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Game meat production in the Xhariep district of the Free State province : evaluating and optimising resourcesDerbyshire, Walter January 2011 (has links)
Thesis (D. Tech. Environmental health) -- Central University of technology, Free State, 2011 / In 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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A comparison of bird foraging preferences for fruits of indigenous and alien shrubs and seed dispersal potentials in the Cape Floristic RegionMokotjomela, Thabiso Michael 03 1900 (has links)
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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Quantifying crop damage by Grey crowned crane balearica regulorum regulorum and evaluating changes in crane distribution in the North Eastern Cape, South AfricaVan Niekerk, Mark Harry January 2011 (has links)
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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The ichthyofauna and piscivorous avifauna in a small temporarily open/closed Eastern Cape estuary, South AfricaBlake, Justin David January 2010 (has links)
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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How vertebrate communities affect quality and yield of macadamia farms in Levubu, South AfricaLinden, Valerie M. G. 15 May 2019 (has links)
PhD (Zoology) / Department of Zoology / Ecosystem services and disservices are important features in agro-ecosystems and both can have relevant economic impacts on farmers. While there has been much research on the value of ecosystem services, especially that of pest control by bats and birds, ecosystem disservices are often overlooked or estimated separately. Both, services and disservices, however, change with landscape and may be supported by natural vegetation. It is hence inevitable to assess them together to uncover their relative value and importance. Habitat loss and fragmentation are major threats to biodiversity and ecosystem services. Agricultural intensification can cause habitat loss and can negatively affect natural ecosystems and their services. However, the removal of natural vegetation can also reduce ecosystem disservices that origin from natural areas.
This study focused on the economic trade-off between biocontrol by bats and birds and crop raiding by vervet monkeys in South African macadamia orchards, using vertebrate exclusion experiments. Crop quality and yield were assessed and extrapolated to income values. The study furthermore focused in more detail on the impact of orchard edge habitat and farm management on bats as ecosystem service providers as well as the arthropod community, which can provide both services (pollination, biocontrol) as well as disservices (crop damage).
The macadamia industry is highly profitable and plantings are expanding worldwide. South Africa is currently the largest macadamia producer in the world and the study area, Levubu, holds some of the oldest macadamia plantings in the country. The subtropical climate and high annual rainfall make this area an intensively farmed landscape. Levubu lies at the foothills of the Soutpansberg, a centre of biodiversity and patches of natural vegetation wind through orchards of macadamia, avocado, banana and timber. Insect pest pressure is high in the macadamia industry, with several stink bug species (Hemiptera) and two moth species (Lepidoptera) accounting for most of the damage to the crop.
Chapter One provides a detailed overlook over the South African macadamia industry, describes the major pest insect species and their impact on the crop and highlights the role of ecosystem services and disservices and the potential importance of remaining natural areas.
Over three consecutive seasons, between September 2015 and May 2018, bats, birds and monkeys were excluded, using cages with nets, from a total of 96 macadamia trees. Four treatments were applied (Full, Day, Night, Control) to distinguish between effects of the different functional groups. Exclusions took place at orchard edges with natural or human-modified edge habitat to assess the impact of vicinity to natural vegetation on pest control and crop raiding. Results presented in Chapter Two showed that biocontrol by bats and birds was stronger near
natural vegetation and significantly impacted crop quality as well as yield. Effects of bats and birds were still significant at human-modified edges, whereas crop raiding by monkeys is limited to the natural orchard edges. The economic impact analysis shows that the benefits of biocontrol through bats and birds outweighed the income losses due to crop-raiding monkeys. The value of bats and birds was as high as USD 5000 per hectare per year through prevented insect damage and a 60% crop increase. Crop-raiding affected the yield, which dropped by about 26% and resulted in losses of about USD 1500 per hectare. These results highlight the importance of integrating natural areas into agricultural landscapes, even if they incur the risk of being disadvantageous. Farmers need to be made aware of the enormous economic benefits. Effective crop raiding mitigation strategies still need to be researched to avoid negative association with natural areas. These can, however, possibly also limit access for biocntrol agents, like bats and birds and thereby reduce their economic impact. Especially the removal of natural areas or establishment of buffer zones of unpalatable crops between agricultural land and forests is not advisable. Integrative research in agro-ecosystems on trade-offs between a variety of ecosystem services and disservices is necessary in future, rather than assessing them separately.
The bat community on macadamia farms was monitored monthly and compared between orchard edges. Stationary bat detectors were placed at each set of exclosures for two consecutive nights a month, automatically recording from sunset to sunrise. Recorded bat calls were identified manually to species level and activity converted to Miller’s activity index, which counts the number of active minutes per species per night. We analysed the activity per feeding guild over season and landscape setting, estimated species richness and diversity (Hill’s numbers) and species turnover between farms, season and landscape setting, using diversity partitioning. The bat community was mostly influenced by seasonality with season turn-over accounting for 21% of total bat diversity (21.25 species). Edge habitat on the other hand only accounted for 5%. We found higher species richness and activity in the high season compared to the low. While there was no difference in diversity in the high season between the two orchard edge types, species diversity at the human-modified edge was lower than in the natural during the low season. Natural habitat might therefore be more important in the low season, while its effect is overwritten by high food availability during the high season. Clutter-edge species furthermore were more active at the natural orchard edges than open-air feeders, which were in turn more active at human-modified edges. Both activities dropped significantly during the low season.
Chapter Three concludes that the macadamia landscape is able to support a high bat species diversity, which is affected by seasonal differences, probably due to food availability. Natural areas are important to be maintained to support sensitive species, relying on clutter habitat and natural roosts.
Habitat features as well as farm management can also influence arthropod communities. Visual observations took place each month for 20 minutes per tree. Observations were counted and identified to at least order level. Chapter Four concentrates on the impact of orchard edge habitat and insecticide treatment on honey bees (83% of Hymenoptera observations) abundance. Honey bees were the only taxon significantly responding to both variables, with higher abundance close to natural areas and increasing abundance with increasing time since pesticide application. Honey bees furthermore seemed to recover slightly quicker from population crashes after insecticide treatments at natural edges than they did at human-modified edges. Hymenoptera can be highly beneficial to macadamia farmers, as farmers are heavily relying on pollination by honey bees and parasitoids are known to feed on major macadamia pest insect species. These ecosystem service providers were mostly affected by habitat and management practices, which may compromise their ecosystem service provision. Although commercial bee hives are exposed throughout macadamia orchards, they do not appear to fully replace the pollination and biocontrol services provided by feral species, which can be enhanced through resource supplementation by patches of nearby natural vegetation.
Chapter Five concludes with emphasizing the general importance of natural vegetation in landscape planning of agricultural areas. This study proved confidently that benefits through ecosystem services largely outweigh negative impacts of ecosystem disservices, both stemming from these natural areas. Through the inclusion, maintenance and restoration of such patches of natural vegetation, farmers can potentially increase the value and effectiveness of biocontrol by bats and birds or other services. Seasonality largely determined bat species diversity, and a general high species diversity was observed in the macadamia landscape, possibly due to a certain degree of landscape heterogeneity and high food availability. Activity patterns of clutter-edge and open-air feeding bats varied with edge habitat, while clutter-dependent bat species / NRF
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