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Cooper, Tessa June Groves. "The effects of land use changes on the distribution of forest dependent bird species in South Africa." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/97842.
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Thesis (MSc)--Stellenbosch University, 2015.ENGLISH ABSTRACT: Forests in South Africa have had a long history of human utilization and disturbance, and are under threat from a variety of anthropogenic land use changes. Foremost of these are deforestation and forest degradation, impacting the species native to these forests. The aims of this study were to determine changes in the distribution of forest dependent bird species according to the South African Bird Atlas Project; to relate these changes to changes in land-use; to identify links between these changes; to determine the extent, location and causes of the decline of each forest dependent bird species; and to identify current risks to forest dependent bird species in South Africa. Range data on 57 forest dependent bird species from SABAP1 (1987-1992) and SABAP2 (2007-present) were analyzed. Of these, 28 species were found to have declining ranges. Thirty sites across South Africa were identified as being most at risk, with all having experienced a loss of more than 10 of the 57 forest dependent bird species between SABAP1 and SABAP2. The range change data of the 28 species with decreasing ranges were correlated with data on changes in land cover over the same time period to infer relationships between changes in land use and change in bird ranges. Occupancy modelling was done to determine which land cover types affect extinction and initial presence. Individual species characteristics were analyzed to determine links between characteristics and response to land use change. A pan-European trait-based risk assessment framework was applied to all 57 species to identify habitats and species most at risk, as well as the most important threats to species persistence. Results showed that natural vegetation decreased in 67% of sites, while plantations and cultivation increased in 50% of sites. Occupancy modelling showed extinction likelihood to increase with plantations in some species, while plantations mitigated extinction likelihood in other species. Urbanization and cultivation likewise mitigated extinction likelihood in some species. Natural vegetation was replaced by cultivation, while cultivation was replaced by urbanization. The number of species lost increased with a loss of natural vegetation. Twenty two of the thirty sites experienced deforestation of indigenous forests between 2000 and 2013/2014; changes in natural vegetation in these sites can be attributed primarily to deforestation, and a loss of plantations. While most at-risk sites were in the Eastern Cape, there was no geographic grouping of species loss or of land use change. Most species lost were birds of prey or insectivores, and species characteristics and habitat preferences determined the sites from which they were lost. The Cape parrot (Poicephalus robustus), rufous-chested sparrowhawk (Accipiter rufiventris) and the migratory Eurasian golden oriole (Oriolus oriolus) suffered the largest declines in range size and are thought to be most at risk. Montane forests were found to be more at risk than other forest types. The major risks facing montane forests were increased abundance of small predators, increased fire suppression, increased soil management, removal of deadwood and reduced diversity of tree species. These threats are all products of plantation forestry and local harvesting. Nesting risk was higher than foraging risk for all species, indicating that nesting habitat should be better preserved. Half of South Africa’s forest dependent bird species have declining ranges, with the loss of these species most prominent in the Eastern Cape. Natural vegetation loss, comprising mostly recent deforestation; increased cultivation and urbanization; and changes in plantation cover are thought to be the main factors determining these declines. Montane forests in particular should be better protected to preserve forest dependent species, and the negative effects of plantation forestry and local harvesting should be mitigated.
AFRIKAANSE OPSOMMING: Suid-Afrika het ‘n lang geskiedenis van woude wat deur mense gebruik, asook vernietig word. Woude word bedreig deur verskeie menslike grondgebruike en veranderinge. Die mees vooraanstaande van die bedreigings is ontbossing en woud verdunning, wat ‘n invloed het op inheemse spesies in die woude. Die doelwitte van hierdie studie was om veranderinge in die verspreiding van bos-afhanklike voëlspesies vas te stel volgens die Suid Afrikaanse Voël Atlas Projek; om hierdie veranderinge te verband met veranderinge in grondgebruik; om verbande tussen hierdie veranderinge te identifiseer; om die mate, die plek en die oorsake van die agteruitgang van elke bos-afhanklike voëlspesies te bepaal; en om huidige risiko's aan die bos afhanklik voëlspesies in Suid-Afrika te identifiseer. Trefwydte inligting oor 57 woud afhanklike voëlspesies van SABAP1 (1987-1992) en SABAP2 (2007-nou) was geanaliseer. Daar was gevind dat vanuit die spesies, het 28 ‘n afneming in trefwydte ervaar. Dertig terreine in Suid-Afrika was uitgeken as dié met die hoogste risiko, met ‘n verlies van meer as 10 van die 57 woud afhanklike voëlspesies tussen SABAP1 en SABAP2. Die trefwydte inligting van die 28 spesies met ‘n afnemende trefwydte was gekorreleer met inligting oor veranderinge in grond bedekking oor dieselfde tydperk om verhoudings tussen veranderinge in grond gebruik en veranderinge in voël trefwydtes aftelei. Besetting modellering was gedoen om te bepaal watter tipes grond bedekking beinvloed uitwissing en aanvanklike teenwoordigheid. Kenmerke van individuele spesies is ontleed om verbande tussen kenmerke en reaksie op verandering in grondgebruik te bepaal. ‘n Pan-Europese eienskap gebaseerde risiko-analise raamwerk is toegepas op die 57 spesies om die spesies en habitatte met die grootse risiko te identifiseer, asook die belangrikste bedreigings vir spesies-volharding. Die resultate het gewys dat natuurlike plantegroei het verminder in 67% van terreine, terwyl plantasie en verbouing vermeerder het in 50% van terreine. Besetting-modellering het gewys dat waarskynlikheid van uitwissing vermeerder met plantasies in sommige spesies, terwyl plantasies die waarskynlikheid van uitwissing verminder het in ander spesies. Verstedeliking en verbouing het ook die waarskynlikheid van uitwissing verminder in sommige spesies. Natuurlike plantegroei was vervang deur verbouing, terwyl verbouing vervang is deur verstedeliking. Die aantal spesies verlies het vermeerder met die vermindering van natuurlike plantegroei. Twee en twintig van die dertig terreine het ontbossing van inheemse woude ervaar tussen 2000 en 2013/2014. Veranderinge in natuurlike plantegroei in die terreine is meestal as gevolg van ontbossing, en ‘n vermindering van plantasies. Terwyl meeste van die hoë risiko terreine in die Oos-Kaap was, was daar geen geografiese groepering van spesies vermindering of grondgebruik veranderinge nie. Meeste spesies wat vernietig is was roofvoëls of insectivore, en spesies kenmerke en habitat voorkeure het die terreine bepaal waaruit hulle verloor is. Die grootpapegaai (Poicephalus robustus), rooiborssperwer (Accipiter rufiventris) en die trekvoël Europese wielewaal (Oriolus oriolus) het die grootste vermindering in trefwydte grootte ervaar, en is vermoedelik die grootste risiko. Bergwoude was gevind om meer in gevaar te wees as ander woud tipes. Die grootste risikos wat bergwoude beïnvloed het was ‘n toenemende hoeveelheid klein roofdiere, verhoogde vuur onderdrukking, verhoogde grondbestuur, verwydering van dooie hout, en verlaagde diversiteit van boomspesies. Hierdie bedreigings is almal as gevolg van plantasie bosbou en plaaslike oes. Nes-risiko was hoër as kos soek risiko vir alle spesies, wat aandui dat nes-habitat beter bewaar moet word. Die helfte van Suid-Afrika se woud-afhanklike-voëlspesies het dalende trefwydtes, met die verlies van hierdie spesies mees opvallend in die Oos-Kaap. Die verlies van natuurlike plantegroei, as gevolg van onlangse ontbossing; verhoogde verbouing en verstedeliking; en veranderinge in plantasie bedekking is vermoedelik die hooffaktore wat die vermindering van voëlspesies veroorsaak. Veral bergwoude moet beter beskerm word om woud-afhanklike-voëlspesies te bewaar en die negatiewe invloede van plantasiebosbou en plaaslike oes te verminder.
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Wyma, Rindert. "Birds of the riparian corridors of Potchefstroom, South Africa / Rindert Wyma." Thesis, North-West University, 2012. http://hdl.handle.net/10394/9545.
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A riparian ecosystem is the area between the aquatic and terrestrial setting of a stream, and serves as a corridor and habitat for birds. Several riparian ecosystems are located in urban environments, and three main riparian corridors are located in Potchefstroom. They are the Mooi River, Wasgoed Spruit, and Spitskop Spruit, which encompass a wide range of different vegetation types and anthropogenic factors. Therefore, different habitat types for birds occur along the riparian corridors of Potchefstroom. Factors such as food and water availability, nesting sites, competition, predation, learning, presence of other species, and those species that are able to adapt to environmental changes influence the avian diversity and communities along riparian corridors.
The hypothesis is that bird variables along the riparian corridors in Potchefstroom are affected by vegetation, anthropogenic, and seasonal influences. To investigate these affects, two secondary objectives were formulated. The first was to characterise riparian avian habitats (CAHs) according to vegetation and anthropogenic factors, and the second was to identify temporal and spatial changes in avian variables.
The three streams were divided into 79 consecutive transects, each 300 m long. The study area consisted of: 17 transects along Spitskop Spruit, 12 along Wasgoed Spruit and 50 along the Mooi River. Bird observations were conducted monthly from June 2006 to June 2007. Birds that were observed with a perpendicular distance ≤ 30 meters towards the streams were included in the results. The bird species that were observed were also classified into different nesting and feeding guilds.
Environmental data recorded included: vegetation structure (estimated cover percentages and height classes of trees, shrubs, grasses, herbs, sedges, and reeds), anthropogenic structures (estimated cover percentages of roads, footpaths, bridges, electrical pylons, houses, and drainage pipes), and the presence of informal settlers along each transect (the mean number of people and the space they occupy). Vegetation was monitored in summer– (February 2007 until April 2007) and winter months (June 2007 until August 2007). The anthropogenic structures and the presence of informal settlers (anthropogenic factors) were monitored simultaneously with the bird counts.
Transect-time profiles were drawn for the four parameters, which differed on spatial and time scales. Multivariate analyses included non-metric multidimensional scaling (NMS), cluster analysis, and indicator species analysis. Cluster analyses and NMS bi-plots were used to define characterised avian habitats (CAHs). Two types of CAHs were characterised: Summer CAHs (summer vegetation and anthropogenic factors) and Anthropogenically CAHs (Anthropogenic factors alone). Bird species were then ordinated with the summer and anthropogenically CAHs on NMS successional vector graphs. The successional vectors illustrate the avian community trajectories of the different CAHs. Indicator species analyses were performed to describe associations between the bird species and the summer and anthropogenically CAHs.
The summer and anthropogenic CAHs that were characterised had different avian community trajectories and different species were associated with these CAHs. Different levels in avian diversity appeared among these CAHs, and convergence and divergence in communities appeared among these CAHs. Birds also selected their habitats according to feeding and nesting behaviours.
Consequently, it can be deduced that environmental factors such as vegetation structures and anthropogenic factors, as well as seasonality, had an effect on the distribution of birds along the riparian corridors of Potchefstroom.Thesis (Master of Environmental Sciences)--North-West University, Potchefstroom Campus, 2013
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Earlé, Roy Anthony. "The biology of the South African cliff swallow hirundo spilodera." Thesis, Rhodes University, 1986. http://hdl.handle.net/10962/d1004927.
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The general biology of the South African Cliff Swallow Hirundo spilodera was studied over a two year period in the central Orange Free State. This species is highly colonial, nesting mostly on man-made structures such as concrete road bridges. Adult birds were usually faithful to their breeding colony and very few individuals changed colonies. The Cliff Swallow had a surprisingly large vocal repertoire for a swallow and contact calls of the young were individually recognizable. Three species-specific ectoparasites parasitized the Cliff Swallow but none seemed to have a noticeable negative effect on the swallows. Breeding started earlier in larger colonies than in smaller ones and conspecific brood parasitism was a common feature in some colonies. Individual pairs made up to four breeding attempts per season. The findings of this study are compared with the available information on other members of the Hirundinidae and the advantages and costs of Cliff Swallow coloniality are discussed.
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Visser, Elke. "The impact of South Africa's largest photovoltaic solar energy facility on birds in the Northern Cape, South Africa." Master's thesis, University of Cape Town, 2016. http://hdl.handle.net/11427/20843.
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Renewable energy is a promising alternative to alleviating fossil fuel-based dependencies, but its development can require a complex set of environmental trade-offs for bird communities in the area, ranging from effective and physical habitat loss to direct collision-related mortality. The wide variation in the nature and significance of predicted impacts of utility-scale photovoltaic (PV) facilities on birds, and the low levels of confidence attending these predictions, has emphasised the need for scientific research. This study assesses the risks to bird populations and guilds at one of South Africa's largest PV developments. Firstly, in order to identify functional and structural changes in bird communities in and around the development footprint, bird transect data were gathered, representing the solar development, boundary, and untransformed landscape. Secondly, to assess the risk of collision mortality with solar-related infrastructure, representative samples (core vs. edge) were surveyed for bird carcasses and other signs of collision for three months covering 20-30% of the facility at search intervals of 4, 7 and 14 days. In order to account for potential biases in carcass detection, searcher efficiency and carcass persistence trials were conducted. The distribution of birds in the landscape changed, from a shrubland to open country and grassland bird community, in response to changes in the distribution and abundance of habitat resources such as food, water and nesting sites. These changes in resource availability patterns were detrimental to some bird species and beneficial to others. Shrubland specialists, such as the black-chested prinia (Prinia flavicans) and chestnut-vented tit-babbler (Parisoma subcaeruleum), appeared to be negatively affected by the presence of the PV facility. In contrast, open country/grassland and generalist species, especially species such as the Cape sparrow (Passer melanurus) and familiar chat (Cercomela familiaris), were favoured by its development. Utility-scale PV facilities inevitably will not substitute for the natural habitats they have replaced, but might offer opportunities for climate protection that do not necessarily conflict with nature conservation. Monitoring success of avian mortality was significantly influenced by variation in detection rates by size class (60 and 95% for birds <100 g and >100 g, respectively) and the location of carcasses relative to the solar panel units (65 and 90% for birds adjacent and under the units, respectively) as well as decreasing persistence rates per search interval (57, 53, and 40% after 4, 7, and 14 days, respectively). Only injuries associated with non-fatal collision of large-bodied birds with the underside of the panels and entrapment between fencing could be concluded with reasonable certainty. An extrapolated fatality estimate of 4.53 fatalities.MW⁻¹.yr⁻¹ (95% CI 1.51-8.50), short study period, and lack of comparable results from other sources made it difficult to provide a meaningful assessment on avian mortality at PV facilities. Despite these limitations, the few bird fatalities that were recorded might suggest that there is no significant link with collision-related mortality at the study site. In order to fully understand the risk of solar energy development on birds, further collation and analysis of data from solar energy facilities across spatial and temporal scales, based on scientifically rigorous research designs, is required.
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Stephenson, Alan. "Ecology and breeding biology of Lanner Falcons in the Eastern Cape Province, South Africa." Thesis, Rhodes University, 2001. http://hdl.handle.net/10962/d1005352.
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Lanner Falcons Falco biarmicus are the commonest large falcons in Africa and this study in the coastal area of the Eastern Cape Province, South Africa investigated their ecology from 1984 to 2000. Lanners have recently been categorised as near-threatened and this study was initiated to ascertain if the population was stable. Breeding success of a small population, in different habitat types, was monitored intensively from 1997 to 2000, and the factors that inhibited breeding were investigated. The earliest onset of incubation was 17 July and the latest 16 August, with 2.2 young fledged per breeding pair over the four-year period. Incubation lasted 32 days and young fledged after 42-45 days. All nest sites were on cliffs with a mean height of 114 m, a mean vertical face of 53 m; 45% of the nests were in ravens’ nests. The aspect of cliff sites also influenced breeding success. Radio tracking was used to determine home range, habitat use and hunting methods, with prey species identified. Home ranges were between 66 km² and 249 km². Preferred prey was domestic chickens, pigeons and small birds during the breeding season. Foraging ranges were smaller in intensively cultivated areas with seed crops. Data obtained from ringing returns showed that no long distance movements occurred in this region, but two juveniles dispersed 152 km and 127 km. Conservation aspects with possible threats to Lanner Falcons such as poisons, electrocutions and direct persecution are discussed with some recommendations made for future research. Evidence from this study indicates that Lanner breeding success is not limited by nest site availability, but by rainfall timing and prey availability. Lanners foraged more in open areas than areas with tall vegetation, and benefited from intensive agriculture. This population appeared to be healthy and in no danger of declining in the near future.
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Botha, Jonathan Aubrey. "Resource partitioning in the world’s largest gannetry." Thesis, Nelson Mandela Metropolitan University, 2017. http://hdl.handle.net/10948/14707.
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Understanding strategies of resource partitioning within populations is a fundamental aspect of the study of ecology, and one which has been well documented across various taxa. In seabirds, sex-specific differences in foraging behaviour are often thought to reflect strategies of resource partitioning to avoid intra-specific competition. At present Bird Island in Algoa Bay hosts the world’s largest breeding population of gannets, with recent population estimates numbering well over 90 000 breeding pairs. Given the large size of this colony, intense levels of intra-specific competition are expected during the breeding season, particularly in years of poor feeding conditions. In addition, continuous foraging around the breeding colony may lead to the local depletion of prey as the season progresses, calling for flexibility in the foraging behaviour and diet of breeding individuals. Therefore, the aim of this dissertation was to investigate resource partitioning in Cape gannets breeding at Bird Island through strategies of sex-specific foraging and intra-seasonal variability in foraging behaviour and diet. To achieve this, the spatial and temporal aspects of Cape gannet foraging behaviour were assessed during the early stages of chick rearing, over two consecutive breeding seasons (2011/12, 2012/13) using GPS tracking and VHF monitoring. In addition, intra-seasonal variability in foraging behaviour and diet were investigated, taking into account the influence of sex and chick age, to provide a comprehensive assessment of foraging behaviour throughout the chick rearing period. GPS tracking data for 79 birds revealed limited evidence for sex-specific differences over spatial dimensions. An extension in the foraging range of females during a year of lower prey availability (2012/13) was, however, evident. This suggests a possible sex-specific response to prey limitation, likely reflecting resource partitioning strategies or differences in nutritional requirements. VHF data for 95 additional birds revealed a clear pattern in temporal foraging behaviour. In general, females were more likely to be on a foraging trip during the early and mid-day hours, with the probability of males being on a foraging trip increasing towards the late afternoon. Continuous tracking of individuals throughout the 2015/16 breeding season further revealed little evidence for sex-specific differences in spatial distribution and forging effort during both the guard and post-guard stages of chick rearing. A clear increase in foraging range was evident during the early stages of chick rearing as the season progressed. However, birds attending chicks older than 50 days showed an unexpected contraction in foraging range, which appeared to coincide with a dietary shift. During the early stages of breeding the diet was comprised almost exclusively of anchovy, the proportion of which decreased progressively in the diet throughout the breeding season. This was mirrored by a substantial increase in the proportion of saury in the diet. These results suggest that Cape gannets increase their foraging range in response to local prey depletion as the breeding season progresses. However, when alternative prey becomes available they may shift their diet, allowing them to access prey closer to the breeding colony. Overall, this dissertation provides insight into sex-specific behaviour in a monomorphic seabird, suggesting a marginal degree of spatial segregation. The results provide the first support for sex-related temporal foraging segregation in gannets. Such separation could potentially be driven by resource partitioning, but could also relate to differential nutritional requirements. In addition, this study also provided the first comprehensive assessment of foraging behaviour throughout the guard and post guard stages of chick rearing in gannets. These results suggest that a combination of foraging and dietary flexibility may allow Cape gannets to buffer the effects of prey depletion during the breeding season. In conclusion, resource partitioning through sex-specific foraging appears to be limited in the Cape gannet population at Bird Island. Segregation via alternative pathways may however be possible and as such, future studies should consider the influence of individual level segregation and habitat specialization.
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Kerseboom, Simone. "Pitied plumage and dying birds : the public mourning of national heroines and post-apartheid foundational mythology construction." Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1019884.
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The original contribution of this thesis is the examination of the official construction of a post-apartheid foundation myth through the analysis of the dead body politics of five iconic South African women that spans the three presidencies that have defined South Africa’s democratic era. This thesis examines the death and funeral of Albertina Sisulu, the return and burial of Sara Baartman, and the commemoration of Charlotte Maxeke, Lilian Ngoyi, and Helen Joseph. Sisulu, Baartman, Maxeke, Ngoyi, and Joseph have been constructed as heroines and as foundational figures for the post-apartheid nation in official rhetoric. It will contend that the dead body politics of these women not only informs a new foundational mythology, but also features in the processes of regime legitimation when the ANC-dominated government faces strong societal criticism. Although such official expressions of nationalism may appear exhausted, this thesis will show that nationalism remains a powerful and dangerous force in South Africa that attempts to silence opposition and critical analysis of perceived failing government policies or inaction. This thesis will indicate that as women’s bodies and legacies are appropriated for nationalist projects they are subsumed in discourses of domestic femininity in official rhetoric that dangerously detract from women’s democratic rights and their ability to exercise responsible and productive citizenship in the post-apartheid state. It will argue that women’s historic political activism is contained within the meta-narrative of ‘The Struggle’ and that women are re-subsumed into the patriarchal discourses of the past that are inherited in the present. This thesis approaches this topic by considering a top-to-bottom construction of post-apartheid nationalism through applying feminist critical discourse analysis to official rhetoric articulated at the public mourning and commemorative rituals of these five women.
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Oswald, Krista Natasha. "Seasonal physiological responses in the Cape Rockjumper (Chaetops frenatus): a Fynbos endemic bird shows limited capacity to deal with temperature extremes." Thesis, Nelson Mandela Metropolitan University, 2016. http://hdl.handle.net/10948/12994.
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The Fynbos biome in south-western South Africa is a global biodiversity hotspot vulnerable to climate change. Of the six Fynbos-endemic passerines, Cape Rockjumpers (hereafter Rockjumpers; Chaetops frenatus) are most vulnerable to increases in temperature, with population declines correlated with warming, and low physiological heat thresholds. Rockjumper’s preferred mountain habitat is predicted to decrease as they lack opportunity to move to cooler regions as temperatures warm. As Rockjumpers currently occupy the coldest regions of the Fynbos, I hypothesized their thermal physiology would show cold adaptation at the expense of lowered ability to cope with higher temperatures. I aimed to determine the seasonal 1) maintenance metabolism and cold tolerance, and 2) thermoregulatory responses to high temperatures of Rockjumpers. I measured seasonal maintenance metabolic rate, thermal conductance, and maximum thermogenic capacity. I also measured seasonal resting metabolic rate, evaporative water loss, evaporative cooling efficiency, and body temperature at high air temperatures. In winter, Rockjumpers had higher maximum thermogenic capacity, lower maintenance metabolic rate, and lower thermal conductance. Lower maintenance metabolic rates (and thus, lower metabolic heat production) combined with the decreased thermal conductance, confers substantial energy savings in winter. The increased winter maximum thermogenic capacity of Rockjumpers was expected, although the mean seasonal values fell below those expected for a ~ 50 g bird using a global data set, suggesting Rockjumpers are not especially cold tolerant. I further show that in summer Rockjumpers had higher elevations in resting metabolic rates, evaporative water loss, and body temperature, denoting higher rates of heat production and lower heat thresholds in summer compared to winter. My results suggest that Rockjumpers are best suited for relatively mild Krista Oswald Dissertation Chapter 1: General Introduction temperatures. While I found further support for a physiological basis for declining Rockjumper populations, further studies on other mechanisms Rockjumpers may possess to cope with climate warming (e.g. behavioural adjustments) are needed in order to truly understand their vulnerability to climate change.
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Taylor, Martin Russell. "An evaluation of bird presence and breeding activity in regenerating coastal dune forests, Maputaland, South Africa." Diss., Pretoria : [s.n.], 2007. http://upetd.up.ac.za/thesis/available/etd-04172008-093938.
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Van, Niekerk Mark Harry. "Quantifying crop damage by Grey crowned crane balearica regulorum regulorum and evaluating changes in crane distribution in the North Eastern Cape, South Africa." Thesis, Rhodes University, 2011. http://hdl.handle.net/10962/d1005436.
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Complaints of crop damage by cranes on planted maize in the North Eastern Cape, South Africa, have been increasing since the mid-1990‘s, and in some instances severe losses have been reported. Crop damage by the Grey Crowned Crane Balearica regulorum regulorum near the town of Maclear (31º04´S 28º22´E), has been quantified over two growing seasons, and assessed relative to losses caused by foraging Cape Crows Corvus capensis and other feeding damage assumed to be caused by insects. Twelve fields were selected based on previous patterns of crop depredation. Maize seed in seven of the fields was treated with the chemical ‗Gaucho‘ and five fields were planted with untreated maize. In order to determine the source of losses, twenty quadrats (4 m x 4 m) randomly distributed within each field were visited on average every second day, for a period of up to twenty eight days. Results indicate that seed treatments do act as a deterrent to feeding by both cranes and crows, however crane damage is generally insignificant compared to other sources of damage. My study also reviewed past sightings data of the Grey Crowned Crane in an effort to determine if the conversion of former grassland to plantations in this region may have increased foraging activity in maize fields. The data did not allow for clear-cut conclusions regarding changes in distribution or population trends. Conclusions provide direct input into the management of agricultural areas by enabling landowners to take steps to mitigate crop damage. These mitigation measures may either involve the application of seed treatments, or the planting of low risk crops in high risk areas. Future studies should consider the ppossible detrimental effects of chemical seed treatments on crane biology.
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Green, David Bruce. "Foraging ecology of Cape Gannets (Morus Capensis) at Bird Island, Algoa Bay." Thesis, Nelson Mandela Metropolitan University, 2013. http://hdl.handle.net/10948/d1020790.
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The Cape gannet has undergone considerable population change and redistribution over the past 50 years. This has been linked to shifts in the abundance and distribution of their dominant prey, sardine and anchovy. Five breeding colonies, along the west coast of Southern Africa, have shown rapid population declines as a result of reduced prey availability. In contrast, a single colony (Bird Island, Algoa Bay) on the south coast of South Africa has, over the same period, grown fivefold and now supports approximately two thirds of the total population. Due to its conservation importance, and isolation from other breeding localities, it is important to assess the health of the Bird Island colony, and determine how foraging distribution relates to the environment to evaluate current measures of protection. This was achieved through two related studies; a long-term dietary analysis spanning 34 years, and a spatial foraging study, which related three years of tracking data to estimates of prey availability, oceanographic features and marine protected areas (MPAs). The results of the dietary study showed that the dietary constituents of Cape gannets breeding at Bird Island have remained similar over the last three decades, but the importance of sardine and anchovy has increased significantly. For sardine, in particular, this reflects an increased availability of this species (as deduced from hydroacoustic surveys) within the foraging range of the Bird Island colony. The dietary abundance of anchovy was found to be negatively correlated with that of sardine. Surprisingly,.the dietary abundance of anchovy was also negatively correlated with estimates of its availability based on acoustic surveys. The latter is likely to be due to sardine being a preferred prey item. Recent decreases in the dietary contribution of sardine (since 2005) suggest that this species is becoming less available to gannets, with profound implications in terms of nutrient gain associated with foraging. However, this has been mediated by an increase in the dietary contribution of anchovy, which now accounts for the vast majority of prey taken. Spatially, the foraging range of the Bird Island colony expanded during the three years of study, indicating an increase in effort. This increase was likely in an effort to track a distributional change of sardine and anchovy, which showed an apparent westward shift during the study period. There was, however, no evidence of birds tracking features associated with high productivity. This may have been partly due to anomalously warm conditions during the summer of 2012/2013, in which an absence of coastal upwelling prevented surface cooling. Nonetheless, low sea surface temperatures and high chlorophyll a concentrations do not seem to be reliable indicators of important Cape gannet foragingareas. Foraging effort was largely concentrated outside of MPAs, indicating that the current MPA network provides little protection for foraging gannets. This could change with the additional protection of the proposed Greater Addo Elephant National Park MPA expansion, as prey species are allowed to recover following the removal of fishing pressure. Overall, the colony appears to be in good condition as the diet is still dominated by live prey items, and the foraging range remains smaller than many of the colonies along the west coast. However, it is important that monitoring be continued, in particular with respect to changes in the availability of sardine and anchovy. Long-term shifts of these species out of the colony‘s foraging range could negatively influence the population in the future. This might be worsened by interspecific competition for prey resources. Considering the conservation importance of this population, maintenance of healthy prey stocks within the home range of breeding Cape gannets should be prioritised in order to prevent declines similar to those observed at west coast colonies.
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Rishworth, Gavin Midgley. "Time-activity budgets of cape gannets (Morus Capensis) at Bird Island, Algoa Bay." Thesis, Nelson Mandela Metropolitan University, 2014. http://hdl.handle.net/10948/d1021046.
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For several decades now, seabirds have been considered to be useful indicators of the state of their prey resources because of how they reflect lower-level trophic variability through proxies such as diet or behaviour. However, collection of appropriate data is often challenging in the marine environment because of logistical or financial constraints. In this study, time-activity budgets were studied in the Cape gannet (Morus capensis), a seabird which has been advocated as a potential bioindicator for local epipelagic prey. VHF transmitters attached to PVC leg-rings were fitted to 50 adult breeding pairs during the 2011/2012 and 2012/2013 breeding seasons at Bird Island, Algoa Bay, to determine whether an automated method of continuously collecting time-activity budget data can replace conventional laborious direct observations. To validate that the foraging trip duration data generated from the automated method was a reflection of foraging effort, Time-Depth Recorders (TDRs) were simultaneously equipped to birds with VHF transmitters for three weeks. In order to assess the influence of factors other than prey availability on parent time-activity budgets, sex, chick age and body condition were measured. Additionally, chick growth and survival were recorded in order to investigate the gender-specific effects of parental time-activity budget variability on these parameters. Attachment of VHF transmitters to leg-rings of adult Cape gannets had no observable negative effects on the adults or their chicks in terms of adult body condition, nest attendance and foraging trip durations, or chick growth and survival. Furthermore, the frequency distribution of behaviour bout (foraging trip and nest attendance) durations was no different between automated and directly observed data. However, the automated method did record shorter behaviour bouts, largely attributed to the increased likelihood of direct observations missing birds returning briefly to their nests during older chick provisioning. Additionally, foraging trip duration was highly correlated to foraging effort in terms of time spent resting on the sea surface, flying and diving. The automated method therefore appears to be a good reflection of direct nest attendance observations and foraging effort. Cape gannet time-activity budgets were related to chick age and parental sex. Especially as chicks neared fledging, females spent significantly longer periods of time foraging than males, with males consequently provisioning their chicks more often. Furthermore, adults departing their nests earlier spent more time away from the nest foraging as more same-day daylight hours were available. Chick growth was a function of parent foraging trip duration and associated prey delivery rates. Chick survival was most strongly affected by the amount of time which chicks were left unattended by both parents and consequently exposed to predation by kelp gulls (Larus dominicanus) or to adverse weather conditions. Additionally, for females (but not males) there appeared to be a trade-off between foraging trip duration and chick survival. The Cape gannet appears to demonstrate a strategy whereby the costs of reproduction to the female are shifted towards male-dominated chick provisioning as the chick nears fledging. Drivers of time-activity budget variability such as chick age and parental sex therefore need to be considered if using data on foraging trip duration as a proxy of foraging effort and prey availability.
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Whittington-Jones, Craig Alun. "The ecology of the red-billed quelea Quelea Quelea (Linnaeus) and other granivorous birds at Eastern Cape feedlots." Thesis, Rhodes University, 2002. http://hdl.handle.net/10962/d1003286.
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Red-billed Quelea Quelea quelea have expanded their range in the Eastern Cape and now occur throughout the year in new areas. Recent changes in agricultural practice have probably been a contributing factor as flocks are larger than previously recorded and were more often associated with artificial food sources than natural grasses. Ringing and census data indicate that quelea have reduced movements during the non-breeding season and may display strong fidelity (over successive years) to dry season quarters with reliable food supplies. Although the recapture/recovery rate for quelea in the Eastern Cape (1.0-2.5%) was higher than the national average, it was still lower than expected and there may be considerable movement between nearby feeding sites. Some quelea breed locally, but most disperse during summer and their numbers at the feedlots were generally highest in winter and spring. The breeding season of quelea is later than other ploceids in the region and post-nuptial moult overlaps with winter. Replacement of primary wing feathers is relatively slow (124 days), and this is considered an adaptation to minimise disruption of flight capabilities and insulation. Significantly more quelea in the Eastern Cape have breeding plumage suffused with pink than in other southern African populations. However, during the non-breeding season there is apparently considerable intermixing between local populations and those from further north and the existence of a local sub-species is not supported. Seeds of two grass species, Echinochloa sp. and Urochloa panicoides, and two weed species, Amaranthus sp. and Chenopodium sp., were important in the diet of both quelea and Laughing Doves Streptopelia senegalensis. Maize comprised a large proportion of the diet of these species and losses at one ostrich feedlot were estimated at over R 17 000 in two years. Dependence on artificial food sources was generally greatest in winter and spring, but economically significant damage was not confined to this period. Alpha-chloralose showed good potential for reducing numbers of problem birds at livestock feedlots. However, the dynamic nature of problem bird populations favours a non-lethal management approach. Reduction of feed loss through manipulation of the ostrich ration could provide a relatively cheap and effective alternative to lethal control if applied appropriately.
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Wala, Zingfa Jantur. "Birds and people: studies based on citizen science and census data of Greater Gauteng, South Africa." Doctoral thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/29541.
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Global human population growth has been predicted to grow exponentially, to a point where it exceeds the capacity of available resources to sustain it. The consequences that such exponential increase will have on the environment has also been the focus of several research. The spatial pattern of human population has reveal uneven pattern of human population with the urban areas being subject of increased influx of human population from the rural areas in search of better economic factors. The United Nations in 2007 revealed that at least half of the world’s 6.6 billion human population was living in urban areas. This number is expected to increase to over 60% of the world's population by the end of 2050. Most of this population growth is occurring in developing countries. While the health, security and town planning amongst other consequences of this global explosion in urbanization have been well-studied and documented, the impact which urbanization is having and will have on the ecosystem and on biodiversity, especially at regional and local scales has remained an a field of knowledge that has continued to evolve especially given the variable patterns and drivers of urbanization in different regions of the world as well as the different environmental factors and biodiversity in these regions. Biodiversity monitoring has been shown to be crucial to conservation goals aimed at accessing the state and condition of biodiversity. The Second South African Bird Atlas Project (SABAP2) is a citizen science atlas project which commenced in 2007. Over a decade, SABAP2 has produced a rich source of data, capturing bird distributions in South Africa. This makes SABAP2 a powerful tool for monitoring observed changes in bird communities and by extension biodiversity through time. I examined the effect that urbanization is having on the avian biodiversity in South Africa, one of the most urbanized countries in Africa. My research was focused on the 576 pentads in the four one-degree grid cells (25S 27E, 25S 28E, 26S 27E and 26E 28E) centered on the Gauteng province, referred to as Greater Gauteng region. In addition to being very urbanized, Greater Gauteng is also the most populated area in the country, and is home to 30% of the country’s 51 million people. The region is the most atlased SABAP2 region in the country, with each pentad having a minimum of 11 full-protocol SABAP2 checklists. It thus provide opportunities for the development of tools to monitor the temporal dynamics of bird communities. The first chapter is the general introduction where I did an extensive literature review of the research subject and gave an overview of the data chapters that make up the thesis. In the second chapter, I examined spatial patterns of urbanization and avian biodiversity. I assess avian species composition in the urban and rural areas of Greater Gauteng. I categorized bird data from SABAP2 for Greater Gauteng Urban and Rural subgroups. The dataset for this chapter had 700 bird species. 644 showed no range preference for either urban or rural areas. Five species showed a preference for rural areas while 51 species showed a preference for urban areas. The higher species richness recorded in urban pentads highlights the often overlooked benefits of biodiversity conservation efforts in urban areas such as green spaces and parks, gardens and water bodies. This chapter highlights the need for conservation efforts to be targeted at birds and other biodiversity in urban spaces. It is also raises the need to further promote policies aimed at having conservation efforts incorporated into town planning. In the third and fourth chapters, I used data from SABAP2 to investigate how different protected areas such as Important Bird Areas (IBAs) are to their surrounding areas by demonstrating how different the Devon Grasslands (Chapter 3) and Suikerbosrand Nature Reserve (Chapter 4) IBAs are to their immediate surrounding areas in terms of avian species richness and assemblage. Atlas data from the pentads covering these two IBAs were compared with data from the surrounding pentads. Both IBAs stand out as having more bird species than their immediate surroundings. The simple yet effective method used in this chapters can be applied in identifying potential sites for biodiversity conservation. In the fifth chapter, using a variation of the Shannon-Weiner species diversity index which is known to reach an asymptote rapidly even while species richness keeps increasing, to investigate patterns of spatial distribution of species richness and proportional diversity in Greater Gauteng. The chapter provides insights into pentads with the richest bird communities and also provides a method which can be applied to citizen science data such as SABAP2 to discover areas where particular groups of species, such as waterbirds and threatened species, are concentrated in the region. The sixth chapter examines the relationship between reporting rates of birds and human population in Greater Gauteng. With Greater Gauteng being the most populated region in South Africa, it presented an ideal situation to investigate patterns of correlation between human population and the reporting rates of bird species in the region. Based on the results obtained, the species were grouped into 18 groups categorized by the relationship pattern revealed by species reporting rates and human population. The Seventh chapter follows a similar pattern with chapter six. However, chapter seven, examines patterns between a socio-economic index, mean income per person, and the reporting rates of birds in Greater Gauteng. The eighth chapter is the conclusion. It gives a synthesis of the thesis and presents the implications for conservation of avian biodiversity in Greater Gauteng. Overall, this thesis highlights the contribution of citizen science can make to research. It also makes for a strong case showing fundamental importance of large volumes of data such as SABAP2 data, and the useful information that can be harnessed from this data. The conservation-relevant studies in the chapters of this thesis are a result of the spatial distribution patterns of the avifauna revealed by SABAP2 data from Greater Gauteng. It showed how we can detect changes in species abundance, richness and composition in a pentad or in any area, a method we can extend further to detect when bird species are starting to decline or drop out of the species list for a pentad. The results reported in this thesis provides a rich field of study for future research, especially in the field of urban ecology.
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Nyengera, Reason. "Influence of anthropogenic stressors on the behaviour and mortality of the endangered African penguin." Thesis, Nelson Mandela Metropolitan University, 2014. http://hdl.handle.net/10948/3064.
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This study investigated the potential impacts of several anthropogenic stressors on the movement and survival of African penguins in Algoa Bay, taking into account prey availability and environmental conditions (sea surface temperature and chlorophyll productivity). The primary drive for the study was based on the seismic exploration, which took place in the habitat of the endangered African penguin. The research was also carried out to understand how pelagic fishing and prey availability influence the broader behavioural and mortality aspects of penguins. To achieve this goal, I used monthly beach surveys to assess seabird mortality, admissions of penguins in rehabilitation centres and the monitoring of breeding penguins’ movement at sea through individual GPS tracking. In addition, prey distribution and abundance were monitored with acoustic surveys to assess potential changes in relation anthropogenic stressors. Breeding African penguins did not react dramatically to seismic activities, except on St Croix Island where they changed their foraging direction during the seismic period. There was no evidence of a siginficant increase in African penguin carcasses encountered or strandings along the beaches during the period of seismic activity. However, a sharp increase in encounter rate was recorded soon after seismic operations, which may potentially indicate a delay between the effect of seismic activities on penguin mortality and the encounter of the related carcasses after the operation. However, the impact of seismic surveys on penguins may be long-term rather than short term, and additional studies would be needed to reveal long-term effects of seismic activities, if any. Foraging effort of breeding African penguins increased substantially in the presence of commercial fishing activities within close proximity to the colonies. To a greater extent, at-sea movement patterns and counts of beach cast carcasses were largely influenced by prey availability. Penguins spent more time at sea, traveled longer and covered a larger foraging area during periods of relatvely low pelagic fish abundance. There was also a sharp increase in African penguin mortality during periods of low prey availability in the Bay. However, environmental conditions showed some influence over these interactions. Foraging effort of breeding African penguins increased substantially in the presence of commercial fishing activities within close proximity to the colonies. To a greater extent, at-sea movement patterns and counts of beach cast carcasses were largely influenced by prey availability. Penguins spent more time at sea, traveled longer and covered a larger foraging area during periods of relatvely low pelagic fish abundance. There was also a sharp increase in African penguin mortality during periods of low prey availability in the Bay. However, environmental conditions showed some influence over these interactions. For example a red tide event during in period of low prey availability, made it difficult to understand impacts of prey on penguins difficult. Both anthropogenic stressors and environmental conditions influenced African penguins’ behaviour and survival. Due to the worrying trend of African penguins in South Africa for the past few years, all conservation management efforts to increase penguin numbers and limit their mortality are necessary. This study highlights the negative impact of industrial fishing on this Endangered species and the rapid increase in mortality of penguins during times of low prey availability. A network of Marine Protected Areas would certainly increase food availability to African penguins by limiting competition with fisheries, and contribute to increasing the population numbers.
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Mangachena, Joy Rumbidzai. "Response of bird assemblages to the invasion and clearing of alien trees in the Western Cape, South Africa." Thesis, Cape Peninsula University of Technology, 2016. http://hdl.handle.net/20.500.11838/2583.
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Thesis (MTech (Conservation and Marine Sciences))--Cape Peninsula University of Technology, 2016.Invasive alien plant species pose a major threat to global biodiversity by displacing native vegetation and transforming habitats. In South Africa, invasive alien plants have become a major component of most habitats. River systems are particularly affected owing to their dynamic nature and to anthropogenic activities. This has resulted in fynbos riparian scrub vegetation being replaced mainly by Acacia and Eucalyptus species, with serious ecological and economic impacts. The presence of alien trees along river banks leads to a reduction in native plant species richness and their high water consumption adds on to the existing water challenges in an already dry country. However, with regards to native fauna, it largely remains unknown both at small or large spatial scale, whether alien trees provide additional habitat which increases biodiversity, or if their presence leads to a reduction of native biodiversity. Impacts on water supply have led to large-scale clearing of invasive alien trees from riparian zones by the government through the Working for Water (WfW) programme. Monitoring and evaluation studies carried out after clearing are not well-rounded and mostly focus on vegetation response to clearing. Although some of these studies have reported successful restoration through passive methods, ecosystem recovery remains partial. There is evidently a lack of information regarding the response of animal communities to invasive alien plant clearing. Therefore, the main objective of this thesis was to investigate bird assemblage response to alien tree invasion and clearing. As a study system, I used the riparian area of the Berg River within the fynbos biome of the Cape Floristic Region, South Africa. The area historically consisted of renosterveld vegetation characterised by a matrix of shrubs and a high diversity of geophytes but relatively poor avifaunal diversity. This area is heavily affected by invasive alien trees and shrubs including Eucalyptus camaldulensis. I employed bird assemblages as an indicator, and used fixed-point bird counts to compare bird species richness and bird abundance between invaded and near-pristine habitats. Invasion by E. camaldulensis significantly reduced bird species richness and abundance. In particular, nectarivores and frugivores, which play important mutualistic roles in the fynbos, were reduced and unexpectedly; there were fewer raptors in invaded areas. I proceeded to carry out a space for time substitution, comparing plant and bird assemblages in invaded sites, near-pristine sites and in sites cleared in 2005, 2007, 2008 and 2014. A general increase in bird species richness and bird abundance with time since clearing exists with bird assemblages in cleared sites being similar to those in near-pristine sites. However, bird assemblages in cleared sites have not yet fully recovered a decade after clearing and four native plant species are still absent. In the third part of my thesis I assessed the impacts of invasive alien plants on bird assemblages at a larger spatial scale. The different responses shown by bird assemblages to invasive alien plant cover depended on the intensity of invasion, spatial scale and other land uses. From a bird’s eye view, this study supports the current clearing by WfW given the significant negative effects of invasive alien plants on bird diversity both at plot and large spatial scales. However, passive restoration is unsuccessful in restoring the full complement of plants and birds, therefore, active restoration should be considered. To limit the cost, I suggest a focused restoration approach of selected keystone tree species which can assist to establish a functional native ecosystem.
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Kieck, Marius Burger. "Comparative impacts of fragmentation on birds in two bioregions in a biodiversity hotspot, the Cape Floristic Region." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/1627.
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Thesis (MScConsEcol (Conservation Ecology and Entomology))--University of Stellenbosch, 2009.Habitat loss and fragmentation are two of the most pressing threats to biodiversity. Avifaunal diversity and integrity is under immense pressure from these two processes. We have made major advances in our understanding of avifaunal responses to habitat fragmentation, but mostly focus on either fragment scale and/or landscape scale influences of fragmentation on birds. A more comprehensive approach to assessing the impacts of fragmentation was used in this study. The avifaunas of two different geographical regions and bioregions were surveyed and a multiscale analysis of avifaunal responses to fragmentation was attempted. The study sites include the West Coast and East Coast Renosterveld Bioregions in the Cape Floristic Region, South Africa. Assemblage shifts, feeding guild compositional changes, species abundance variation and species persistence were examined at the three spatial scales. Time- and distance-restricted point counts were used to document birds that were directly dependent on the habitat fragments. Forty fragments were selected in each bioregion and a once-off snapshot of the avifaunal richness and diversity was obtained. Results indicate that the avifauna of the two bioregions responded differently to habitat fragmentation. In the East Coast Renosterveld Bioregion, the assemblages, guild composition and species abundances were most accurately predicted by landscape configuration. An assemblage shift occurred at 20 ha fragment area, compared to the 50 ha fragment area threshold of the West Coast Renosterveld Bioregion’s avifauna composition. In the West Coast Renosterveld Bioregion, fragment area was the better predictor of assemblage, guild composition and species abundances. However in both bioregions, the persistence of common species was equally sensitive to area and landscape scale effects.
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Lloyd, Penn. "A study of the Pycnonotus bulbul species complex in Southern Africa." Thesis, Rhodes University, 1995. http://hdl.handle.net/10962/d1005470.
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The three Pycnonotus bulbuls endemic to Africa, P. barbatus, P. nigricans and P. capensis, occupy mutually exclusive distributions in southern Africa. These species are closely related and appear to occupy very similar ecological niches, only in different regions. Using a multifaceted approach, this study attempts to explain the ecology of this species complex. All three species show similar physiological responses to temperature extremes, and are therefore unlikely to be directly limited by environmental temperature. However, their distributions are highly correlated to a complex of environmental variables, particularly winter minimum temperatures, the coefficient of variation in mean annual rainfall, and the seasonality of rainfall. This combination of environmental parameters can be used to predict the distributions of at least one of the species, P. nigricans, accurately. An analysis of the vocalizations and behaviour of the three species revealed that, whilst P. capensis has a number of recognizably different vocalizations, those of P. barbatus and P. nigricans are very similar. The three have nearly identical behaviours, particularly courtship and pre-copulatory behaviours. The mate recognition systems of the three are therefore extremely similar. P. barbatus is territorial during the breeding season, and exhibits highly structured-variation in male territorial song at the level of the local neighbourhood. The literature pertaining to song dialects is reviewed, and a new hypothesis is postulated to explain song-matching in terms of neighbour/stranger discrimination and the possible existence of cooperative territory defence. A survey of the eastern Cape region, where all three species come into contact, showed that extensive hybridization is taking place between each species pair. Phenotypically, this hybridization is restricted to narrow hybrid zones, that are considered to be stable in both time and place. The evolutionary and ecological significance of these zones to the distributions of the species is discussed, and it is proposed that the zones are maintained by selection acting on differentially-adapted genomes along an environmental gradient.
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Mokotjomela, Thabiso Michael. "A comparison of bird foraging preferences for fruits of indigenous and alien shrubs and seed dispersal potentials in the Cape Floristic Region." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20374.
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Thesis (PhD)--Stellenbosch University, 2012.ENGLISH ABSTRACT: This study tested the proposal that fleshy-fruited alien shrubs competed more effectively for avian dispersal services than indigenous shrubs. Several different quantitative measures of increasing complexity were applied to test bird foraging preferences for fruits of two established alien shrubs (Lantana camara, Solanum mauritianum), two emergent alien shrubs (Myoporum tenuifolium, Pittisporum undulatum) and two indigenous shrubs (Chrysanthemoides monilifera, Olea europaea subsp. africana). Overall the simplest quantitative measure, namely that of bird visitation frequency identified foraging preferences of individual bird species for fruits of alien and indigenous shrubs. Moreover, even the more complex measures of numbers of foraging birds, foraging times and products of these in the computed consumption intensity and seed dispersal efficiency were positively correlated to visitation frequency. There was a distinct preference of several, especially heavily fugivorous, bird species for fruits of established alien than indigenous shrubs and several moderately fugivorous bird species preferred fruits of emergent than established alien shrubs. Intricate photographic and experimental approaches were applied to obtain precise numerical data on seed removal rates by birds from the alien and indigenous shrubs. Deficiencies associated with the experimental approach included its inability to discriminate between asynchronous fruit production and fruit ripening, individual foraging bird species, and fruit consumption by other fruit foraging vertebrates. The advantages of the photographic approach were in its provision of a detailed permanent record of individual foraging bird species, their total numbers and precise foraging times and the proportions of whole fruits consumed, as well as other behavioural foraging traits. Tested also was the proposal that frugivorous birds remove larger amounts of fruits from plants with high fruit production and nutritional contents and that the germination of the bird-ingested seeds is enhanced. In compliance with this proposal, canopy fruit mass and monosaccharide content were all positively correlated with the total numbers of seeds removed by birds and viable seeds excreted by birds. Only defecated seeds of the indigenous C. monilifera and alien L. camara displayed enhanced germination following their ingestion by birds Seed dispersal distances of alien and indigenous shrubs by birds were estimated from published records of bird body masses, gut retention times of consumed seed and flight speeds. Estimated seed dispersal distances ranged between 0.41 and 0.81 km for the subset of heavily and moderately frugivorous bird species examined. However, their foraging distances derived from birdring recapture records were much greater, these peaking between 2.5 and 50 km in some heavily frugivorous bird species. It is concluded 1. that bird visitation frequency be applied as the most efficient and practical quantitative measure for gauging bird foraging preferences in future surveys which should involve large complements of indigenous, emergent and established alien species, 2. that flight speeds and gut passage times of ingested alien and indigenous seeds need to be measured in local bird species so long distance seed dispersal potentials can be more precisely determined and 3. that control measures should be focused on eradicating especially emergent alien species with fleshy fruits from urban environments to prevent their transport by birds into adjacent natural areas.
AFRIKAANSE OPSOMMING: Hierdie studie het die voorstel getoets dat uitheemse vlesige-vrug struike meer effektief kompeteer vir voël verspreidingsdienste as inheemse vlesige-vrug struike. Verskeie kwantitatiewe maatstawwe van toenemende kompleksiteit was toegepas om die voedingsvoorkeure van voëls vir vrugte van twee gevestigde uitheemse struike (Lantana camara, Solanum mauritianum), twee ontluikende uitheemse struike (Myoporum tenuifolium, Pittisporum undulatum) en twee inheemse struike (Chrysanthemoides monilifera, Olea europaea subsp. africana) te toets. Algeheel het die eenvoudigste kwantitatiewe maatstaf, naamlik voël besoek frekwensie, voedingsvoorkeure van individuele voël spesies vir vrugte van uitheemse en inheemse struike geïdentifiseer. Addisioneel het die meer komplekse maatstawwe soos voël getalle, voedings tye, asook produkte hiervan in die berekende verbruiks intensiteit en saadverspreiding effektiwiteit almal positiewe korrelasies met besoek frekwensie. Predominant vrugtevretende voël spesies het ‘n duidelike voorkeur getoon vir vrugte van gevestigde uitheemse eerder as inheemse struike. Verskeie meer gematigde vrugtevretende voël spesies het egter vrugte van ontluikende eerder as gevestigde uitheemse struike verkies. Ingewikkelde fotografiese en eksperimentele benaderings was gebruik om presiese numeriese data van saad verwyderingstempo’s deur voëls vanaf die bestudeerde struike te bekom. Tekortkominge geassosieerd met dié eksperimentele benadering sluit in die onvermoë om te onderskei tussen asinkrone vrug produksie en vrug rypwording, individuele kos soekende voël spesies, asook vrug verbruik deur ander vrugvretende werweldiere. Die voordele van die fotografiese benadering was die verskaffing van ‘n gedetailleerde permanente rekord van individuele kos soekende voël spesies, hul totale getalle, presiese voedingstye, proporsie heel vrugte verbruik, asook ander voedingsgedrag eienskappe. Ook getoets was die voorstel dat vrugtevretende voëls groter hoeveelhede vrugte verwyder van plante met hoë vrugproduksie en hoë nutriënt inhoud, en dat ontkieming van voëlingeneemde sade verhoogd is. In nakoming met die voorstel, was blaredak vrugte massa en monosakkaried inhoud albei positief gekorreleer met totale aantal sade verwyder deur voëls en lewensvatbare sade uitgeskei deur voëls. Slegs sade van die inheemse C. monilifera en die uitheemse L. camara het verhoogde ontkieming gewys na inname deur voëls. Saadverspreiding afstande van uitheemse asook inheemse struike deur voëls was bepaal vanaf gepubliseerde rekords van liggaams massa, saad behoud tye in die maag na inname, en vliegspoed. Beraamde saadverspreiding afstande het gestrek tussen 0.41 en 0.81 km vir dié subgroep van predominant en gematigde vrugtevretende voël spesies bestudeer. Nogtans was voedings afstande, afgelei van geringde voël hervangs rekords, veel groter, en het gepiek tussen 2.5 en 50 km vir sommige predominant vrugtevretende spesies. Gevolglik weet ons nou dat 1) voël besoek frekwensie toegepas kan word as die mees effektiewe en praktiese kwantitatiewe maatstaf vir die bepaling van voël voedings voorkeure in toekomstige opnames waar komplementêre groepe inheemse, ontluikende en gevestigde uitheemse spesies bestudeer word; 2) vliegspoed en maag passeer tye van ingeneemde uitheemse en inheemse sade gemeet moet word in plaaslike voël spesies sodat langafstand saadverspreiding potensiaal meer presies bepaal kan word; en 3) beheer maatstawwe moet fokus op die verwydering van spesifiek ontluikende uitheemse vlesige-vrug spesies vanuit stedelike omgewings, om sodoende saad vervoer deur voëls na naasliggende natuurlike areas the verhoed.
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Martens, Francis Rae, and Colleen Downs. "The spatial ecology and roost site selection of fledging cape vultures (Gyps coprotheres) in the Eastern Cape, South Africa." Thesis, Nelson Mandela University, 2018. http://hdl.handle.net/10948/15875.
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The Cape Vulture (Gyps coprotheres), a southern African endemic, is a species currently listed on the IUCN Red List as “Threatened” due to its 66-81% decline over the past 50 years. South Africa and Lesotho hold 90% of the global population, which are focused at two core areas, namely northern central South Africa and eastern South Africa. This species provides important ecological services yet faces numerous anthropogenic threats. An emerging threat in the south eastern part of South Africa is that of wind energy development. Understanding the movement and roosting behaviour of the Cape Vulture may mitigate potential collisions if areas of high use are avoided. Juvenile Cape Vultures, who naturally suffer high mortality rates, are known to forage extensively over a wider landscape and as a consequence may face a greater assortment of threats. The overall aim of this study therefore was to determine the ranging and roosting behaviour of juvenile Cape Vultures in the Eastern Cape Province, South Africa. In order to achieve this aim, i) the ranging behaviour and habitat use were determined and ii) roost sites and factors that influence roost site selection were determined. Using five juvenile Cape Vultures tagged with Global Positioning System (GPS/GSM) transmitters, home range sizes, distance travelled from the nest and habitat use were determined. Home range was determined through kernel density estimates and distance travelled from the nest was determined through the Euclidean distance. Habitat use was determined by overlaying the home range size onto a merged layer of all protected areas and the National Land Cover Database of South Africa. To determine roost sites, data from the tagged vultures were split into encamped and exploratory movements using a mixture model in a cluster analysis setting. Encamped movements were associated with roost sites. Roost density was determined around the natal colony using predetermined buffer sizes and a generalised linear mixed model (GLMM) fitted to the data. Conditions considered favourable for roost sites were based on previous research conducted on cliff-nesting species and a GLMM conducted. Juveniles increased their home range progressively for the first two months, then exhibited a rapid increase in size associated with dispersal from the colony. Distance from the nest increased rapidly following the dispersal period. Protected areas and woody vegetation were areas of preferred habitat. The highest density of roosts for juveniles was located within 20 km’s from the breeding colony and decreased further away. Roost sites that were favoured for juveniles and adult birds were those that were located close to colonies, had low accessibility to terrestrial predators and were in areas of high wind speed. The orientation of the cliff into the prevailing wind direction was also a determining factor. Roosting sites and foraging areas are important spatial determinants of Cape Vulture behaviour and the identification of such areas can help with conservation management. With the additional threat of wind development in areas highly utilised, wind farms located too close to colonies could have a devastating impact on the Cape Vulture population. Therefore, this study highlights the importance of conservation buffer zones as no-go areas for wind energy development around vulture colonies.
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Van, Eeden Daniël Greyling. "Aspects of the ecology and conservation status of selected wildlife in and around Tembe Elephant Park, KwaZulu-Natal, South Africa." Connect to this title online, 2005. http://upetd.up.ac.za/thesis/available/etd-03232007-095314/.
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Boomker, Jacob Diederik Frederik. "Parasites of some free-living wild animals and freshwater fish species in South Africa." Thesis, Pretoria : [s.n.], 2009. http://upetd.up.ac.za/thesis/available/etd-12032009-194518/.
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Jeal, Corey. "The impact of a 'trough' Concentrated Solar Power facility on birds and other animals in the Northern Cape, South Africa." Master's thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/25010.
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The environmental impacts of solar power generation and particularly Concentrated Solar Power (CSP) are not well understood. There have been reports of birds injured and killed by concentrated solar radiation at power 'towers' and from collisions with mirrors at both tower and 'trough' facilities. This study assesses the impacts of a utility-scale 50 MW 'trough' CSP facility - Bokpoort CSP Power Plant - in the Northern Cape, South Africa. To assess the changes in functional and structural changes in bird communities, bird counts in the solar fields (mirror arrays) were compared with transects from rangelands adjacent to the CSP plant. Invertebrates were sampled with sticky and pitfall traps adjacent to the power block, in the solar fields, and in the rangeland landscape to assess changes in invertebrate communities. There were significant changes in bird distribution across the landscape with more species richness and two orders of magnitude greater abundance in the rangeland compared to the solar fields. Fewer invertebrates were caught, but with a greater taxonomic richness in rangeland compared to the power block and solar field. The facilities' evaporation ponds created novel wetland habitat for birds; 23 species were recorded that would have been absent from the area prior to construction, including three breeding species. The solar fields were surveyed for bird injuries or fatalities over 3 months; only eight dead birds were found, all but one was too old to determine the cause of death (>1 month); the remaining carcass likely died from a mirror impact. Western Barn Owls (Tyto alba) made up half of the mortalities. Biases in mortality estimates due to searcher efficiency and scavenger removal were substantial only for small birds. Twenty-one animals (3 reptiles, 12 mammals, 6 birds) likely drowned in the evaporation ponds after being unable to escape. The recorded mortalities were very low in comparison with similar studies on CSP facilities. No threatened or endangered species were killed. Overall, the facility had a low impact on bird populations, but the drowning risk posed to animals by evaporation ponds requires mitigation. The negative impacts observed could be minimised through careful site selection of solar facilities and careful design and mitigation considerations particularly with regard to evaporation and water ponds in arid areas such as the Northern Cape.
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Blake, Justin David. "The ichthyofauna and piscivorous avifauna in a small temporarily open/closed Eastern Cape estuary, South Africa." Thesis, Rhodes University, 2010. http://hdl.handle.net/10962/d1005395.
Full textAbstract:
The spatial and temporal patterns in selected components of the ichthyofauna and piscivorous avifauna in the small temporarily open/closed Riet River Estuary located on the eastern seaboard of southern Africa was investigated monthly over the period August 2005 to July 2006. The ichthyofauna within the littoral zone of the estuary was sampled using a 5 m seine net (8 stations) while a 30 m seine net (4 stations) was employed to sample the fish in the channel. Bird counts were made along repeat transects along the length of the estuary. Total ichthyofaunal abundances and biomass ranged between 1.60 and 8.67 individuals m⁻² and 0.45 to 21.76 g wwt m⁻² within the littoral zone, and between 0.08 and 0.44 individuals m⁻² and 0.58 and 36.52 g wwt m⁻² in the channel of the estuary. The highest values were generally recorded during the summer months. Results of the numerical analysis indicated that the breaching events recorded over the study period did not lead to a common trend in the ichthyofaunal community. In the absence of a link to the marine environment, the ichthyofaunal community in the littoral zone was numerically dominated by the estuarine resident species, Gilchristella aestuaria and to a lesser extent by Glossogobius callidus, which collectively accounted for ca. 54% of the total ichthyofauna sampled. The establishment of a link to the marine environment coincided with increased numbers of marine breeding species including Atherina breviceps and Rhabdosargus holubi to total fish counts within the estuary. Hierarchical cluster analysis did not identify any spatial patterns in the community structure of the ichthyofauna in the littoral zone or channel zone of the estuary, which could likely be linked to the absence of any distinct horizontal patterns in salinity and temperature within the system. A total of thirteen piscivorous bird species was recorded over the study period. Of the recorded species, six species were wading piscivores, four species were aerial divers and the remaining three species were pursuit swimmers. There were no significant correlations between the estimates of the ichthyofaunal abundance and biomass and bird numbers evident during the study (P> 0.05 in both cases). The Reed Cormorant (Phalacrocorax africanus) was the dominant species throughout the study, with a mean of 8.25 (SD ± 7.90) individuals per count. Mean values of the Pied Kingfisher (Ceryle rudis) and Giant Kingfisher (Megaceryle maximus) were 3.42 (SD ± 1.20) and 1.17 (SD ± 0.60) individuals per count, respectively. The remaining species revealed mean values < 0.5 individuals per count. The highest bird numbers were recorded in winter reflecting the migration of large numbers of the Reed Cormorant into the system. Breaching events were associated with a decrease in total bird numbers, which was most likely due to loss of potential foraging habitat (littoral zone) for waders resulting from reduced water levels. Monthly food consumption by all piscivorous birds revealed large temporal variability, ranging from 26.35 to 140.58 kg per month. The observed variability could be linked to mouth phase and bird numbers.
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Knight, Richard Spencer, and Richard Spencer Knight. "Aspects of plant dispersal in the southwestern Cape with particular reference to the roles of birds as dispersal agents." Doctoral thesis, University of Cape Town, 1988. http://hdl.handle.net/11427/23272.
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The dispersal of plants with particular attention to the roles birds play as dispersal agents was studied in the southwestern Cape, South Africa from 1983 to 1985. The research was organized as ten inter-related studies, each with an independent data base. Each chapter focused on a different scale of plant dispersal processes ranging from regional assemblages of plant species to individual species. At the largest scale, the seven vegetation types commonly occurring in the southwestern Cape were examined for incidence of vertebrate-dispersed plants. Coastal Thicket and Afromontane Forest were found to be the richest in these species. The colonization of vertebrate-dispersed plants was examined in an artificially cleared area of Mountain Fynbos vegetation. Enhanced densities of vertebrate-dispersed species were found in areas where perches had been provided. The seasonal availability of vertebrate-dispersed species was found to be most continuous in Coastal Thicket vegetation. Fruit displays of vertebrate-dispersed indigenous plants were found to vary from those that were sporadic and inconspicuous, to those that were conspicuous and predictable, whereas those of alien plants were usually large and conspicuous. Avian use of these fleshy fruits in Coastal Thicket was examined and found to be proportional to their availability. A study of fruit presentation in relation to leaf number and stem thickness suggested that sessile, stem attached fruits have fewer local leaves at time of ripening than fruits which are presented in panicles. This may enhance accessibility and conspicuousness of stem attached fruits for dispersal by birds. Four autecological studies tested certain predictions arising from models developed to describe fruit/frugivore interactions. The dispersal of the alien Acacia cyclops seeds by the indigenous Black Korhaan Eupodotis afra suggested that successful fruit/frugivore relationships are not necessarily the product of reciprocal evolution. The study on Chrysanthemoides monilifera found that efficient dispersal systems are not limited to plants producing small quantities of lipid-rich fruits and to dispersal by obligate frugivores. The abiotic dispersal of Quercus robur was found to be efficient in relation to vertebrate-dispersal. The study on Protasparagus aethiopicus found that the morphology of fleshy fruits may also reflect attempts to overcome the effects of non-dispersing seed predators. 1It is concluded that a gradient from a predictable to unpredictable fruit availability provides a better basis for studying fruit/frugivore interactions than the coevolutionary models. previously presented.
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Terörde, Anja Isabel. "Variation in the use of intermittently open estuaries by birds : a study of four estuaries in the Eastern Cape, South Africa." Master's thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/6209.
Full textAbstract:
Includes abstract.Includes bibliographical references (leaves 87-99).
The main objective of this study was to describe the use of intermittently open estuaries (IOEs) along a section of the Eastern Cape coast by waterbirds, and the factors that influence avifaunal community composition in space and time. The study area consisted of four IOEs of varying sizes within a 40 km stretch of coastline in the warm temperate coastal biogeographical region of South Africa.
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Kotoane, Mapule. "Modelling risk of Blue Crane (Anthropoides paradiseus) collision with power lines in the Overberg region." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/50024.
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Thesis (MA)--Stellenbosch University, 2004.ENGLISH ABSTRACT: This study addresses the problem of Blue Crane (Anthropoides paradiseus) collisions with power lines in the Overberg region, home to approximately 50% of South Africa's national bird's global population. The low visibility of power lines against the landscape is considered to be the major cause of collisions. These claim at least 20 birds annually, which is a considerable loss to a vulnerable species. For this study, expert knowledge of the Blue Cranes' biology, general behaviour and use of its habitat were compiled. These were then translated into rules that were integrated into a Geographic Information System (GIS) to establish a predictive model, which attempts to identify and quantify risk power lines that Blue Cranes are most likely to collide with. The criteria that were considered included landscape proximity of power lines to water bodies arid congregation sites, land cover, power lines orientation in relation to predominant wind directions (North Westerly and South Easterly) and visibility of the power lines against the landscape. The power lines were ranked as highest, high, medium, low and no risk. It is recommended that this classification be used to prioritize the proactive marking of power lines with bird flappers in order to reduce collisions. The results show that 27% of the power lines in the study area pose the highest risk and should therefore be marked immediately. The power lines classified as high (1%), medium (28%) and low risk (21 %) should be marked over short, medium and long term, respectively .. The study demonstrated the potential of GIS in the conservation of Blue Crane. The GIS model developed in this study can be applied in areas of similar habitat such as the Swartland or with some modifications in a slightly different habitat such as the Karoo. It is envisaged that the results of this study will be of great value to the ESKOM (South African Electricity Commission) and Endangered Wildlife Trust (EWT) Partnership and conservation authorities in the effort to save the Blue Crane.
AFRIKAANSE OPSOMMING: Hierdie studie het die probleem van botsings deur Bloukraanvoëls met kraglyne in die Overberg-omgewing van die Wes-Kaap ondersoek. Die Overberg-omgewing huisves ongeveer 50% van Suid Afrikaanse nasionale voël se wêreldbevolking van Bloukraanvoëls, en aangesien kraglyne normaalweg nie maklik sigbaar is teen die landskapsagtergrond nie, verhoog dit, tesame met die biologiese eienskappe van Bloukraanvoëls, die waarskynlikheid dat die voëls met kraglyne sal bots. Hierdie botsings met kraglyne eis minstens 20 Bloukraanvoëls per jaar, wat 'n aansienlike en beduidende aantal vir 'n kritiese bedreigde spesie is. Die studie het gepoog om spesialiskennis oor Bloukraanvoël-biologie, algemene gedrag en habitatgebruik, om te sit in 'n stel reëls, wat in 'n Geografiese Inligtingstelsel (GIS) geïntegreer is om 'n voorspellingsmodel te bou. Hierdie voorspellingsmodel is aangewend om kraglyne wat 'n hoë risiko vir Bloukraanvoëls inhou, te identifiseer en die waarskynlikheid vir botsings te kwantifiseer. Die model aanvaar dat die volgende omgewingsfaktore in die Overberg-omgewing verband hou met die waarskynlikheid van botsings, naamlik: die nabyheid van kraglyne aan waterliggame of gebiede waar voëls saamtrek, die voorkoms van natuurlike veld, die heersende windrigtings (Noordwes en Noordoos) en lae sigbaarheid van kraglyne teen die donker landskapsagtergrond. Die geïdentifiseerde kraglyne is as eerste-, tweede, derde. en vierderangse prioriteit geprioritiseer om as riglyn te dien vir die proaktiewe aanbring van flappers (wat dit ten doel het om voëlbotsings te verminder) deur ESKOM. Die studie het bevind dat 27% van die kraglyne in die Overberg-omgewing eersterang prioriteite is, en dat hierdie kraglyne onmiddellik gemerk sal moet word. Die tweederang prioriteit kraglyne (1%) saloor die mediumtermyn gemerk word, terwyl die derderangse prioriteit kraglyne (28%) oor die langtermyn gemerk sal word. Die vierde prioriteit kraglyne (21 %) kon oor die langertermyn gemerk word. Die studie het die omvang van die probleem, sowel as die rol van GIS in die bewaring van die Bloukraanvoëls beklemtoon. Die GIS-model wat in die studie ontwikkel en gebruik is, kan in soortgelyke gebiede soos die Swartland, of in ietwat verskillende omgewings soos die Karoo getoets word, met die doelom die habitatvoorkeure van Bloukraanvoëls beter te verstaan en navorsers te help om 'n beter begrip van die model te ontwikkel en sodoende die resultate te verbeter. Dit word voorsien dat hierdie studie en verslag baie belangrik sal wees vir die ESKOM-EWT Vennootskap en ander betrokke bewaringsorganisasies in 'n poging om Bloukraanvoël-bewaring aan te help.
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Wolmarans, Milena Helena Louise. "A flight of fancy in the Chorister Robin-Chat (Cossypha dichroa) : an isotopic standpoint." Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1017207.
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Forested areas have been cited for their highly diverse floral and faunal assemblages, which are currently under threat from anthropogenic activities that restrict their range and deplete the resources produced within these naturally fragmented patches. Historically, up to 67 percent of avifaunal species associated with well-treed areas have undergone localised extinctions, consequentially affecting biodiversity as a measure of species richness and ecosystem functionality. To date, more than 900 of the bird species affiliated with forests are under threat and despite the theory surrounding functional redundancy, the mass extinction that is currently underway poses considerable limitations on the ecological integrity of these biomes. In South Africa, indigenous forest (one of the rarest biomes), occurs predominantly in small isolated patches along the eastern escarpment. With mountainous terrain emphasised as ‘prominent hotspots of extinction’, the limited dispersal and habitat sensitivity of montane forest fauna renders these species more prone to localised extinctions. BirdLife International, the IUCN and SABAP2 all indicate reductions in the range and abundance of the Chorister Robin-Chat (Cossypha dichroa) - an endemic forest specialist that is reported to move seasonally between high-altitude forest patches where they breed in summer, and lowland coastal forests where they overwinter. Beyond diet, body morphology and vocalisations, much of the information available on the altitudinal movements of C. dichroa is based on secondary sources and the assumptions therein. This study aimed to investigate the potential utilisation of δ13C and δ15N stable isotopes in determining the dietary niche width and altitudinal movements of C. dichroa. Feathers obtained in forested patches of the Limpopo, KwaZulu-Natal and Eastern Cape provinces exhibited a wide trophic niche width and generalised diet. Strong regional separation is apparent in the isotopic signatures suggesting little movement between provinces. A comparison of 13C-isotopes showed minimal variation that point to a uniformity in the carbon-base utilised by C. dichroa across their range. The 15N-signatures obtained in Limpopo, however, revealed a distinct trophic segregation between the northern-most Chorister populations and their southern counterparts. No altitudinal movements were detected in the isotopic signatures of recaptured Choristers, but more research is needed to investigate the long-term accuracy of these results and the breeding potential of resident Choristers in lowland coastal forests; especially when considering the reduced range and abundance reported for this endemic species.
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Impson, F. A. C. "Biological control of Acacia cyclops in South Africa : the role of an introduced seed-feeding weevil, Melanterius servulus (Coleoptera: Curculionidae), together with indigenous seed-sucking bugs and birds." Master's thesis, University of Cape Town, 2005. http://hdl.handle.net/11427/6272.
Full textAbstract:
Includes bibliographical references (leaves 78-94).Acacia cyclops A. Cunn ex G. Don, or rooikrans (Fabaceae), of Australian origin, is an invasive environmental weed in South Africa where it threatens the unique vegetation of the Cape Floral Kingdom. The invasiveness of the plant in South Africa is, in part, due to its high annual seed-yields, together with the suitable climatic and edaphic factors found here. This study investigated the role of a seed-feeding weevil, Melanterius servulus, which was first introduced into South Africa during 1991, as a biological control agent of A. cyclops seeds, together with the combined effects of indigenous seed-sucking bugs and birds. The weevils utilise filled green pods of A. cyclops for adult feeding, oviposition and larval development and completely destroy seeds during these activities. Examination of the reproductive phenology of A. cyclops showed that seeds are produced annually, during summer and that the presence of filled green pods on the plants coincides with the period of reproductive activity of the weevils. Melanterius servulus populations have established readily at all the original release sites, and within four years of release, damage levels to seeds commonly reached 90%. The weevils have dispersed at an average rate of approximately 2 km per year. Since becoming established in South Africa. the seeds of A. cyclops have been utilised by a variety of generalist vertebrate and invertebrate organisms. Indigenous polyphagous alydid bugs feed on the mature seeds, rendering a portion of the crop inviable when damage levels are high (more than five feeding-punctures per seed). Several bird species are attracted to and feed on the fleshy aril that surrounds theseeds of A. cyclops. Passage of the seeds through the gut of birds enhances germination rates. There is a synergetic relationship between alydids and birds because seeds with low levels of alydid feeding (one to four punctures per seed) germinated more readily after passage through birds than seeds that were not eaten by birds.
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Rogers, Andrew M. (Andrew Munro). "Avian assemblages of invasive Australian Acacia thickets in the Western Cape." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20303.
Full textAbstract:
Thesis (MSc)--Stellenbosch University, 2012.ENGLISH ABSTRACT: Human-modified habitats form increasingly large components of landscapes, threatening biodiversity and creating challenges for conservation. In some cases altered habitats form entirely novel ecosystems that may support new combinations of species and species abundances, and create habitat space in otherwise transformed landscapes. In the Western Cape of South Africa, woody invasive species contribute to landscape-level habitat transformation and form novel ecosystems. Invasive Australian Acacia species are especially problematic in lowland areas where they create dense thickets and substantially transform both biotic communities and abiotic processes. Despite the prominence of Acacia thickets across the Western Cape, their ability to support native fauna is not well understood and the objective of this study was to assess the significance of Acacia thickets as habitat for the region’s avifauna. Birds were surveyed in Acacia thickets in the south-western Western Cape in three seasons to examine species richness, abundance and functional abundance. Furthermore, I examined the extent to which differences in patch-level vegetation structure alter bird communities. Between survey sites and seasons, significant variation was observed in assemblage richness, density, median body size and biomass. Variation in vegetation density, stem density, mean vegetation height and total canopy cover best explained variation in bird assemblages. Eighty species were estimated to utilize Acacia thickets and assemblages had a mean density of 7.78 birds per ha. The most abundant feeding guilds were the mixed feeders and insectivores. The median body size observed was 15.2 g and the body size frequency distribution of all species in Acacia spanned a similar range compared to the body size frequency distribution for the species list for the entire Western Cape. The mean biomass of bird communities was 0.224 kg per ha. Using data on bird density and biomass, Acacia thickets across the Fynbos Biome support and estimated average of over 21 million birds with a combined biomass of over 600 thousand kg. This study found that Acacia thickets in the Western Cape support a subset of the region’s birds with the most abundant species being small mixed feeders, which are also frequently urban-adapted. Compared with other habitat types, Acacia support bird assemblages with moderate species richness and density. This study shows that Acacia thickets, as a novel habitat, provide a significant amount of habitat space in a highly transformed landscape and highlights the need for comprehensive evaluation of altered habitats before assumptions are made about their ecological value.
AFRIKAANSE OPSOMMING: Getransformeerde habitatte maak vermeerderend groot deel uit van die omgewing, dit bedreig biodiversiteit en skep groter uitdagings vir bewaring. In sommige gevalle vorm hierdie getransformeerde habitatte geheel nuwe ekosisteme wat moontlik nuwe kombinasies van spesies en spesie volopheid kan onderhou. Verder skep nuwe ekosisteme habitat spasie in anders veranderde landskappe. In die Wes-Kaap van Suid-Afrika dra die Australiese Acacia indringer spesies is veral problematies in laagliggende areas, aangesien dit digte ruigtes vorm, asook beide die biotiese gemeenskappe en die abiotiese prosesse aansienlik transformeer. Ten spyte daarvan dat daar volop Acacia ruigtes in die WesKaap is, word min verstaan van hul vermoë om inheemse fauna te onderhou. Die hoofdoel van hierdie studie was om die belang van Acacia ruigtes as habitat vir die area se voëllewe te bepaal. Voël-opnames in die suidwestelike dele van die Wes-Kaap is gedoen in Acacia ruigtes oor drie seisoene, om spesierykheid, volopheid en funksionele volopheid te ondersoek. Verder is die mate waartoe verskille in die plotte van die plantegroei struktuur, die voëlgemeenskappe verander, geondersoek. Daar was aansienlike variasie waargeneem in die spesiesamestelling rykheid, voorkoms digtheid, mediaan liggaamsgrootte en biomassa van die voëls tussen die onderskeie voëlopnaam plotte en die seisoene. Die variasie in plantegroei digtheid, stam digtheid, mediaan plantegroeihoogte en totale kroonbedekking verduidelik hierdie variasie in spesiesamestelling die beste. Tagtig voëlspesies Acacia ruigtes benut en die populasiesamestelling het ‘n gemiddelde digtheid van 7,78 voëls per ha. Die mees algemene voel-voeding-guldes was die gemengde-voedsel-vreters en insekvreters. Die median liggaamsgrootte waargeneem was 15,2 g en die liggaamsgrootte frekwensieverspreiding van alle spesies in Acacia ruigtes is ooreenkomstig met die liggaamsgrootte frekwensieverspreiding vir die spesielys vir die hele Wes-Kaap. Die gemiddelde biomassa van voel gemeenskappe was 0.224 kg per ha. Acacia ruigtes oor die fynbosbioom wat ‘n geskatte gemiddelde van meer as 21 miljoen voels ondersteun, met ‘n gesamentlike biomassa van meer as 600 duisend kg. Hierdie studie het bevind dat Acacia ruigtes in die Wes-Kaap ‘n onderafdeling van die streek se voels ondersteun, met die mees algemene spesies as die klein gemengde-voedsel-vreters, wat ook dikwels stedelik aangepas is. In vergelyking met ander habitattipes ondersteun Acacia ruigtes voel samestellings met matige spesierykheid en digtheid. Hierdie studie toon dat die Acacia ruigtes, as ‘n nuwe habitat, ‘n beduidende hoeveelheid habitat ruimte in ‘n hoogs getransformeerde omgewing skep en beklemtoon die behoefte aan ‘n omvattende evaluering van veranderde habitatte, voor aannames gemaak word oor hul ekologiese waarde.
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Derbyshire, Walter. "Game meat production in the Xhariep district of the Free State province : evaluating and optimising resources." Thesis, [Bloemfontein?] : Central University of Technology, Free State, 2011. http://hdl.handle.net/11462/137.
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Thesis (D. Tech. Environmental health) -- Central University of technology, Free State, 2011In addition to one national park and six nature reserves, the Free State Province boasts several privately owned game reserves, as well as game farmers and commercial stock farmers who keep game. A survey conducted in 1985 showed that the majority of game could be found in the Xhariep District situated in the southern and south-western parts of the province. Game export abattoirs and processing facilities are situated in provinces other than the Free State, which results not only in an outflow of game carcasses for export purposes, but also a loss of employment opportunities and opportunities for the generation of foreign currency from a district (Xhariep) which, from a socio-economic perspective, is seen as deprived. There are 21 non-export highthroughput red meat abattoirs in the province, posing the question as to whether these could be used for the slaughtering of game. This study aimed firstly to compile guidelines for the wild game meat industry regarding the production of wild game meat for the international market and to assess wild game production and utilisation in the Xhariep District through a comprehensive survey of game farming practices, game numbers and species, as well as the utilisation of game through various consumptive and non-consumptive methods. A further aim was to investigate practices at existing slaughter facilities in order to determine their potential to be adapted into wild game meat export facilities and assess such potential via a standardised protocol. The research commenced with an investigation into processing and export requirements for wild game meat in South Africa through a literature study of all EU legislation, directives and other relevant literature on the subject, and provides comprehensive reference material for entrepreneurs and developers in the wild game meat industry. Methodologies utilised included audits to determine the extent to which abattoirs conform to the structural, operational and documentation meat hygiene requirements followed by the development of a novel assessment matrix for measuring the level of compliance of existing abattoirs and their potential to be developed into European Union (EU) export facilities. The survey of the Xhariep area concluded that a significant potential exists for the expansion of the game industry, as several respondents indicated that they were interested in expanding their game production and that they had land available for this purpose. A further indication was that the game would be highly marketable because it was free ranging and could be regarded as organic due to the absence or controlled use of additives and pesticides that could result in chemical residues in the meat. The establishment of a wild game export facility was favoured by nearly 70% of the respondents. The hygiene evaluation of existing slaughter facilities in the Free State Province resulted in six slaughtering facilities being rated as good or excellent, demonstrating the potential to successfully process game meat for the export market. This was tested by utilising the proposed evaluation matrix, which rated the abattoirs most suited to be adapted into game meat processing facilities for export purposes. The value of this approach lies in the fact that it is not only restricted to local markets, but can be utilised internationally by the abattoir industry, as well as the fact that it is not species specific. It should, however, be applied objectively by knowledgeable operators in the industry. It is concluded that institutions in the Free State Province possess the knowledge and ability to not only produce wild game meat, but also to successfully process this commodity through the optimal utilisation of existing high-throughput red meat abattoirs. By utilising existing management skills and affecting relatively minimal adjustments to existing structures, these resources should be utilised to successfully enter the wild game meat export market which should, in turn contribute towards the prosperity of the Xhariep District.
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Mbatha, Khanyisile R. "Using nutritional quality of forage and faeces for predicting sustainable livestock and game stocking rates at Pniel Estates in Northern Cape, South Africa." Thesis, Stellenbosch : University of Stellenbosch, 2006. http://hdl.handle.net/10019.1/1347.
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Thesis (PhD)--University of Stellenbosch, 2010.The aim of the study was to assess the importance of spatial and temporal variation in diet quality and abundance for determining sustainable stocking rates on commercial, communal and game ranches in a semi-arid savanna, with the ultimate goal of avoiding land degradation in the long term, to provide sustainable livelihoods in rangelands and to make policy that will help in managing the available natural resources in the rangelands. Thus, firstly the effects of grazing, fire, nitrogen and water availability on nutritional quality of grass in semi-arid savanna was assessed. Secondly, spatial and temporal variation in plant quantity and quality among management (commercial, communal and game) types and habitat types (open savanna, rocky, shrubby and pans) and stocking rates in different management types were determined. Thirdly, the quality and quantity of variation inside and outside herbivore exclosures among commercial, communal and game management and habitat types in the semi arid savanna were estimated. Fourthly, faecal profiling was used to assess the effects of different management types on diet quality in semi-arid savanna. Lastly, policy based on the results of the present study was formulated.
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Coetzee, Bernard W. T. "Implications of global change for important bird areas in South Africa." Diss., University of Pretoria, 2008. http://hdl.handle.net/2263/29591.
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The Important Bird Areas (IBAs) network of BirdLife International aims to identify sites that are essential for the long-term conservation of the world’s avifauna. A number of global change events have the potential to negatively affect, either directly or indirectly, most bird species, biodiversity in general and associated ecological processes in these areas identified as IBAs. To assist conservation decisions, I assessed a suite of ten landscape scale anthropogenic pressures to 115 Important Bird Areas (IBAs) in South Africa, both those currently placing pressures on IBAs and those that constitute likely future vulnerability to transformation. These threats are combined with irreplaceability, a frequently used measure of conservation importance, to identify the suite of IBAs which are high priority sites for conservation interventions: those with high irreplaceability and are highly vulnerable to anthropogenic threats. A total of 22 (19%) of the South African IBAs are highly irreplaceable and are highly vulnerable to at least some of the pressures assessed. Afforestation, current and potential future patterns of alien plant invasions affect the largest number of highly irreplaceable IBAs. Only 9% of the area of highly irreplaceable IBAs is formally protected. A total of 81 IBAs (71%) are less than 5% degraded or transformed. This result, together with seven highly irreplaceable IBAs found outside of formally protected areas with lower human densities than expected by chance provides an ideal opportunity for conservation interventions. However, all the pressures assessed vary geographically, with no discernible systematic pattern that might assist conservation managers to design effective regional interventions. Furthermore, I used the newly emerging technique of ensemble forecasting to assess the impact of climate change on endemic birds in relation to the IBAs network. I used 50 endemic species, eight bioclimatic envelope models, four climate change models and two methods of transformation to presence or absence, which essentially creates 2400 projections for the years 2070-2100. The consensual projection shows that climate change impacts are very likely to be severe. The majority of species (62%) lose climatically suitable space and 99% of grid cells show species turnover. Five species lose at least 85% of climatically suitable space. The current locations of the South African Important Bird Areas network is very likely ineffective to conserve endemic birds under climate change along a “business a usual” emissions scenario. Many IBAs show species loss (41%; 47 IBAs) and species turnover (77%; 95 IBAs). However, an irreplaceability analysis identified mountainous regions in South Africa as irreplaceable refugia for endemic species, and some of these regions are existing IBAs. These IBAs should receive renewed conservation attention, as they have the potential to substantially contribute to a flexible conservation network under realistic scenarios of climate change. Considering all the global change threats assessed in this study, the Amersfoort-Bethal-Carolina District and the Grassland Biosphere Reserve (IBA codes: SA018; SA020) are the key IBAs in South Africa for conservation prioritisation.Dissertation (MSc)--University of Pretoria, 2008.
Zoology and Entomology
unrestricted
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Ralph, Mark Shaun. "Aspects of the breeding biology of the African penguin on Bird Island, Algoa Bay." Thesis, Nelson Mandela Metropolitan University, 2008. http://hdl.handle.net/10948/840.
Full textAbstract:
It is important to the survival of the Africa Penguin (Spheniscus demersus) population that breeding at the nest site is successful and that large numbers of chicks are fledged into the breeding population. Nest distribution on Bird Island is not random and locality preferences for breeding exist. Although it seems that sufficient area exists on Bird Island for penguin nests, it can hardly be considered as suitable to optimise breeding. During prolonged heat conditions, breeders relocated to nest sites that were sheltered. Nests that were below ground in burrows was the only habitat that did not suffer nest desertion whilst all the other habitat types (including those that were sheltered) experienced 2-3 fold declines in nest numbers. Nests density and the selection of suitable nest sites are significantly influenced by the stage of breeding that the majority of birds are in, yet nests that are shaded, well-ventilated and protected seem to be the most preferred sites for breeding. Adults that attempt to breed are considered then to be in a healthy condition and will usually lay a double clutch (Randell 1983). The frequency of double clutches being laid during the peak breeding attempt was significantly higher compared to the replacement one. Breeding failure was fairly similar to breeding success during the incubation stage for nests with double clutches however, was substantially higher in single clutches. The growth rate of chicks was best fit to the von Bertalanffy growth curve in 90 percent of the cases. The overall growth rate of chicks from double broods was faster than from single broods, however was not significant. A-chicks maitain a high growth rate until they fledged. Yet, the sibling B-chick recorded the lowest growth rate of the successfully fledged chicks and up to until day 30 recorded a similar weight to those chicks that failed to fledge. Contrary to findings of Randall (1983), chicks from single broods delayed fledging, recorded lowest overall growth rates and experienced the greatest weight loss of all groups, yet fledged successfully. In order for chicks to fledge successfully, they needed to obtain a weight of 1060 g before day 30.5 in their growth cycles to avoid death due to startvation later on. Single chicks that are raised from a double cluth, fledged more other than chicks raised from a single clutch. Unfit or ill-adapted breeders that are marginal in the capabilities of raising offspring, already manifest in a small clutch size and offspring unable to obtain adequate weights during the initial stages of growth.
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Curtis, O., G. Malan, AR Jenkis, and N. Myburgh. "Multiple-brooding in birds of prey: South African Black Sparrowhawks Accipiter melanoleucus extend the boundaries." Ibis, 2005. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000999.
Full textAbstract:
Multiple-brooding (raising more than one brood of young in quick succession) occurs infrequently
in raptors and is generally restricted to either smaller species with shorter nesting
periods, co-operative breeders or species capable of capitalizing on conditions of prolonged food
abundance whenever they occur. This paper presents the first recorded cases of multiplebrooding
in the Black Sparrowhawk Accipiter melanoleucus from two distinct locales in
South Africa. In the Western Cape (Cape Peninsula), four attempts to multiple-brood were
recorded in four different years, involving three distinct pairs of birds, and in KwaZulu–Natal
(Eshowe), three distinct pairs of Sparrowhawks successfully multiple-brooded on several
occasions over a 5-year study period. These results establish the Black Sparrowhawk as one
of only two relatively large, monogamous raptor species, and the only specialist bird-eating
raptor, in which multiple-brooding has been recorded with any frequency. The species’
capacity to thrive in human-modified environments (i.e. alien plantations) and particularly
to exploit associated foraging opportunities (e.g. high densities of doves and pigeons in suburban
areas) may, at least partly, account for the instances of multiple-brooding reported
here. We suggest that biologists be more vigilant for cases of multiple-brooding in raptors,
as it is possible that this trait is more common than originally thought and has previously
been overlooked.
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Hansen, Marion. "Birds of a feather flock together race versus gender preference in the South African workplace." Master's thesis, University of Cape Town, 2012. http://hdl.handle.net/11427/5864.
Full textAbstract:
Includes abstract.Includes bibliographical references.
Social Identity Theory proposes that individuals derive part of their identity and their social identity, through their membership in social groups. In order to derive a positive social identity, they attempt to compare themselves more favourably in comparison to members of groups they do not belong to, which may at times leads to discrimination against out-group members. Due to South Africa‟s history of race- and gender-based oppression, it is likely that race and gender are two particularly salient group memberships and that gender- and racebased discrimination are thus particularly prominent. Research has shown that discrimination in the workplace has negative effects, which result in reduced productivity as well as reduced employee engagement and wellbeing. The purpose of this study was to investigate the extent to which employees show a preference for co-workers from their own gender and racial groups and to establish whether their racial or gender bias is stronger.
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Geerts, Sjirk. "Assembly and disassembly of bird pollination communities at the Cape of Africa." Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/6904.
Full textAbstract:
Thesis (PhD (Botany and Zoology))--Stellenbosch University, 2011.ENGLISH ABSTRACT: With the current global decline in pollinators, and the concurrent decline in plant species, pollination research is becoming increasingly important. However, studies outside Europe and North-America and on groups other than insects are needed to make generalisations possible. In this thesis I study how pollination structures plant and bird communities in a biodiversity hotspot, the Cape Floristic Region of South Africa. I show that bird-plant pollination mutualisms are an important ecological factor structuring ornithophilous Proteaceae and nectar-feeding bird communities. This close association between plant and bird communities suggests an important role for community wide pollination mutualisms. How these mutualisms disassemble in reaction to a range of anthropogenic impacts is determined. Firstly, I use experimental manipulation of honeybee density to test whether honeybee farming affects nectar-feeding birds. Hive addition increased honeybee abundance far above natural levels but nectar-feeding bird pollinators were not consistently affected. Secondly, I document the impact of a two lane tar road on the bird pollination community. The two-fold decline found in pollination along roadsides, should have important implications for the way we view and manage road verges for ecological processes. Thirdly, I investigated how fragmentation affects bird-pollination communities by assessing an endangered, bird-pollinated plant, Brunsvigia litoralis. The only flower visitor at the urban sites, the shorter billed Greater Double-collared Sunbird is unable to access the nectar due to a long perianth tube. The longer billed Malachite Sunbird was the sole pollinator of B. litoralis at the rural site, significantly increased seed set. The lack of ecological analogs in these urban fragments might place pollinator specialist plants, such as B. litoralis, at risk. Fourthly, fire is a frequent disturbance in communities of bird-pollinated plants. In a before/after fire observation study and a burnt/unburnt transplant study, birds visited flowers in the “before fire” and “unburnt” areas only. The results are surprising given the large number of bird-pollinated plants flowering in the early post-fire vegetation. Lastly, I find that alien invasive plant species are incorporated into the native pollination community in a spectacular way; sunbirds adapt to a hummingbird-like, hovering lifestyle to obtain nectar. Alien invasive plants greatly increase nectar-feeding bird abundance; in turn, birds enhance seed set in these alien plants. I conclude by asking whether the disassembling of bird pollination communities really matters. To answer this question I report on a decade of demographic data on the geophytic bird-pollinated Brunsvigia orientalis. In the demographic analysis, the elasticity component for reproduction was more important than expected for a long lived plant. Reduced population growth in the shade and a large investment in a winged inflorescence, suggest B. orientalis is a light demanding, well dispersed, gap colonising species. The link between pollination and seed has been made before, but I take this one step further and show that pollination intensity predicts population growth rate. By linking plant demography and pollination, I was able to predict the future of plant populations under variable pollination conditions. The disassembly of bird pollination communities only becomes important for population persistence once the mutualism has almost entirely broken down.
AFRIKAANSE OPSOMMING: Met die huidige globale afname in bestuiwers en die gelyktydige afname in plant spesies, word bestuiwing navorsing toenemend belangrik. Studies buite Europa en Noord-Amerika en op groepe anders dan insekte is nodig on veralgemenings moontlik te maak. In hierdie tesis bestudeer ek hoe bestuiwing struktuur gee and plant en voël gemeenskappe in 'n biodiversiteit hotspot, die Kaapse Floristiese Ryk van Suid-Afrika. Ek wys dat voël-plant bestuiwings mutualismes 'n belangrike ekologiese faktor is in die strukturering van voël bestuifde Proteaceae gemeenskappe en nektar-etende voël gemeenskappe. Hierdie noue assosiasie tussen plant en voël gemeenskappe impliseer 'n belangrike rol vir gemeenskapwye bestuiwings meganismes. Ek bepaal hoe hierdie mutualismes aftakel in reaksie op 'n verskeidenheid van antropogeniese impakte. Eerstens gebruik ek 'n eksperimentele manipulasie van heuningby getalle om te toets of bye boerdery nektar-etende voëls affekteer. Byekorf toevoeging het heuningby getalle laat toeneem tot ver bo natuurlike vlakke maar nektar-etende voël bestuiwers is nie konsekwent beïnvloed nie. Tweedens dokumenteer ek die impakte van 'n twee baan teerpad op die voël bestuiwings gemeenskap. Die twee-malige afname in bestuiwing langs paaie sal belangrike implikasies hê vir die manier hoe ons pad reserwes sien en bestuur met betrekking tot ekologiese prosesse. Derdens bestudeer ek hoe fragmentasie die voël-plant gemeenskappe affekteer deur die bedreigde voël-bestuifde Brunsvigia litoralis te assesseer. Die enigste besoeker in die meer stedelike area, die Groot-rooibandsuikerbekkie, wat 'n korter snawel het, is nie in staat om die nektar te bereik nie, weens 'n te lang blombuis. Die Jangroentjie suikerbekkie met sy langer snawel is die enigste bestuiwer van B. litoralis in die meer landelike area, met 'n betekenisvolle vermeerdering in saad vorming. Die gebrek aan ekologies analogiese spesies in die stedelike fragmente kan 'n risiko inhou vir bestuiwer gespesialiseerde plante soos B. litoralis. Vierdens, vuur is 'n gereelde versteuring van voël-plant gemeenskappe. In 'n voor/na vuur observasie studie en 'n brand/nie-brand verplasing studie, het voëls blomme net in die “voor brand” en “nie-brand” areas besoek. Hierdie resultate is verrassend siende die groot hoeveelheid voël-bestuifde plante wat blom direk na brande. Laastens het ek gevind dat uitheemse indringer plante geïnkorporeer word in die inheemse bestuiwers gemeenskappe op 'n skouspelagtige manier; suikerbekkies pas aan tot 'n kolibri-tipe, fladderende lewenswyse om nektar te bekom. Uitheemse indringer plante het nektar-etende voël hoeveelhede laat toeneem; in reaksie het voëls saad opbrengs vermeerder. In konklusie vra ek of hierdie aftakeling van die voël bestuiwers gemeenskap belangrik is. Om hierdie vraag te antwoord assesseer ek 'n dekade van demografiese data van die geofietiese, voël-bestuifde plant, Brunsvigia orientalis. In die demografiese analises was die elastisiteit komponent van reproduksie belangriker as verwag vir 'n langlewende plant. Verminderde populasie groei in die skaduwee en 'n hoë investering in 'n gevlerkte bloeiwyse suggereer dat B. orientalis 'n lig afhanklike, goed verspreide, gaping koloniserende spesie is. Die skakel tussen bestuiwing en saadvorming is voorheen gemaak, maar ek neem dit een stap verder en wys dat bestuiwings intensiteit populasie groeikoers voorspel. Deur plant demografie en bestuiwing te koppel was ek in staat om die toekoms van populasies onder variërende bestuiwings kondisies te voorspel. Die aftakeling van voël bestuiwings gemeenskappe word slegs belangrik vir populasies se voortbestaan wanneer die mutualisme amper heeltemal verdwyn het.
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Du, Plessis Monique. "The effect of supplementary nectar feeders on bird-plant mutualisms in the Cape Fynbos, South Africa." Master's thesis, Faculty of Science, 2021. http://hdl.handle.net/11427/33642.
Full textAbstract:
Across the world, people feed birds to interact with nature. A variety of feeder types have been developed over the years to target a broad bird community. Attracting nectarivorous birds to gardens using supplementary nectar feeders is a popular human activity across the globe, but few studies have explored its effects on birds and the plants they pollinate. Nectar feeders may have positive effects, facilitating the urban adaptation of nectarivorous birds, and supplementing their diets when floral resources are scarce. However, supplementary feeders may also lure birds away from indigenous vegetation, affecting the rate of visits to bird-pollinated plants, with consequences for seed set. This study is the first to investigate the effect of nectar feeders on an African plantpollinator mutualism. Given that many plant species in the fynbos biome are bird pollinated, this study was conducted in residential gardens and natural vegetation along the urban edge of the Cape Peninsula, South Africa. I carried out a feeding experiment with a matched paired design to answer two main questions: (1) Do nectar feeders affect bird abundance and distribution ranges? If so, (2) do these affect their visitation rates to bird-pollinated plants? I conducted bird surveys to compare relative bird abundance and local distribution patterns for three feeding guilds (i.e., nectar-specialists, nectar-opportunists and non-nectarivores) between feeder and control treatments (Chapter 2). I then tested whether the presence of nectar feeders in gardens affected sunbird visitation rates to two bird-pollinated Erica species (Erica plukenetii subsp. plukenetii and Erica abietina subsp. atrorosea) in the neighbouring vegetation compared to control sites (Chapter 3). In chapter 2, I found that nectar feeders attracted higher densities of avian nectarivores (but not non-nectarivores) to gardens relative to natural vegetation, and decreased their densities in the neighbouring fynbos, even when floral abundance in the neighbouring vegetation was high. In chapter 3, I found that the consequent changes to sunbird distribution patterns (the main pollinators of ericas) seemed to have no influence on visitation rates to E. abietina, but decreased visitation to E. plukenetii flowers within 300 m of gardens with feeders. Thus, nectar feeders may have positive effects for birds themselves by reducing their urban sensitivity but may also have negative effects on the surrounding fynbos ecosystem. Given that nectar feeders appear to compete with the flowers of E. plukenetii, and perhaps those of other birdpollinated species, supplementary feeding may inadvertently threaten bird-plant pollination networks. This issue is particularly concerning in biomes such as the Cape Floristic Region where many bird-pollinated plants occur near urban edges.
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Dignon, Niki. "Quantifying bird damage to wine grapes in the Western Cape of South Africa : a questionnaire-based approach." Bachelor's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/14121.
Full textAbstract:
Bird-wine grape damage is a globally acknowledged problem that has been the subject of considerable research in many wine growing regions. However, despite the Western Cape of South Africa being a major wine grape growing region, very little research has quantified bird damage in this region and very little is known about the extent of the problem. This research aimed to quantify bird damage to wine grapes in four grape growing regions of the Western Cape, through questionnaires. It also aimed to determine the factors that might explain the patterns of damage observed. 102 questionnaires were sent to the wine farms, and 52 were returned. Of the respondents, 71% reported bird grape damage. The amount of damage per wine farm ranged between 0% and 15% of the total rows of vines across a farm. When exploring the factors associated with whether a wine farm experienced bird damage, it was found that the border habitat of a farm was a significant factor. The composition of the border habitat greatly influenced the probability of bird damage. The PCA showed that tall trees, Fynbos and residential areas specifically increased the probability of bird damage. Within farms that experienced damage, it was found that in different vineyard blocks the areas closer to the edge of a vineyard and to trees were significantly more susceptible to bird damage. The most common reported damage-causing bird species were Red-Winged Starlings (Onycognathus morio) and White-Eyes (Zosterops lateralis). Damage was reported to occur mostly one month before harvest and at harvest time. This research provides a baseline for understanding the nature of bird damage in these regions and will aid future quantitative studies aimed at the management of the problem.
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Hofmeyr, Sally D. "Impacts of environmental change on large terrestrial bird species in South Africa: insights from citizen science data." Doctoral thesis, University of Cape Town, 2012. http://hdl.handle.net/11427/12306.
Full textAbstract:
Includes abstract.Large terrestrial bird species, especially cranes and bustards, have adapted to low intensity agriculture to varying degrees, but large-scale industrial agriculture is in general inimical to these species. Cranes are charismatic and well studied, but bustards are retiring and in general cryptically coloured, and little is known of most species. Of South Africa's 10 bustard species, two are endemic and three subspecies are endemic or near-endemic. Six species are threatened or near-threatened. Three crane species occur in South Africa, one of which is near-endemic; all are threatened. This thesis used data from two long-term public participation bird monitoring projects to improve our understanding of six of these 13 species. The first and second Southern African Bird Atlas Projects (SABAP1, 1987-1992, and SABAP2, 2007-) provide two sets of presence/absence data which can be compared. The Coordinated Avifaunal Roadcounts (CAR; 1993-) project provides roadcount data spanning a similar period.
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Stewardson, Carolyn Louise, and carolyn stewardson@anu edu au. "Biology and conservation of the Cape (South African) fur seal Arctocephalus pusillus pusillus (Pinnipedia: Otariidae) from the Eastern Cape Coast of South Africa." The Australian National University. Faculty of Science, 2002. http://thesis.anu.edu.au./public/adt-ANU20030124.162757.
Full textAbstract:
[For the Abstract, please see the PDF files below, namely "front.pdf"] CONTENTS. Chapter 1 Introduction. Chapter 2 Gross and microscopic visceral anatomy of the male Cape fur seal with reference to organ size and growth. Chapter 3 Age determination and growth in the male Cape fur seal: part one, external body. Chapter 4 Age determination and growth in the male Cape fur seal: part two, skull. Chapter 5 Age determination and growth in the male Cape fur seal: part three, baculum. Chapter 6 Suture age as an indicator of physiological age in the male Cape fur seal. Chapter 7 Sexual dimorphism in the adult Cape fur seal: standard body length and skull morphology. Chapter 8 Reproduction in the male Cape fur seal: age at puberty and annual cycle of the testis. Chapter 9 Diet and foraging behaviour of the Cape fur seal. Chapter 10(a) The Impact of the fur seal industry on the distribution and abundance of Cape fur seals. Chapter 10(b) South African Airforce wildlife rescue: Cape fur seal pups washed from Black Rocks, Algoa Bay, during heavy seas, December 1976. Chapter 11(a) Operational interactions between Cape fur seals and fisheries: part one, trawl fishing. Chapter 11(b) Operational interactions between Cape fur seals and fisheries: part two, squid jigging and line fishing. Chapter 11(c) Operational interactions between Cape fur seals and fisheries: part three, entanglement in man-made debris. Chapter 12 Concentrations of heavy metals (Cd, Cu, Pb, Ni & Zn) and organochlorine contaminants (PCBs, DDT, DDE & DDD) in the blubber of Cape fur seals. Chapter 13 Endoparasites of the Cape fur seal. Chapter 14(a) Preliminary investigations of shark predation on Cape fur seals. Chapter 14(b) Aggressive behaviour of an adult male Cape fur seal towards a great white shark Carcharodon carcharias. Chapter 15 Conclusions and future directions.
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Quinn, Laura Penelope. "Assessment of organic pollutants in selected wild and domesticated bird eggs from Gauteng, South Africa / Laura Penelope Quinn." Thesis, North-West University, 2010. http://hdl.handle.net/10394/4286.
Full textAbstract:
Polybrominated flame retardants (BFRs), organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were analysed in eggs of various wild bird species from industrialised areas in South Africa. Eggs were collected during the 2008 – 2009 breeding season, homogenised and sent to the Norwegian School of Veterinary Science (NVH) for gas chromatography-mass spectrometry (GC-MS) analysis. The concentration, contamination profile, and risk assessment were conducted for each pollutant class, while effects of species-specific variation, feeding guild, and feeding habitat were investigated.
Levels of BFRs ranged between 2.6 – 44 ng g-1 wet mass (wm). The predominant congeners were BDE-153, -154, - 183 and -47. Results indicated species, in close contact to humans, had higher levels of BFRs, even at lower trophic levels. Therefore, diet was not the primary route of exposure. High concentrations and the occurrence of nona-PBDE congeners and HBCD indicated exposure to current use BFRs. There were measurable levels of OCPs and PCBs in all eggs analysed. Median OCP concentration ranged from 4.2 – 623 ng g-1 wm. DDE was the predominant compound in all species with the exception of the Crowned Lapwing (Vanellus coronatus) where chlordanes were predominant. This may indicate a species-specific attribute in the metabolic efficiency or diet of the genus, since these findings have been reported elsewhere in literature. Congener profiles indicated historic sources of lindane and DDT, while low levels of p,p’-DDT in al species indicate long-range or atmospheric transport. Even though levels of p,p’-DDE were approaching toxicological thresholds, no eggshell thinning was evident. Concentrations of OCPs and PCBs showed an increase with increasing tophic level. PCB concentrations ranged between 0.9 – 296.4 ng g-1 wm. When studying the metabolic potential of PCBs, metabolic groups showed good agreement with the biodegradability of the individual congeners. Phenobarbital-type (PB-type) inducer PCBs were prevalent, indicating the predominance of less toxic PCB congeners. However, non-ortho PCBs were not analysed. These congeners aslo could impact on the toxic potential of PCBs in wild bird eggs.
Principle component analysis (PCA) indicated that variances within datasets could be attributed to congener profiles within species as they were affected by exposure, diet, position in the food web, and association with human activities. Although the individual groups of organohalogens were below no observed effect levels (NOELs), negative effects could occur through interactions of various compounds with each other, as well as the unique exposure profiles of South African bird populations.
To assess the dietary exposure of low-income human populations living close to large industries, the occurrence of organohalogens was investigated in backyard chicken eggs. Levels of dioxins in these eggs were above the European Union (EU) recommended limits, whereas BFRs and OCPs levels were below levels of concern. Nevertheless, areas where DDT is actively applied to dwellings for malaria control should be urgently investigated.
The presence of measureable levels of all the compounds considered, indicate an environment seriously impacted by anthropogenic activity that in the long term could negatively affect both the environment and human health, if it has not already done so.Thesis (Ph.D. (Environmental Science))--North-West University, Potchefstroom Campus, 2011.
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Duckworth, Greg. "Effects of protected areas and climate change on the occupancy dynamics of common bird species in South Africa." Doctoral thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/29600.
Full textAbstract:
Protected areas are tracts of land set aside primarily for the conservation of biodiversity and natural habitats. They are intended to mitigate biodiversity loss caused by land-use change worldwide. Climate change has been shown to disrupt species' natural distributions and patterns, and poses a significant threat to global biodiversity. The goals of this thesis are to address these important issues, and understand how protected areas and climate change affect the range dynamics of common, resident bird species in South Africa. Common species were used because they have been shown to drive important ecosystem patterns, and a decline in abundance and diversity of common species can indicate drastic declines in ecosystem integrity. This thesis comprises four data chapters; in the first three I model the occupancy dynamics of 200 common, resident bird species in South Africa to gain an understanding of how the proportion of protected areas within a landscape affects common species. For the last data chapter, I examined the effects of protected areas and a changing climate on the range dynamics of Cape Rock-jumper (Chaetops frenatus), a species endemic to the southwestern part of South Africa and whose population is declining rapidly in response to climate change. I modelled its occupancy dynamics in relation to climate, vegetation, and protected area. Overall, my key findings show bird abundances vary widely as a function of protected areas, but on average, bird abundances are higher in regions with a higher proportion of protected areas, compared to regions with a lower proportion. I found that the conservation ability of protected areas was influenced by the type of land-use found in the surrounding landscape. For example, the extent of agricultural land in proximity to a protected area significantly increased the mean abundance of birds in that protected area, whilst the average abundance of most species was not affected by the extent of urban area near protected area. On average, species preferentially colonized and persisted within landscapes with a higher proportion of protected area, compared to landscapes with a lower proportion of protected area. However, protected areas were not able to slow the extinction rate for all species, and the average extinction rate for some groups of species actually increased as the extend of protected areas within a landscape increased. Furthermore, Cape Rock-jumper also preferentially occupied regions with higher proportions of protected area. Despite this, Cape Rock-jumper’s range is predicted to shrink considerably in response to a hotter and mildly drier climate forecast for the region. As a result, Cape Rock-jumper will likely be of conservation concern as the climate over its range continues to change. I conclude that, in general, protected areas are effective at conserving common bird species over a heterogeneous landscape in South Africa, and should be prioritised as key conservation strategies in the future. I further conclude that climate change will be a concern to an endemic species, and to biodiversity in general. This will likely place extra stress on the importance of protected areas to mitigate responses of species to climate change.
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Bullock, KL, G. Malan, and MD Pretorius. "Mammal and bird road mortalities on the Upington to Twee Rivieren main road in the southern Kalahari, South Africa." African Zoology, 2011. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000387.
Full textAbstract:
Road ecology is becoming an increasingly important aspect of conservation biology. Carcasses
lying on the road often confront visitors travelling to the Kgalagadi Transfrontier Park between
Upington and the Twee Rivieren Rest Camp. This study investigated the species killed, the
factors contributing to their deaths, and suggested solutions to curtail these mortalities.
Twelve surveys to record mammal and bird road mortalities were conducted on the R360 main
road between Upington and Twee Rivieren (261 km) from January to September 2007. One
hundred and eighty four carcasses were recorded from 22 species, and the most common taxa
killed were the bat-eared fox (n = 47) and spotted eagle owl (n = 10). The road mortality rate
on the R360 road was very high, 5.44 mammals and 1.14 birds per 100 km. Birds were predominantly
killed in summer. Notably more nocturnal mammals were killed than diurnal and
‘indistinct’ species. A mammal hotspot was identified along the 91 km of road that traversed
the Gordonia duneveld. Since the nine roadside traffic warning signs erected on the R360 road
had no measurable impact on road mortalities, it is recommend that three rumble strip
sections with accompanying signage be erected in the hotspot to slow down vehicles and
curtail mortalities.
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Olivier, Pieter Ignatius. "Patterns of species diversity in coastal forests : case studies on tree and bird assemblages in KwaZulu-Natal, South Africa." Thesis, University of Pretoria, 2014. http://hdl.handle.net/2263/46216.
Full textAbstract:
Habitat loss and fragmentation drives the current extinction crisis. The processes through which it affects biodiversity, however, are complex and poorly understood. This is especially true for spatially complex regions that comprise a mosaic of land-use types, which often range from protected areas to dense human settlements. In such human-modified landscapes, it is important to determine the extent and impact of changing land-use patterns on biodiversity if we are to meet conservation targets or regain ecosystem services. My analyses of coastal forests in KwaZulu-Natal suggest that extensive loss of forests (82%) incurred an extinction debt, modelled to match the 11 bird species now listed as threatened locally. Forest fragments are now also smaller, fewer, further apart and more encroached by human land uses than in the past. Yet, species interactions with the gradient of habitat conditions that now surround forest fragments may have forestalled the realisation of predicted extinctions. I found that natural matrix habitats adjacent forest fragments (e.g. grasslands and woodlands) may facilitate dispersal, enable species spillover from forest fragments, and buffer forest interiors from changes in abiotic conditions associated with high contrast matrix habitats (e.g. agricultural plantations). However, when natural matrix habitats were transformed, these processes were disrupted, which suggest that the effect of landscape change on coastal forest diversity may stretch beyond forest loss per se and the deterministic extinctions predicted by conventional species-area relationships.
Next, I determined that the response of different bird species to habitat fragmentation parameters (i.e. area, connectivity and matrix habitats), depended on life-history traits such as body size, feeding guild and habitat specialization. Extinction risk was, however, not a function of species traits or the fragmentation parameter species responded to. This means that a conservation approach that only focuses on restoring a single fragmentation parameter (e.g. area) may not be successful in halting predicted extinctions, simply because multiple factors may determine extinction risk in coastal forests.
The interpretation of biodiversity patterns in fragmented landscapes may, however, also be influenced by spatial scale. I therefore used a fractal-based sampling design to test how sampling at fine, intermediate and coarse scales influences (1) beta diversity of and (2) inferences from the modelled contribution of niche- versus dispersal-based assembly processes in structuring tree and bird assemblages. I showed that inferences from beta diversity are scale dependent. As a result, studies with similar sampling effort and temporal sampling protocol, but with different sampling grains are likely to report dissimilar ecological patterns, which may ultimately lead to inappropriate conservation strategies.
This thesis provides information of how land-use changes impact on biodiversity patterns and derived processes in a human-modified landscape. It also highlights some conservation opportunities in the coastal forest landscape mosaic, where conservation and restoration actions should focus on both forest fragments and on the surrounding matrices. The conservation of natural matrices may buffer forest communities from impacts associated with high contrast habitat edges, enhance natural plant regeneration through species spillover, provide important linkages between forest fragments, boost regional diversity and allow coastal forests to track environmental change under changing climatic conditions.Thesis (PhD)--University of Pretoria, 2014.
tm2015
Zoology and Entomology
PhD
Unrestricted
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Fredriksson, Felicia. "Analysis of Per- and Polyfluoroalkyl Substances (PFASs) in African Darter (Anhinga rufa) Eggs along Vaal River, South Africa : Comparison of Homologue and Isomer Profiles." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-51772.
Full textAbstract:
Per- and polyfluoroalkyl substances (PFASs) are a group of toxic and persistent organic compounds. Their properties make them extremely resistant and they have been shown to have bioaccumulation and toxic properties in the environment and also to biomagnify in both aquatic and terrestrial food webs. This study has analysed different PFASs in African Darter (Anhinga rufa) eggs from five sites along Vaal River; Orange River, South Africa. Sixteen of 23 analysed PFASs were detected and quantified, and the homologue profiles were studied from all five sites. Total perfluorooctane sulfonic acid (PFOS) (all structural isomers) was the predominated compound of all PFASs, accounting for 88-98% for all sites, with a median concentration range of 58 ng/g ww to 2473 ng/g ww. The second highest concentration was found for perfluorodecanoic acid (PFDA) (1.9-42 ng/g ww), followed by perfluorononanoic acid (PFNA) (1.1-14 ng/g ww) and perfluorohexane sulfonate (PFHxS) (0.68-6.0 ng/g ww). The results showed significantly that the three up-stream sites (Welverdiend, Schoemansdrift and Orkney East) had similar patterns and that eggs from Schoemansdrift had the highest levels of PFASs. This may indicate the same source of origin for these three sites and that Schoemansdrift are closest to the contamination source. The three sites (Welverdiend, Schoemansdrift and Orkney East) with similar pattern is closest to Gauteng, which can be where the emission source is located, because it is an industrial area. Perfluoroalkyl carboxylic acids (PFCAs) and PFOS might originate from different sources and the source for PFCAs could be degradation of fluorotelomer-based precursors. Structural isomer profiles of PFOS showed similar results as the PFAS homologue patterns, which give further indication of the source of origin. The contribution of linear PFOS (L-PFOS) to the total amount of PFOS was between the range of 94 and 97%. Bloemhof had the highest concentration of branched isomers among all sites. The L-PFOS concentrations in Bloemhof were also significantly differ from Schoemansdrift. This indicate two different sources between Bloemhof and the three up-steam sites, or an effect of environmental fractionation.
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Orolowitz, Matthew. "Life on the edge: do body size and drinking dependency influence how birds deal with the heat in South Africa's most extreme desert?" Master's thesis, University of Cape Town, 2020. http://hdl.handle.net/11427/32497.
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Climate change-induced increases in air temperature pose a substantial risk to birds inhabiting arid environments. Terrestrial endotherms, such as birds, can respond to high temperatures by moving to cooler microsites, increasing heat dissipation behaviour and/or suppressing activity. Previous studies have suggested that larger bird species may have a greater suppression of activity (e.g. foraging) than smaller species at high air temperatures. However, this body mass effect may be confounded by drinking behaviour, since different species have diverse drinking ecologies. Using four species of lark that inhabit the Tankwa Karoo National Park, I investigated whether foraging activity and other heat-influenced behaviours were influenced by body mass or drinking behaviour when comparisons were constrained within a single family. These lark species were: Red-capped Lark (24 g), Spikedheeled Lark (25 g), Karoo Lark (29 g) and Large-billed Lark (45 g). There was a two-fold difference in body mass between the lightest (Red-capped Lark) and the heaviest (Large-billed Lark). Moreover, two of these lark species drink surface water (drinking larks; Red-capped and Large-billed Lark) and two do not (non-drinking larks; Spike-heeled and Karoo Lark). I also collected data on other passerines present in the Tankwa Karoo for comparison to the larks. Black bulb thermometers were used to measure the thermal landscape and a combination of instantaneous scan samples and focal observations to record bird behaviour. Black bulb temperatures were as much as 8.16 °C cooler in shaded than in sunny locations. Similarly, black bulb temperatures were as much as 8.02 °C cooler off the ground than on the ground. The results from scan sample data showed limited support that foraging was negatively correlated (although non-significant) with mass between lark species as temperatures increased; however, data from focal observations suggested larks that obtain all water from food had a greater reduction in foraging as temperatures increase than larks that drink free surface water. Within scan samples, heat dissipation and shade-seeking behaviour appeared to be more strongly influenced by whether the species drinks free surface water or not than by differences in body mass. Furthermore, drinking larks dissipate heat at lower temperatures and seek shade at higher temperatures than non-drinking larks. Foraging intensity was higher in the sunny microsites as compared to shaded microsites for all species, suggesting that drinking larks might gain an energetic benefit due to increased heat tolerance. Therefore, non-drinking species may be vulnerable to foraging-thermoregulation trade-offs under climate change. However, ongoing drying trends in the Tankwa Karoo and reduced availability of surface water may make drinking species more vulnerable to climate change in the future than non-drinking species.
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Fraser, Michael 1957. "Effects of natural vegetation, fire and alien plant invasion on bird species assemblages in mountain fynbos of the southwestern Cape Province, South Africa." Master's thesis, University of Cape Town, 1990. http://hdl.handle.net/11427/8423.
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Bibliography: leaves 148-160.The effects on birds of fine-scale differences in plant species assemblage and vegetation structure, and of two major disturbance factors (woody alien plant infestation and fire), were investigated in Mountain Fynbos at two sites in the southwestern Cape Province, South Africa. Three associated processes were also studied. These were the relative importance of three animal taxa as seed predators following fire, the extent to which an indigenous bird species ate alien Acacia cyclops fruits, and potentially dispersed its seeds, and the number of nectarivorous birds which visited an isolated nectar resource. Avian responses to fire in Mountain Fynbos varied according to season, locality and burning regime. Recently and cleanly burnt fynbos at a flat, low altitude, coastal site supported a distinctly non-fynbos avifauna, characterized by relatively large-bodied, ground-feeding, opportunistic species.
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Little, Ian Tchagra. "Bird reproductive success and faunal habitat selection as tools for understanding the impacts of land-use management on moist highland grassland biodiversity in South Africa." Doctoral thesis, University of Cape Town, 2011. http://hdl.handle.net/11427/11407.
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It has been suggested that natural fires in these grasslands would have occurred as infrequently as every four or more years. Currently, the majority of the system is managed by livestock farmers who burn their land annually at the onset of the rainy season (early in the austral summer).
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Ndlovu, Isaac. "An examination of prison, criminality and power in selected contemporary Kenyan and South African narratives." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5159.
Full textAbstract:
Thesis (PhD (English))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: This thesis undertakes a comparative examination of South African and Kenyan auto/biographical narratives of crime and imprisonment. Although some attention is paid to narratives of political imprisonment, the study focuses primarily on autobiographical accounts by criminals, confessional narratives, popular fiction about crime and prison experience, and journalistic accounts of prison life. There is very little critical work at this moment that refers to these forms of prison writing in South Africa and Kenya. Popular prison narratives and to a certain extent the autobiographical in general are characterised by an under-theorised dialecticism. As academic concepts, both the popular and the autobiographical form are characterised by an unstable duality. While the popular has been theorised as being both a field of resistance to power and of consent to its demands, the autobiographical occupies a similar precariously divided position, in this case between fact and fiction, a place where the „I‟ that narrates is simultaneously the subject and object of the narrative. In examining an eclectic body of texts that share the prison as common denominator, my study problematises the tension between self and world, popular and canonical, political and criminal, factual and fictional. In both settings, South Africa and Kenya, the prison as a material and discursive space does not only mirror society but effects shifts and changes in society, and becomes a space of dynamic adaptation and also a locus that disturbs certain hegemonic relations. The way in which the experience of prison opens up to a fundamentally unsettling ambiguity resonates with the ambivalence that characterises both autobiography as genre and the popular as a theoretical concept. My thesis argues that during the entire historical period covered by the narratives that I examine there is a certain excess that attends on the social production of criminality and the practice of imprisonment, both as material realities and as discursive concepts, which allows them to have a haunting effect both on individuals‟ notions of „the self‟ and the constitution of national identities and nationhoods. I argue that the distinction between the colonial and the postcolonial prison is hazy. Therefore a comparative study of Kenyan and South African prison literature helps us understand how modern prisons and notions of criminality in contemporary Africa are intertwined with the broad European colonial project, reflecting larger issues of state power and control over the populace. In relation to South Africa, my study begins with Ruth First‟s 117 Days (1963), and makes a selection of other prisons narratives throughout the apartheid era up to the post-apartheid period which was ushered in by Mandela‟s Long Walk to Freedom (1994). Moving beyond Mandela, I examine other forms of South African crime and prison narratives which have emerged since the publication of Pumla Gobodo-Madikizela‟s A Human Being Died that Night (2003) and Jonny Steinberg‟s The Number (2004). In Kenya, I begin with Ngugi wa Thiongo‟s Detained (1981). I then focus on popular narratives of crime and imprisonment which began with the publication of John Kiriamiti‟s My Life in Crime (1984) up to the first decade of the 21st century, marked yet again by the publication of Kiriamiti‟s My Life in Prison (2004). Besides Kiriamiti‟s two narratives, the other Kenyan texts which I examine are John Kiggia Kimani‟s Life and Times of a Bank Robber (1988) and Prison is not a Holiday Camp (1994), Benjamin Garth Bundeh‟s Birds of Kamiti (1991), and Charles Githae‟s, Comrade Inmate (1994).
AFRIKAANSE OPSOMMING: My proefskrif onderneem ‟n vergelykende studie van Suid-Afrikaanse en Keniaanse auto/biografiese narratiewe van misdaad en gevangeneskap. Hoewel aandag tot ‟n mate geskenk word aan verhale van politieke gevangeneskap, is die primêre fokus van die studie eerder op autobiografiese narratiewe deur misdadigers, konfessionele narratiewe, populêre fiksie met betrekking tot misdaad en gevangenis-ondervindinge, sowel as joernalistieke verslae oor gevangenes se lewens agter tralies. Min kritiese werk is tot dusver in verband met hierdie vorme van gevangenis-narratiewe in Suid-Afrika en Kenia gedoen. Populêre prisoniers-narratiewe, en tot ‟n mate autobiografieë oor die algemeen, word deur ‟n onder-geteoriseerde dialektisisme gekenmerk. As akademiese konsepte word beide die populêre en die autobiografiese vorme deur ‟n onstabiele dualisme gekenmerk. Terwyl die populêre tipe geteoretiseer word as sowel ‟n vorm van weerstand teen mag as van toegee daaraan, word aan die autobiografiese tipe ‟n soortgelyke onstabiele, verdeelde rol toegeskryf – in hierdie geval, tussen feitelikheid en fiksie, ‟n plek waar die “ek” wat vertel terselfdertyd die subjek en objek van die verhaal is. Deur middel van ‟n eklektiese versameling van tekste wat die gevangenis as verwysingspunt deel, problematiseer my verhandeling die spanning tussen self en wêreld, die populêre en die gekanoniseerde, die politieke en die kriminele, die feitelike en die fiktiewe. In beide kontekste, Suid-Afrika en Kenia, weerspieël die gevangenis as diskursiewe spasie nie alleenlik die gemeenskapsomgewing nie, maar veroorsaak dit ook veranderings en verskuiwings in die gemeenskap – sodoende word die gevangenis self ‟n ruimte van dinamiese verandering en ‟n plek wat sekere hegemoniese verhoudings versteur. Die manier waarop die ondervinding van gevangeneskap lei tot ‟n fundamentele versteurende dubbelsinningheid resoneer met die dubbelsinnigheid wat beide die autobiografiese as genre en die populêre as teoretiese konsep karakteriseer. My tesis voer aan dat, gedurende die ganse historiese tydperk wat gedek word deur die narratiewe wat ek hier betrag, daar ‟n sekere oormaat is wat die sosiale produksie van misdaad en die toepassing van gevangesetting begelei, beide as stoflike werklikhede en as diskursiewe konsepte, wat hulle toelaat om ‟n kwellende effek uit te oefen beide of individuele mense se sin van „self‟ en die samestelling van nasionale identiteite en nasionaliteite. Ek voer aan dat die onderskeid tussen die koloniale en die postkoloniale gevangenis onduidelik is, en dat ‟n vergelykende studie van Keniaanse en Suid-Afrikaanse gevangenes-narratiewe ons dus help om te verstaan hoe moderne tronke en idees oor misdaad in Afrika deureengevleg is met die breë Europese koloniale projek, en groter kwessies van staatsmag en beheer oor die bevolking weerspieël. In Suid Afrika begin my studie met Ruth First se 117 Days (1963), en maak dan ‟n seleksie van ander gevangenes-narratiewe van die apartheid-era tot en met die post-apartheid oomblik wat deur Mandela se Long Walk to Freedom ingelui word. Ek vestig dan my aandag op ander vorme van Suid-Afrikaanse misdaad- en gevangenes-narratiewe wat sedert die publikasie van Pumla Gobodo-Madikizela se A Human Being Died that Night (2003) en Jonny Steinberg se The Number (2004) verskyn het. In Kenia begin ek met Ngugi wa Thiongo se Detained (1981), en kyk dan ten slotte na populêre narratiewe van misdaad en gevangeneskap wat hulle aanvang vind met die publikasie van John Kiriamiti se My Life in Crime (1984) tot en met die eerste dekade van die 21ste eeu, nogmaals gemerk deur die publikasie van Kiriamiti se My Life in Prison (2004).