecca.; Munyai, Thinandavha Caswell.; Andersen, Alan N.
Abstract available in PDF.
The contribution of goats to household food security in selected communities of KwaZulu-Natal, South Africa.
(2021) Khowa, Anele Aurelia.; Kraai, Manqhai.; Tsvuura, Zivanai.
The growth of the human population in the world has been occurring at a rapid rate. This presents a challenge of how the world food demands will be met. These challenges are always felt the most in developing countries, and result in a lot of people in developing countries turning to alternative sources of income other than employment to manage their food situation. One of the alternatives includes a reliance on animal husbandry in order to meet and improve their livelihoods particularly with respect to food. Furthermore, small-scale farming of animals such as goats, sheep, pigs and chickens has also been an income source when the animals are sold. In developing countries, pastoralism and agro-pastoralism frequently occur among disadvantaged communities, who are often found in arid or semi-arid regions. As a result, goats have been shown to be an important type of livestock that can be kept in such conditions without financially stressing their owner by requiring constant care of supplementary feeds and medication. Goats are known for their resilience which allows them to cope with stressful conditions while being able to reproduce. This resilience and productivity of goats allows their owners to be able to liquidate them for cash if there is a need and also be able to slaughter them for their household consumption. Here, I investigated the contribution of small-scale goat farming to household food security in rural and peri-urban areas in KwaZulu-Natal (KZN), South Africa. The study was carried out in rural and peri-urban areas of Msinga, Kokstad, Howick and Pietermaritzburg in KZN. I used structured questionnaire surveys to determine the contribution of goats to household food security from the farmers’ responses. The questions asked related to the sale of goats (number, sex, age and sale value of the animal) and how the money generated from goat sales was spent. The study also determined goat sales from 27 households in three villages occurring in Msinga over a 2- year period of 2017 to 2018. I also assessed the participation of small-scale farmers in two livestock auctions, which took place in 2019 and 2020 by recording the age, sex, and coat-colour of the animals taken to auctions. The results obtained from the study showed that goats played a role in household food security as a source of cash as well as consumption in strenuous times. These findings of the study highlight that smallscale goat farming provides an alternative food source and income source for disadvantaged farmers. These findings were more prevalent in the rural areas, which kept more goats than those found in the peri-urban areas. Goats in rural areas ranged from 5 to 150 goats in a herd, and 5 to 50 goats in a herd while in periurban areas. Goats were a source of cash in numerous ways including sale of skins after slaughter that are used to craft household items such as stools that can be sold for cash. Adult goats were sold more at the farmers’ homesteads than auctions where buyers opted for younger goats. My results also showed that small-scale farmers use all possible avenues to sell their goats, as they sold a high number of animals from home and did not depend on infrequent livestock auction events. However, there were benefits derived from participating in auctions in terms of the relatively higher prices obtained there. For example, female and male goats sold for R2 177 and R1 268, respectively at auctions. The price was similar for females (R1 083) and males (R1 065) in homesteads. At auctions, female and male goats sold for R2 177 and R1 268, respectively. From homesteads, female and male goats sold for R1 083 and R1 065, respectively. Colour of goats proved to be an important trait at auctions as light-coloured goats were in higher demand than black goats. Homestead sales also remain a useful practice as farmers generate income to assist in day-to-day household expenses instead of waiting for infrequent auction events. Furthermore, small-scale farmers who plan to participate in auctions should pay attention to the characteristics (age, colour, and sex) of their animals when populating their herds. Sub-adult, light-coloured and female goats were the animals that were highly sought after at auctions.
Protected area management and planning challenges: sustainability and integrity – a cursory investigation of the role of the management plan.
(2021) Goosen, Magda.; Downs, Colleen Thelma.
Formally established protected areas in South Africa date back to the turn of the 19th century, yet requirements for protected area management plans only became mandatory approximately a century later. Before the promulgation of the Environment Conservation Act No. 73 of 1989 and subsequently the World Heritage Convention Act in 1999 and the National Environmental Management: Protected Areas Act 57 in 2003, requirements for management plans were voluntary, and guidance to its content was fragmented across various international, national and provincial policy instruments. There has been little academic debate on the relevance and content of protected area management plans to date and how such a long-term planning document can respond to emerging threats and opportunities. An improved understanding of these plans, and the role they play in biodiversity conservation, is required. The aims of this investigation were two-fold. The first was to gain insight into the challenges of effective management of protected areas, the long-term protection and sustainability of these areas, and, notably, the management plan’s role in addressing these challenges. The second was to evaluate the contribution and legislative weight that the management plan has in the efficient management, sustainable and ethical use, and long-term sustainability of protected areas within South Africa. Given that the above aims cover a potential insatiable field of research, this thesis was focused on the legal and policy framework for management plans and the management plans role in effectively managing these areas. Within this context, the following questions were addressed: ▪ What is the role of management plans in the effective management of protected areas? ▪ How does the legal and policy framework ensure that the derived plan is relevant and achievable and ultimately accomplishes the protected area purpose? ▪ What decision-making principles should be considered to facilitate sustainable and ethical use of protected areas, and what role does protected area management plans play in ensuring justifiable use of protected areas? ▪ What are the consequences when a long-term public-interest decision potentially isolates it from its transfrontier context, and what is the legislative weight of the management plan in mitigating such consequences? ▪ What role does the management plan, a long-term planning document, play in mitigating the impacts of or responding to immediate emerging threats and opportunities? It was found that despite being the principal legislative framework for management plans, the World Heritage Convention Act and the National Environmental Management: Protected Areas Act did not consolidate the plethora of management plan requirements for protected areas. As a consequence, the legislative provisions for protected area management plans were, in several instances, fragmented, conflicting and ambiguous. A consolidation of relevant provisions in these two statutes together with emerging best practice is, therefore, recommended. This consolidation may also provide greater clarity on the contemporary understanding of the contribution of protected areas to conservation and people’s well-being, i.e. it may entail a refurbishment of the ‘purpose’ of protected areas. Furthermore, the parallel evolution of the management of protected areas, the recreational use of these areas, and protected area management plans over the last century have brought about a complex relationship between these three aspects. Because of the fragmentation of legal and policy frameworks relating to these aspects, a need for a consolidated decision-making framework that provides for the basis for ethical and transparent decision-making could exclude inconsistent interpretations of legislation and policies. Incorporating such a decision-making framework in the protected area management plan can enhance transparency and accountability by the State or management authority to fulfil its fiduciary duty. Understanding of the above aspects was enhanced through a literature review and a case study of a development application in the area bordering the Tembe Elephant Park. The case study highlighted some of the potential consequences of a long-term public-interest decision that isolates a protected area from its transfrontier context and the role of an adaptive management plan in responding to these impacts and other current emerging threats and opportunities. A robust management plan remains the most relevant planning tool to address the complexities around protected area management and the fragmented legislative and policy frameworks for the effective management of protected areas in South Africa. Whereas management plans cannot be expected to cover explicitly every emerging circumstance – the principles included in such plans should provide the necessary guidance to decision-makers for unique circumstances and decision making.
Influences of bush encroachment and intensity on small mammals in a mesic savanna, Pretoria, South Africa.
(2021) Zwane, Thabile Jane.; Kraai, Manqhai.; Tsvuura, Zivanai.; Tjelele, Julius Tlou.
Abstract available in pdf.
Aspects of the urban ecology of the Spotted Thick-knee (Burhinus capensis)
(2021) Josiah, Kyrone Kent.; Downs, Colleen Thelma.
Abstract available in PDF.
Ecology of the South African giraffe (Giraffa camelopardalis giraffa) across a land-use gradient in central KwaZulu-Natal, South Africa.
(2020) Nyathi, Memeli Jefrey Jethro.; Downs, Colleen Thelma.; Calverley, Peter Markham.
Abstract available in pdf.
Parthenium hysterophorus distribution and efficacy of control in Hluhluwe-Imfolozi Park, northern KwaZulu-Natal.
(2020) Mbatha, Sethabile Khwezi.; Tedder, Michele Jennifer.; Carbutt, Clinton.; Mutanga, Onisimo.
Abstract available in pdf.

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