Masters Degrees (Ecology)

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

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Aardvark and people: can a shy species be widely known in a localised area?
(2022) Makwati, Nolutho.; Kraai, Manqhai.; Tsvuura, Zivanai.
The increase in human populations has led to humans sharing space with wild animals even in the natural habitats of the animals. Conflicts may arise when people and wildlife attempt to fulfill their needs which can be detrimental to one or both parties, and this type of conflict is called human-wildlife conflict (HWC). The human needs include people hunting wild animals for consumption of the animal and trading in animal body parts.Hunting is one of the factors that decreases populations of numerous animal species, and it occurs in many parts of the world e.g. in Africa, Asia and South America, where it contributes to extinction of species. The conservation and management of burrowing animals is a major challenge due to their elusive and nocturnal behaviour. The aardvark is an African medium-sized, burrowing mammal whose conservation status has not been updated recently due to the difficulties associated with studying nocturnal animals. Aardvarks may play a significant ecological role in the ecosystems in which they occur, such as by changing the landscape through their digging activities, or through affecting the dispersal of seeds. Therefore, the aim of this study was to explore the influence of humans on population trends and activity patterns of aardvarks outside protected areas, and to determine people’s perceptions about the animal. The study was conducted in Ncunjane village in Msinga Local Municipality, KwaZulu-Natal Province of South Africa. To understand people’s perceptions about aardvark in their community, I used a semistructured questionnaire survey. I asked personal information of the participants (sex, level of education and age), and questions related to people’s perceptions about the aardvark, such as people’s knowledge, myths, and their uses of the animal or its body parts. To determine activity patterns of the animal, I focused on aardvark foraging activities in a semi- arid savanna ecosystem that is also used as a communal rangeland over eight months between 2020 and 2021. I measured and quantified aardvark foraging holes using 53 50 m × 10 m transects where there was evidence of aardvark activity. In addition, I quantified aardvark burrowing of dens in the dry, wet and early dry seasons using walking transects guided by a research assistant who knows the area. I found that people have different perspectives about aardvark with the majority (78%) of respondents having strongly positive perceptions. The positive perceptions arise from aardvark not causing physical harm to people, and fleeing away upon sighting people. I found that aardvarks were mainly hunted for meat while some animal body parts were sold to traditional healers for traditional medicine. All seasons consisted of a greater number (> 51%) of old than new and very old foraging holes.The surface area of new, old, very old holes differed significantly with season (P < 0.0001) and the depth of new, old and very old holes also varied with season (P < 0.0001). In addition, the contents of foraging holes varied with age of the hole and season in that new holes lacked evidence of plant life across seasons. Aardvark dens were used by other animals such as spiders, wild cats, Cape porcupines and snakes. Hence, an increase in aardvark holes can be associated with significant landscape heterogeneity for vegetation and animal life. Aardvarks in Ncunjane fed close to their dens presumablyto mitigate against human predation through hunting threats, which may directly affect the extent of aardvark digging activities. These results show that aardvarks may be categorised as ecosystem engineers as the burrows provide shelter for other animals, also, their effects on other animals are disproportionate to their abundance. These results highlight that aardvarks are threatened by human uses and may decline in abundance in the area. Finally, aardvarks remain poorly studied in landscapes shared with humans. Further studies to assess aardvark numbers in human-dominated landscapes are required which can raise awareness and play a significant role in conservation of aardvarks.
Ant community responses to fertiliser application and disturbance in a mistbelt grassland, KwaZulu-Natal.
(2021) Khoza, Lindiwe Rebecca.; Munyai, Thinandavha Caswell.; Andersen, Alan N.
Abstract available in PDF.
Aspects of fruit digestion and selection in selected Southern African avain frugivores.
(2014) Zungu, Manqoba Moses.; Downs, Colleen Thelma.
Fruit-frugivore interactions play a central in maintaining the structure and diversity of ecosystems through their effects on seed dispersal. Because fruit selection and thus fruit removal represents the first stage in the seed dispersal process, understanding factors affecting fruit selection can play an important role in the formulation of sound conservation efforts especially light of the on-going habitat change. However, to date, the research is inconclusive as to factors affecting fruit selection as results have revealed inconsistent and controversial with a huge variation in fruit selection patterns between species and within individuals of the same species. The huge inter- and intra-specific variation in fruit selection patterns precludes any generalizations on fruit selection notwithstanding the research effort addressing the issue. One factor that could be attributed to this pattern is that most studies on fruit selection patterns in frugivorous birds have studied fruit attributes or physiological adaptations of frugivores to fruits in isolation. Because fruit profitability is affected by both pre- and post-ingestional factors, studying these factors in isolation deprives us of fresh insights into the fruit-frugivore interaction. Therefore by relating the physiological aspects of frugivores to fruit characteristics, this study aims to provide a link between the physiology of birds and their feeding ecology. Cape white-eyes (Zosterops virens), red-winged starlings (Onychognathus morio) and speckled mousebirds (Colius striatus) were used for this study. In the first part of this thesis, transit times and digestive efficiencies of birds fed equicaloric glucose and sucrose artificial fruit diets of varying concentrations were determined. Three concentrations were used: low (6.6%), medium (12.4%) and high (22%). Digesta transit times of birds increased with an increase in concentration for all diets but were generally higher on glucose diets. This finding has been widely reported in other similar studies. The increase in digesta transit times with an increase in sugar concentration may be due to high nutrient density on high concentration diets which require a longer processing time. Intake rates, on the other hand, decreased with an increase in sugar concentration. The inverse relationship between food intake and nutrient levels has often been attributed to compensatory feeding which posits that birds respond to nutrient dilution by increasing intake to allow a constant flux of assimilated energy. Indeed, speckled mousebirds and Cape white-eyes maintained a constant assimilated energy intake on sucrose diets by modulating food intake rates. The apparent assimilation efficiencies of glucose diets for all species were comparable and typical of those found in other frugivorous birds. However, red-winged starlings displayed low assimilation efficiencies for sucrose diets and lost significant body mass on all sucrose diets. The lack of significant sucrase activity in this species was attributed to this finding. This study showed the importance of digestive physiology in explaining fruit selection patterns in frugivorous birds. The second part of this thesis assessed the deterrence effects of tannins which are ubiquitous secondary compounds in plant material and are known for their ability to bind to protein which reduces nitrogen availability in the diet. In this study, birds were fed artificial fruit diets containing varying levels of tannins (0%, 2.5% and 5%) in paired choice tests. It was predicted that tannins would have no effect at low concentrations but at higher concentrations would act as deterrents although the levels at which they would become deterrents would differ among species. Red-winged starlings preferred the control diet, were indifferent to the medium tannin diet and were deterred by the high tannin diet whereas speckled mousebirds and Cape white-eyes were not deterred at all concentrations. The discrepancy in the results was attributed to differences in taste sensitivity, tolerance levels and detoxification mechanisms of secondary compounds between species. Occasional geophagy and consuming a broad diet were also implicated in producing the results obtained. Plant secondary compounds in fruits are diverse and their effects are similarly diverse and there is a possibility that different groups of secondary compounds generate disparate effects. Similar studies on other types of secondary compounds may thus contribute towards a broader understanding of the role of secondary compounds in mediating fruit-frugivore interactions. Overall, this study showed how diet affects ability to handle secondary compounds in fruits. The third part of this thesis addressed the influence of ethanol concentration on fruit selection in frugivorous birds. Because ethanol is ubiquitous in fruits and its concentration is positively correlated to fruit sugars, it has been suggested that because frugivores could use its odour to locate fruiting plants, they should select fruit with high ethanol concentrations. The aim of this study was to test this hypothesis by determining whether frugivorous birds show a preference for fruit laden with alcohol at levels equivalent to those of over-ripe fruits. Birds were provided with two artificial fruit diets in pairwise choice tests: an experimental diet containing 1% ethanol and an artificial fruit diet with no ethanol. For all species, there were no significant differences in the amount of fruit consumed between the two food types. These findings provided corroborating evidence to the suggestion that birds are unlikely to prefer over-ripe fruits compared to ripe fruits due to the negative impacts associated with ingesting ethanol at high concentrations. However, it could be possible that the lack of preference observed in this study was because the ethanol concentrations used were too low to be detected. Overall, this study suggests that at high concentrations, ethanol in fruits acts as a deterrent rather than an attractant. The last part of this thesis was conducted to determine the use of taste and olfaction by red-winged starlings in making foraging decisions. To determine whether they use taste in fruit selection, they were concurrently offered a control artificial fruit diet with another artificial fruit diet flavoured with different concentrations of ethanol and various fruit essences. To test whether they were able to use olfaction to locate food, they were provided with two choices: artificial fruit suspended over either banana and orange fruit essences and ethanol of varying concentrations or a control artificial fruit (without essence). It was hypothesized that (1) red-winged starlings have tasting ability which helps them in selecting fruits to feed on and that (2) red-winged starlings use olfaction to locate food. Results were consistent with the first hypothesis but inconsistent with the second one. Thus, red-winged starlings use taste when selecting fruits to feed on but do not use olfaction to locate fruit sources. The latter was unexpected because birds with olfactory bulb sizes similar to theirs exhibit advanced olfactory abilities. It was speculated that the lack of olfactory abilities in starlings could be attributed to the fact that this study was conducted outside of this species’ breeding season when olfactory abilities were likely to be lowest and also to that olfactory abilities may not have been important at the scale investigated in this study. Overall, the study showed that the sense of taste in birds plays an important role in making foraging decisions than currently appreciated. Overall, this thesis demonstrated the value of relating physiological attributes of frugivores to fruit attributes in acquiring deeper understanding of fruit-frugivore interactions. One particular advantage of the methodology employed in this study was that it controlled for covariance among fruit characters and also removed the confounding effects of as seed size and secondary compound composition. The shortcoming of this approach is related to the applicability of the results to the field conditions. Therefore an approach combining laboratory and field observations may produce results that may be important in informing us about how to manage our ecosystems.
Aspects of Nile crocodile (Crocodylus niloticus) population ecology and behaviour in Pongolapoort Dam, KwaZulu-Natal.
(2015) Summers, Mark Kai.; Downs, Colleen Thelma.
Pongolapoort Dam is one of the largest dams in South Africa by volume. It is also home to a breeding population of Nile crocodiles (Crocodylus niloticus). Crocodiles are keystone species which play an important ecological role in their aquatic habitats but are under threat globally. Consequently the aims of this project were to investigate the population number, nesting ecology, and behavioural aspects of gaping in Nile crocodiles at Pongolapoort Dam. Data were captured from July 2014 to August 2015, where there was a marked decrease in water levels in Pongolapoort Dam due to a drought occurring throughout KwaZulu-Natal. An estimated 549 Nile crocodiles occurred in Pongolapoort Dam in 2015, an increase in population from a conservative estimate of 273 individuals in 2010. The majority (80%) of the Nile crocodile population occurred in the inlet section of the dam, and with dropping water levels, the crocodiles congregated in large numbers in the Croc Bay region of the inlet. The population structure changed from 2010 when the majority occurred in the juvenile class to the majority of the crocodiles occurring in the sub-adult and adult size class in 2014/2015. The reproductive output of a population can be an indicator of population health. Consequently nesting ecology of Nile crocodiles was investigated at Pongolapoort Dam for the 2014/2015 nesting season. A total of 38 Nile crocodile nests were found over four nesting sites in the river section of Pongolapoort Dam. Nest effort decreased from 73% in 2009/2010 to 43% in 2014/2015, with a density of 4.9 nests per kilometre in the river section. All nests were found in alluvial deposits where Phragmites australis was the dominant vegetation. Some nests were predated by water monitors (Varanus niloticus); however, two nurseries were found containing hatchlings, while many nests showed signs of being dug up by the nesting females. The N2 Bend and Buffalo Bend floodplain were the most important nesting grounds, and this was attributed to the presence of suitable nesting conditions. Gaping behaviour in Nile crocodiles has received little attention as there are conflicting ideas as to why gaping occurs. The majority of literature suggests that gaping is a thermoregulatory response aimed at cooling the head of the crocodile. We aimed to identify other possible behaviours associated with gaping, at a basking bank in Pongolapoort Dam during winter. Preliminary results suggest that gaping may be a communicative or behavioural posture brought on by the following factors; position of the crocodile relative to the water, total length of the crocodile, time of gape, degree of gape, nearest neighbouring crocodile and number of neighbouring crocodiles. Further research is needed to help understand this behaviour of Nile crocodiles and its importance in their ecology and behaviour. The study showed that the population of Nile crocodiles in Pongolapoort Dam is increasing and remains in a healthy state compared with other population in South Africa. Insights into their behaviour may be applicable to other crocodilian taxa.
Aspects of the ecology of Cape porcupines on farmlands, peri-urban and suburban areas in KwaZulu-Natal, South Africa.
(2018) Ngcobo, Samukelisiwe Princess.; Downs, Colleen Thelma.; Wilson, Amy-Leigh.
The unprecedented changes in the environmental and ecological processes of the biosphere have led some to believe that we have transitioned into a new geological era from the Holocene. This current era is known as the Anthropocene epoch, termed as such due to the unprecedented human-induced environmental change. Humans have dominated global changes in the environment and climate through the conversion of natural land-use systems into anthropogenic landscapes dominated by agriculture, urban and industrial development. The conversion and destruction of natural habitats into anthropogenic ones have caused shifts in ecosystem functions, and ultimately this has dire consequences for biological diversity globally. Although many species have gone extinct due to anthropogenic land-use changes, some have persisted and thrive within human-dominated landscapes. These species have adapted well to these landscapes, to the point whereby they have modified their behaviour to exploit anthropogenic resources, and increase in numbers. However, the expansion of human land-use into historically wildlands means that wildlife and humans will increasingly interact with one another. This is cause for concern, particularly with the projection of future anthropogenic land-use expansion and intensification. As a result, there is need to research how wildlife in human-dominated landscapes adapt and how their survival will influence human-wildlife interaction in the future. Cape porcupines, Hystrix africaeaustralis, are one of those species which have benefited from anthropogenic change of the landscape. However, due to their effectiveness in exploiting anthropogenic food and shelter resources, they have been perceived as problematic. This has led to their persecutions in certain areas, particularly within agricultural systems. But they are also becoming increasingly problematic also in suburbia. Therefore, as motivation for this study, we aim to investigate the spatial ecology of Cape porcupines in human-dominated landscapes of farmland and urban areas. This is because there is very little information on their space use and the research on Cape porcupines is outdated. Consequently, due to their potential to become conflict-causing, there is urgency to determine their spatial ecology and contribute knowledge towards their conservation and management in these landscapes. Therefore, Cape porcupine home range and habitat use along a land-use gradient were investigated. A total of fifteen individual Cape porcupines were captured and fitted with Global Positioning System (GPS) collar transmitters in farmlands of Fort Nottingham, a peri-urban estate near Howick, and in a suburban estate in Ballito, in KwaZulu-Natal, South Africa. Data obtained from the GPS transmitters were used to estimate Cape porcupine home ranges using the Kernel Density Estimator (KDE) (Chapter 2). Overall estimated Cape porcupine home ranges were very small (n = 9, mean ± SE: 39.37 ± 6.33 ha) compared with other Hystrix porcupines. Farmland Cape porcupine home ranges (24.57 ha) were the smallest relative to the peri-urban (34.61 ha) and suburban areas (45.18 ha). These results were as expected, since it has been revealed that porcupine home ranges are determined by forage availability. Consequently, these human-dominated habitats have anthropogenic food resources that are constant relative to natural resources. This means that the expansion of human-dominated landscapes will result in the contraction of Cape porcupine home ranges as they benefit from anthropogenic resources. With the aid of the radio-telemetry data, we also determined Cape porcupine habitat use in the farmland, peri-urban and suburban areas, in KwaZulu-Natal, South Africa (Chapter 3). Habitat use of Cape porcupines were investigated at the landscape-scale (2nd order of selection) and the home range-scale (3rd order of selection). Habitat use of Cape porcupines varied at the two-levels of selection, and individual Cape porcupines utilized different habitats, but generally selected the forest with bushland habitat above other habitats. We thought Cape porcupine habitat use would be determined by habitats dominated by anthropogenic food resources (crops and gardens). However, Cape porcupines utilized natural food resources although they lived in human-dominated landscapes. Their habitat use was determined by the presence of forest with bushland habitat, and to a less extent by croplands or residential gardens. This means that at this point, Cape porcupines opportunistically utilized anthropogenic food resources according to their availability. However, these results should be interpreted with caution since the study duration was limited by battery life of the GPS transmitters (~ 5 months). This study revealed that Cape porcupine showed individual variation in ranging patterns and habitat use which were likely influenced by forage availability. In addition, Cape porcupines shifted their spatial behaviour depending on the landscape they inhabited. Therefore, the behavioural flexibility of Cape porcupines enabled them to adapt to anthropogenic changing land-use and successfully persist there.
Aspects of the ecology of feral cats (Felis catus) in urban Pietermaritzburg, KwaZulu-Natal, South Africa.
(2015) Pillay, Kerushka Robyn.; Downs, Colleen Thelma.
With changing land use such as urbanization, certain species thrive and are successful despite changes in the modified landscapes. Therefore, study of the ecology, adaptations and survival of these species in an urban context is warranted. Often these species include alien invasive species. An example is the feral cat (Felis catus). The negative effects caused by feral cats generally include impacts on native species of wildlife because of their highly predatory nature and their ability to spread zoonotic diseases. Furthermore, it often becomes a public nuisance occurring at high densities in urban areas. Consequently the aspects of the ecology of feral cats were studied from March 2014 to June 2015 in an urban mosaic in Pietermaritzburg, KwaZulu-Natal, South Africa. The research was also undertaken to propose and assist with an effective management strategy that was deemed necessary to control high densities of feral cats existing in urban Pietermaritzburg. Feral cats were trapped and fitted with GPS-GSM-UHF tracking collars in order to determine their home and core range sizes within the urban mosaic containing varying degrees of green and urban areas. Additionally, the disease prevalence in feral cats was also documented by collecting blood samples from feral cats occurring in many areas of the greater Pietermaritzburg area. The information gained in this study allowed compilation of feral cat management recommendations and strategies in order to control the increasing feral cat communities already established in Pietermaritzburg. Feral cat telemetry data showed that availability and abundance of food resources were the primary influencing factors affecting feral cat home range size and distribution as core areas contained at least one supplemental feeding site. There was considerable overlap of feral cats within the core areas. Overall home range size of feral cats was small but varied with individual cats. There was considerable overlap between and within the sexes. There were no significant differences in range size between sexes nor between day and night. However, diurnal ranges were generally smaller than nocturnal range sizes. Generally male feral cats had larger home ranges than female feral cats and nocturnal activity was higher across genders. Feral cats used urban areas more than green areas suggesting that the urban environment supports larger numbers of feral cats. The disease prevalence in feral cats tested was generally low. However, some tested positive for Feline Leukaemia Virus (FeLV) (28.6%) and for Feline Immunodeficiency Virus (FIV) (7.1 %). There was no occurrence of Feline Corona Viruses (FCoV) in feral cats tested in Pietermaritzburg. The location of feral cats within the city had a significant effect on prevalence of FeLV infection in feral cats tested. The findings of this study of feral cats in the urban mosaic of Pietermaritzburg showed that feral cats’ habitat use and home range were mainly affected by supplemental food resources. Furthermore, disease prevalence in feral cats tested was generally low. Thus efficient, cost-effective and realistic methods need to be implemented to control high densities of feral cats in this urban area require the use of a low-key supplemental feeding programme with a combined sterilization programme. This proposed strategy should be adopted and sustained with involvement of all concerned stakeholders to ensure that the welfare and population of the cats is well managed and humanely controlled particularly as this is an alien, invasive species. Additionally, all cats that test positive for any disease should be removed from the population to stop the spread of diseases to other feral or domestic cats in urban areas of Pietermaritzburg.
Aspects of the urban ecology of the Spotted Thick-knee (Burhinus capensis)
(2021) Josiah, Kyrone Kent.; Downs, Colleen Thelma.
Abstract available in PDF.
Assessing the success of red-billed oxpecker translocations as a conservation tool in KwaZulu-Natal, South Africa.
(2016) Jordaan, Maryna.; Downs, Colleen Thelma.; Combrink, Leigh.
There are numerous factors that contribute to a bird species becoming threatened and in need of increased conservation efforts in order to survive. Compared with fossil records, current extinction rates are much higher than expected, which emphasizes the need for conservation. Conservation translocations aim to increase the survival of threatened species by ameliorating their possibility of extinction, and contribute either to educational, scientific or supportive purposes in this. Reintroductions or translocations are a well-established method for increasing a species’ distribution and for restoring their historical range. Translocations are defined as human-mediated movements of organisms from one area and released in another. A translocation is only considered successful when a population is self-sustained through breeding of the released individuals and does not require intervention. Oxpeckers are African passerines from the starling lineage. Historically, red-billed oxpeckers (Buphagus erythrorhynchus) had a distributional range that extended from Eritrea to Somalia, through south-eastern Sudan to Zimbabwe and into the former Transvaal, Natal and Eastern Cape Provinces, South Africa. Oxpecker populations became threatened in South Africa in the early years of the 20th century. In southern Africa, red-billed oxpeckers became Near-Threatened as a result of cattle dips with substances toxic to the birds, and because of a significant decrease in their large game host species. Conservation efforts in the 1980s onwards have attempted to deal with the factors causing their demise. In 2002, The Endangered Wildlife Trust began translocating red-billed oxpeckers to areas where they had gone locally extinct, in an attempt to increase their current distribution and population in South Africa. Consequently, we documented and reviewed the various capture and quarantine methods, conducted since 1988 to the present, in the various translocations of red-billed oxpeckers. We also highlighted lessons learnt from these translocation events. To determine how successful these translocations were, we compared changes in the Southern African Bird Atlas Project (SABAP) reporting rate data and determined the presence or absence of red-billed oxpeckers at all the 24 translocation release sites in KwaZulu-Natal (KZN). In SABAP 1, data on species occurrences were collected at the Quarter Degree Grid Cell (QDGC) level. In SABAP 2, this was refined to pentads, where nine pentads are in one QDGC. Therefore, the reporting rate comparison was done at QDGC level. Prior to these translocations, red-billed oxpeckers were absent from all these sites. Specifically, we conducted transect surveys to determine red-billed oxpecker’s population estimates in Ithala Game Reserve (IGR) and Tembe Elephant Park (TEP). We also netted and ringed red-billed oxpeckers at these sites to obtain morphological and genetic data and to determine their breeding status. Furthermore, we distributed an online questionnaire to determine public perceptions on red-billed oxpecker’s range expansion in South Africa. We analysed the SABAP data using general linear modelling and the survey data using the Distance Programme in R Studio. There was a significant increase in reporting rates of red-billed oxpeckers in southern Africa since the end of SABAP1 in 1991 with several new areas where they had established. This was again confirmed from landowners reporting the first observation made of red-billed oxpeckers on their respective properties. Reporting rates at the specific translocated release sites had also increased. Twenty-four per cent of the QDGCs (n = 170) showed an increase in reporting rates in southern Africa, however, 36% of the QDGCs showed a decrease in reporting rates (n = 258). Fourteen per cent of the QDGCs (n = 100) showed new areas colonized by red-billed oxpeckers. In South Africa, red-billed oxpeckers had colonised several new areas, particularly near areas where reporting rates had increased. Twenty-six per cent of the QDGCs showed areas where red- billed oxpeckers were absent and had gone locally extinct (n = 187); however these areas were mostly in Botswana and Zimbabwe. We determined that habitat, host preference and host herd size were important factors when calculating population densities of red-billed oxpeckers. Detection probabilities for red-billed oxpeckers were highest in open bush habitat and where large herds were present. In IGR, red-billed oxpeckers were seen in 8% (n = 33) of the total of 391 observations made. In TEP, red-billed oxpeckers were observed in 6% (n = 24) of the total 378 observations made. In both IGR and TEP all red-billed oxpeckers we trapped and ringed had not been previously ringed and some had brood patches supporting their successful reproduction there. To date, a total of 24 reintroduction events and 13 population reinforcements have taken place, with a total of 1359 red-billed oxpeckers translocated in South Africa. The increase in reports of red-billed oxpecker sightings, especially at release sites and on nearby land, showed the importance of translocations for the conservation of oxpeckers. In addition, the placement of artificial nest boxes has increased the likelihood of red-billed oxpeckers breeding at their new translocated site. The recent down-grading of red-billed oxpeckers from Near Threatened to Least Concern, and the data collected in our study support the success of translocation as a conservation tool for this species. Translocations of red-billed oxpeckers in South Africa should be considered one of the more successful of such programmes as indicated by its success.
Assessing the trade of reptile species in the South African pet trade.
(2021) Mantintsilili, Asekho.; Downs, Colleen Thelma.; Shivambu, Tinyiko Cavin.; Shivambu, Ndivhuwo.
Despite the negative impacts that the pet trade has on the native and non-native biodiversity, economy and human health, the research suggests that the demand for pets and the extent of trade in live animals as pets has increased dramatically over the years. As a result, many species, including reptiles, have been translocated and introduced into new or non-native environments. Some of these have established feral populations, become invasive and are causing significant environmental and socio-economic impacts on non-native environments. Reptiles are among the most popular groups of animals in the pet trade industry globally. Trade in pet reptiles in South Africa is large and one of the major pathways through which non-native species, including invasive species, are introduced into the country. Despite this, little is known about the dynamics of the wildlife trade in pet reptiles globally. To understand the dynamics of the global trade in pet reptiles, we carried out a comprehensive literature search to gather relevant information from reptile pet trade-based publications. We further compiled a list of traded pet reptiles from all South African physical pet stores and online advertising websites to determine which species are traded, pose an invasion risk and have potential environmental and socio-economic impacts. We found a total of 39 publications based on the reptile pet trade from 1994 – 2021 worldwide. Our analyses revealed that the research effort was not uniform globally, with the majority (63.6%) of all relevant studies originating from three continents (Asia, Europe, and North America). Moreover, the United States of America (North America) and Indonesia (Asia) produced the greatest research outputs (12.1% each) compared with other countries across the world. We found at least 1140 reptile species belonging to 60 families involved in the global pet trade, with invasive red-eared slider Trachemys scripta elegans being the most frequently studied species (number of studies = 23/39). Of the recorded species, at least 79 are invasive, 46 endangered, 29 critically endangered, while only 546 are CITES-listed. In terms of reptile species sold in South Africa, we recorded a total of 2771 individuals representing 88 unique reptiles, 69 from physical pet stores and 18 from online advertising websites. KwaZulu-Natal, Gauteng and Western Cape Provinces had the highest number of pet stores and online advertising websites; therefore, they subsequently recorded the highest number of pet reptiles compared with other provinces. Physical pet stores were found to have the highest number of species compared to online trade. Of the recorded species, 76 are nonnative, and 15 of these are invasive to South Africa. Moreover, only 32 pet reptiles are listed under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). For current distributions, red-eared slider Trachemys scripta elegans, P. guttatus, and Western diamondback rattlesnake Crotalus atrox had the largest predicted climatic suitability. The future predictions for the latter two species were predicted to increase, while red-eared slider suitability shifted. Some species, such as Burmese pythons Python bivittatus, showed low invasion risk based on climatic suitability. However, given their large body size, history of invasion and their popularity in the pet trade, they are most likely to escape or be released from captivity and become invasive. A total of 76 reptile species were assessed for environmental and socio-economic impacts using the Generic Impact Scoring System (GISS), Environmental Impact Classification for Alien Taxa (EICAT), and Socio-Economic Impact Classification for Alien Taxa (SEICAT). Using GISS, we found that 13 species had environmental impacts (E_GISS), while 11 species had socio-economic impacts (SE_GISS). For EICAT and SEICAT, 13 species had environmental impacts, and eight had socio-economic impacts, respectively. The most popular pet species, red-tailed boa Boa constrictor, green iguana Iguana iguana, P. bivittatus, T. elegans, and central bearded dragon Pogona vitticeps had impacts in all the three scoring schemes. The later species and corn snake (Pantherophis guttatus) scored the highest for all impact schemes. Species sold in high numbers, with large climatically suitability and potential impacts, are more likely to establish feral populations and become invasive should they escape or be released from captivity. We, therefore, recommended that the trade in pet reptiles should be constantly monitored to avoid new introductions and the implications that the pet trade may have to the country.
Assessment of spatial and temporal variation in water quality of the Pienaars River, Limpopo water management area.
(2018) Mlotshwa, Lungile Wendy.; Tsvuura, Zivanai.; Ndhlala, Ashwell Rungano.; Ncube, Bhekumthetho.
Abstract available in pdf.
Assessment of the current ecological integrity of the uMngeni River, KwaZulu-Natal, South Africa, using fish community structures and attributes of the Labeobarbus natalensis (Castelnau, 1861) populations.
(2019) Dlamini, Pumla Vanessa.; Downs, Colleen Thelma.; O'Brien, Gordon Craig.
Rivers are the main source of freshwater water for human communities and provide people with numerous ecosystem services such as water purification, transportation, power generation, food supply, and water for domestic, agricultural and industrial use. Water resources, and the ecosystem services they provide, are particularly important in developing countries, such as South Africa. The uMngeni River, is a strategic resource that provides water to two of the largest cities in KwaZulu-Natal Province (the uMgungundlovu and eThekwini municipalities), with more than four million people, making it socio-economically important. As such, to maintain sustainability the protection of the river is important. However, in South Africa and KwaZulu-Natal, the impact of anthropogenic activities has made riverine ecosystems one of the most threatened types of ecosystems in the world. The use of fish as key indicators of the ecological state of aquatic ecosystems is well established as their vulnerability to environmental change, mobility, longevity and relative ease of species identification make them good indicators. This study evaluated the current ecological integrity of the uMngeni River in KwaZulu-Natal using multiple lines of evidence including fish communities and the state of Labeobarbus natalensis (the KwaZulu-Natal yellowfish) populations, and environmental variables. The research was undertaken in the major man-made lakes (dams) in the uMngeni River (namely Midmar, Albert Falls, Nagle and Inanda Dams) and in the rivers of the uMngeni Catchment. Abiotic lines of evidence investigated included water quality and habitat, while the biotic lines of evidence included fish community structures and attributes of the population of L. natalensis. Fish community structures at eight selected River Eco-status Monitoring Programme (REMP) sites in the uMngeni catchment were considered. This included consideration of how the fish communities responded to changes in a range of environmental variables and alien fishes using the Fish Response Assessment Index (FRAI), we were able to determine that the ecological integrity of the uMngeni River decreases in a downstream gradient from the upper reaches of the catchment to lower reaches, due the synergistic effect of multiple anthropogenic stressors. The multivariate analyses indicated that the anthropogenic impacts responsible for shifts in fish community structures, and the associated ecological integrity of the river were related to changes in instream habitats and water quality stressors primarily. Most of the environmental changes identified can be linked to flow modifications and land use activities throughout the uMngeni catchment. Assessments of attributes of the L. natalensis populations from large instream impoundments in the uMngeni River (namely Midmar, Albert Falls, Nagle and Inanda Dam) resulted in diminishing wellbeing of the populations of this endemic migratory fish progressively both in abundance and structure, down the length of the catchment. The quality and quantity of water diminished down the catchment gradient with this gradient and the effect of the barriers themselves can partially be attributed to the impaired state of the populations. Impoundments are not preferred by juvenile and young L. natalensis that prefer shallow riffle habitats that are lacking in dams, the occurrence of many predatory alien fishes in the dam can also be attributed to the absence of small yellowfish in the dams. The outcomes of this study can contribute to the sustainable management and development of conservation plans for the rivers and dams in the uMngeni catchment. Major stressors that should be mitigated include the barrier effect and operation or flow releases from the large dams and smaller weirs etc. that cause river fragmentation in the catchment. It is recommended that management plans for the conservation of the fishes in the catchment should be developed which is achievable as the current supply of resources in the catchment is balanced with the demand for use. Fish passages should be established in all of the dams in the uMngeni River to allow migratory fish free passage along the river and to re-establish river connectivity processes. Additionally, the removal of redundant weirs or partial man-made barriers is recommended to alleviate the effects of fragmentation particularly on the yellowfish in the catchment. More research is required to understand the migratory requirements of fishes in the catchments and the cost-benefit of mitigating river fragmentation to achieve a sustainable balance between the use and protection of resources in the catchment. Finally, the study has identified water quality and flow stressors that are negatively affecting the wellbeing of the fish communities in the catchment. The water quality stressors derived from land-based activities and associated management of flows in the catchment must be improved to attain a sustainable balance between the use and protection of the resources of the uMngeni Catchment.
Behaviour of bottlenose dolphins : inference for dolphin tourism off Durban, South Africa.
(2008) Mahomed, Maleeha.
During long-term studies of dolphins, the number of individuals in the population being studied are constantly monitored using the technique of photo-identification. This constant monitoring makes use of different researchers over time. Therefore, measurement of photographic quality and individual distinctiveness for photo-identification analyses was incorporated in this dissertation to provide an additional data set for analysis. Researchers with differing levels of experiences did not obtain the same information from the same photograph and were unable to reliably quantify variables of photo quality and individual distinctiveness, but experienced researchers were found to be more adept than inexperienced researchers in counting notches on the dorsal fin of bottlenose dolphins. These results highlight the necessity for researchers to be trained in photo-identification techniques prior to carrying out their study. This study theodolite tracked dolphins off Durban from June 2004 to Feb 2005 to assess habitat utilization of bottlenose dolphins (Tursiops aduncus) in the Durban bay region. Dolphins were seen in all months surveyed and throughout the survey area. Temporal distribution of dolphins was skewed with 91% of dolphins seen before midday and 98% of sightings observed in water depths less than 30m. Six behavioural categories were recorded, including: social, fast travel, slow travel, feeding, resting and milling. The most dominant behaviour exhibited by dolphins was slow travel (46%) followed by feeding (27%). Resting was not observed at all. Of the feeding behaviour 88% occurred in the southern end of the bay whereas other behaviours occurred randomly throughout the survey area. Additional theodolite tracks were conducted during experimental boat approaches (before, during and after boat approaches) to determine potential short-term reactions of dolphins to dolphin watching boats. Two speeds of approach (slow ~ < 5 km/hr and fast ~ > 40 km/hr) and two distances of approach (20m and 80 m) were tested. The bottlenose dolphin groups did not change their behaviour in response to boat approaches during any of the periods of experimentation. Short-term changes in group speed, group size and spread were not statistically significant. Dolphin groups continued with their ‘normal’ behaviour and spent the same amount of time in the bay when compared to their distribution and behaviour in the absence of the experimental boat. These findings indicate that the experimental boat did not affect the behaviour of dolphins at either a slow or fast approach and even at a close distance. This is interpreted as being as a result of habituation of the dolphins due to their residency in a busy port. This work is crucial in developing guidelines for the development of a sustainable dolphin watching industry off Durban.
A biogeographic study of the KwaZulu-Natal sandstone sourveld patches within the eThekwini Municipal Area.
(2016) Drury, Charmaine Crystal.; Ramdhani, Syd.; Naidoo, Sershen.; Carbutt, Clinton.
KwaZulu-Natal Sandstone Sourveld (KZNSS) is an endangered vegetation type in South Africa. Approximately 68% of KZNSS is transformed, with remaining patches existing within an urban and suburban matrix. Fragmented patches of KZNSS found within the eThekwini Municipal Area (EMA) represent a conservation priority but are often not managed/ conserved appropriately as they are sometimes misclassified as Indian Ocean Coastal Grassland Belt (IOCGB) based on their close proximity to the latter vegetation type in a number of areas. This motivated the present study which involved characterising the flora of eight grassland patches within the EMA presently categorised as follows: three KZNSS sites (viz. Giba Gorge Environmental Precinct, Inanda Mountain and Springside Nature Reserve), three IOCBG sites (viz. Spyhill Open Space, Tanglewood Nature Reserve and Edgecliff Open Space) which are currently called Ecotonal given their close proximity to KZNSS, and two IOCGB sites (viz. New Germany Nature Reserve and Roosfontein Nature Reserve). Floristic surveys, which involved quadrats sampling were performed year round (c. 60% in the winter, 30% in the summer and the remaining quadrats performed in spring or autumn) until an 80% sampling effort was achieved. Additionally, transect sampling was performed monthly for a year at each site. Data from both methods were used to determine the vegetation composition and structure at each site. The below-ground flora of each site was also characterized by removing 30 – 35 soil samples after the two main flowering events (late November and early December as well as late April and early May) at each site and allowing germination to occur, with the resulting germinants being identified and quantified. Field observations on levels of disturbance and management practices at each were also considered. When data for quadrats and transects were pooled, 263 species were found to occur across the eight sites, with 110 of these being common to all three vegetation categories. Only one of the eleven endemic taxa characteristic of KZNSS were found across all three vegetation categories, while none of the endemic taxa associated with IOCBG were found, suggesting iv that identifying KZNSS or IOCBG based on endemic (i.e. diagnostic) species may be inappropriate at the sites investigated here. Further comparisons showed KZNSS and Ecotonal to contain more species than IOCBG, which were spread across more plant families (55 found in total), although IOCBG had one less site than KZNSS and Ecotonal. Diversity measures indicated that Ecotonal is more similar to KZNSS, with more species in common between KZNSS and Ecotonal than Ecotonal had with IOCBG. Additionally, diversity measures show very little differentiation between the dominant taxa of IOCBG from KZNSS. Cluster analyses and ordinations confirmed the current classification of Ecotonal sites as part of IOCBG, despite Ecotonal sharing more superficial similarities with KZNSS. Island biogeography theory‟s area and distance effects were not upheld – most likely due to the sites not being truly isolated from each other and a very localised spatial scale, the limited temporal scale (current status a result of the past 200 years), the lack of a true originating mainland and anthropogenic disturbance. Interestingly, the below-ground flora represented only c. 10% of the species found above-ground for all three categories, with Sørenson similarity index ranging from c. 15 – 22% as opposed to the 50% expected for southern African grasslands. This suggests that seedbank health and hence, regenerative potential may be poor at many of these sites and this may necessitate species reintroduction and habitat restoration at a number of these sites. Additionally, the effects of disturbance were evident across sites in all three vegetation categories, with disturbed sites (Edgecliff Open Space, Inanda Mountain and Roosfontein Nature Reserve) containing fewer species of conservation concern, fewer indigenous taxa in general and more alien plant taxa. Diversity indices also suggest that disturbed sites were more heterogeneous. However, disturbance agents such as herbivory appear to have had an enriching effect in term of the abundance of graminoids within the germinable soil seedbank. Alien taxa also occurred frequently in the below-ground flora but were not noted in the above-ground flora which suggests that given further disturbance/transformation, some of these sites are prone to alien plant invasion. The study suggests that IBT is not applicable to vegetation islands (grasslands in this case) with varying levels of transformation in urban matrices. The results confirm the high levels of transformation reported for sub-tropical grasslands within South Africa, specifically KZNSS, and highlight the need for floristic surveys to delimit different grassland types and in turn ensure their appropriate conservation and/or rehabilitation.
The breeding system and demography of the Transvaal Sesame-bush, Sesamothamnus lugardii (Pedaliaceae)
(2019) Bijl, Alison.; Johnson, Steven Dene.; Midgley, Jeremy J.
The aim of this research was to assess the breeding system, pollination relationship and demography of the Transvaal Sesame-bush, Sesamothamnus lugardii N. E. Br. Ex Stapf. (Pedaliaceae). S. lugardii is an arid savanna succulent shrub which can be found throughout Zimbabwe, southern Botswana and in northern South Africa, where it is anecdotally thought to be rare. Two populations of S. lugardii were assessed in Limpopo, South Africa. The floral traits of S. lugardii suggest that it is specialised for pollination by long-tongued hawkmoths. The flowers bloom in the evening, are large, sweetly scented and pale in colour. The corolla tubes are very long (ca. 10 cm) and narrow. Very long-tongued hawkmoths (Agrius convolvuli) were found to be the only visitors capable of accessing the nectar at the base of the S. lugardii corolla tubes while foraging and simultaneously interacting with the reproductive structures, successfully pollinating the flowers. S. lugardii is an obligate outcrosser, dependent on A. convolvuli hawkmoths for sexual reproduction. The high-risk traits of the S. lugardii breeding system, namely pollinator specialisation and obligate out-crossing, could render S. lugardii vulnerable to extinction. Predation of flowers by scarab beetles in the study population at Mapungubwe National Park resulted in low fruit set. At Morongwa Private Safari Lodge florivory was negligible and fruit set was higher. In both study populations, S lugardii was dominant in patches across the landscape, but only a small proportion of the numerous plants observed were seedlings. Little is known about the population dynamics of S. lugardii, but the absence of seedlings suggests a potentially vulnerable demography. The large shrubs were heavily impacted by meso- and mega-herbivores, but are resilient to herbivory, as they are capable of bark recovery and epicormic resprouting. However, the ever-increasing numbers of large herbivores at Mapungubwe could reach a critical threshold beyond which the populations of S. lugardii lose their resilience, putting them at risk of local extirpation. The number of seedlings in the populations at Mapungubwe decreased between an initial study conducted in 2005 and the recent assessment in 2014. This may be due to sporadic recruitment, but could also indicate a demographic bottleneck limiting seedling establishment. The low-risk traits associated with demography, namely resilience through longevity and vigorous resprouting, offset the high-risk traits by buffering the populations from decline during periods of reproductive failure. The environment in the study populations at present favours the continued survival of S. lugardii, despite the slow population turnover and low rate of reproductive success. Should the environmental conditions become less favourable for S. lugardii, then the extinction risk could greatly increase over a short period of time, and could even result in local extirpation.
Changes in adult female white rhino seasonal home ranges in relation to variation in food quality and availability.
(2013) Hebbelmann, Lisa.; Shrader, Adrian Morgan.; Ward, David Mercer.
As the dry season progresses across southern Africa, the availability and quality of food declines for large herbivores. Female white rhinos compensate for these declines by expanding and/or shifting their home ranges. These changes may be to incorporate habitat types that contain high quality food or quite simply more food. To determine the factors that drive these seasonal changes in home ranges, I focused on dry season changes in the availability and quality of grass in habitats utilised by white rhinos in the Ithala Game Reserve, South Africa. I expected that if food quality was the main driver, white rhinos would follow optimal foraging principles and incorporate habitat types with the highest nutritional quality into their dry season home ranges. Alternatively, due to their large body size (>1000 kg) and thus ability to survive on low quality food, they may rather incorporate habitat types with high food availability. In contrast to previous studies, I found that during the dry season female white rhinos did not increase the size of their home ranges, but rather shifted their home range boundaries. This resulted in individuals increasing the amount of Bushveld and decreasing the amount of Wooded Grasslands within their dry season home ranges. When I explored the different factors that could explain these patterns, I found that changes in the crude protein content of grass was the key factor driving the incorporation and exclusion of habitat types in the home ranges. During the dry season, white rhinos incorporated the habitat that had the smallest seasonal reduction in crude protein content, while excluding the one with the largest decrease in crude protein. As a result, my results suggest that the search for high quality best explains the seasonal home range shifts of female white rhinos in the Ithala Game Reserve.
Community diversity and composition of ground-dwelling arthropods in major habitat types of the KwaZulu-Natal Sandstone Sourveld.
(2023) Mhlongo, Nokukhanya.; Tsvuura, Zivanai.; Munyai, Thinandavha Caswell.
Grasslands constitute over 25% of the global land surface and close to one-third of southern Africa. Natural and semi-natural grasslands are recognized globally for their high biodiversity value and their important contribution to the provision of ecosystem services, including provisioning services such as carbon sequestration, water catchments, and grazing for livestock and wildlife. Nonetheless, grasslands are consistently reduced and threatened by anthropogenic activities and invasive alien plants. Invasive alien plants may hinder the growth of natural vegetation by overconsumption of resources. The impact of invasive alien plants on natural vegetation may indirectly affect plant-to-animal interactions such as specialized pollination and seed dispersal syndromes which may ultimately disturb ecosystem processes. The Sandstone Sourveld in KwaZulu-Natal province of South Africa is a threatened grassland ecosystem as a result of various anthropogenic disturbances. Knowledge of arthropod response to differences in habitat types may be essential for an improved understanding of the structure and functioning of ecosystems, which is relevant for informing conservation practice. The aim of this study was to investigate the composition and diversity patterns of ground-dwelling arthropods (ants, beetles, Orthopterans, and spiders) in three habitat types (forest, intact grassland, and disturbed grassland) at Springside and Tanglewood Nature Reserves, which occur in the KwaZulu-Natal Sandstone Sourveld (KZNSS). The objectives were: (i) to document the response of the ground-dwelling arthropod community in different habitat types, (ii) to determine the impacts of seasonal change on the abundance and richness of ground-dwelling arthropods at the two sites, and (iii) to determine the correlation between the distribution of ground-dwelling arthropods and soil characteristics in the KZNSS. Ground-dwelling arthropods were sampled in Springside and Tanglewood Nature Reserves using pitfall traps in each habitat type. Soil parameters in the habitats were also assessed. Analysis of variance was used to test for differences in arthropod morphospecies richness and abundance viii across the habitat types and between seasons. The Shannon-Weiner diversity index was computed and used to compare the diversity of ground-dwelling arthropods between the two sites and among habitat types. Ground-dwelling arthropods showed varying patterns in response to habitat characteristics and the disturbance gradient at Springside and Tanglewood. Intact grassland was the most diverse habitat in both Springside and Tanglewood. In Tanglewood, the abundance of ants was greater in disturbed grassland which consisted of a variety of alien invasive shrubs, the high abundance was explained by the “intermediate disturbance hypothesis”. However, alien invasion showed more negative than positive impacts on the abundance and composition of ground-dwelling arthropods when there was a significant decrease in the abundance and composition of ants, beetles and spiders. Species richness of ants and beetles was higher in the wet than dry season whereas Orthopterans and spiders showed no significant difference between seasons. In all arthropod groups, a greater number of species were correlated to soil potassium, soil pH, and soil bulk density. Overall, the intact grassland had the highest species richness and abundance followed by the forest and lastly the disturbed grassland. The greater abundance of ants, beetles, and spiders in the pristine grasslands of KZNSS shows that there is still a need to conserve the remnants of the KZNSS vegetation. Therefore, the conservancy management is urged to consider the eradication of alien invasive plants. Future studies are recommended to consider the volant and vegetation canopy arthropods as they are all interdependent with ground-dwelling arthropods to form a whole community of arthropods in an ecosystem.
Comparative water relations of Protea nitida seedlings and sprouters after fire.
(1990) Smith, Rosemary Elizabeth.; Pammenter, Norman William.
This study was undertaken to determine the effect of vegetation structure (the ratio of re-seeding to re-sprouting plants) on post-fire catchment water yield. Plant communities are the only components of mountain catchments which can be manipulated to augment water supplies on any practical scale. Burning, which is one of the options available to catchment managers, reduces plant biomass and increases water yield by reducing transpiration and interception losses. Communities dominated by re-seeding species tend to recover more slowly after fires than when sprouters predominate. The rate of vegetation recovery will determine the rate at which streamflow returns to pre-fire levels. Sprouters may use more water than seeders in the early post-fire period by virtue of their greater leaf area, which both increases interception and transpiration losses. Leaf area development could be used as a simple determinant of post-fire water yield if transpiration losses per unit leaf area are similar in seedlings and sprouters. In this study, a comparison was made of the transpiration rates of seedlings and sprouters of Protea nitida after a fire in Swartboskloof (Cape Province) in 1987. Plant water potentials were determined (index of the degree of stress) and leaf stomatal conductances were measured. Results indicate that transpiration rates are similar throughout the year except during the short summer drought period when the seedlings have comparatively low transpiration rates (< 1 mmo1 m-2 s-1 compared to 2-3 mmo1 m-2 s-1 of the sprouter), and i immediately after the first winter rains where the seedlings have comparatively high rates (approxi.mately 4 mmol m-2 s-1 compared to 2 mmol m-2s-1.) The 1ow summer rates are thought to be the result of drought stress induced by limited water supply and the shallow root systems of the seedlings. The higher winter rates suggest that the shallow surface roots of the seedlings respond quickly to increased surface moisture. Differences in root structure (Le. shallow seedling roots and well-developed deep sprouter roots) rather than regeneration mode appear to be responsible for the marginal differences observed in transpiration rates. These differences are expected to disappear as seedling roots develop and occupy the profile. Leaf area could therefore, be used as a determinant of catchment water yield.
The competitive effect of vetiver grass on native grasses and implications for grassland rehabilitation in South Africa.
(2018) Dlamini, Lindokuhle Xolani.; Kirkman, Kevin Peter.; Tedder, Michelle Jennifer.
Astract available in PDF file.
The contribution of goats to household food security in selected communities of KwaZulu-Natal, South Africa.
(2021) Khowa, Anele Aurelia.; Kraai, Manqhai.; Tsvuura, Zivanai.
The growth of the human population in the world has been occurring at a rapid rate. This presents a challenge of how the world food demands will be met. These challenges are always felt the most in developing countries, and result in a lot of people in developing countries turning to alternative sources of income other than employment to manage their food situation. One of the alternatives includes a reliance on animal husbandry in order to meet and improve their livelihoods particularly with respect to food. Furthermore, small-scale farming of animals such as goats, sheep, pigs and chickens has also been an income source when the animals are sold. In developing countries, pastoralism and agro-pastoralism frequently occur among disadvantaged communities, who are often found in arid or semi-arid regions. As a result, goats have been shown to be an important type of livestock that can be kept in such conditions without financially stressing their owner by requiring constant care of supplementary feeds and medication. Goats are known for their resilience which allows them to cope with stressful conditions while being able to reproduce. This resilience and productivity of goats allows their owners to be able to liquidate them for cash if there is a need and also be able to slaughter them for their household consumption. Here, I investigated the contribution of small-scale goat farming to household food security in rural and peri-urban areas in KwaZulu-Natal (KZN), South Africa. The study was carried out in rural and peri-urban areas of Msinga, Kokstad, Howick and Pietermaritzburg in KZN. I used structured questionnaire surveys to determine the contribution of goats to household food security from the farmers’ responses. The questions asked related to the sale of goats (number, sex, age and sale value of the animal) and how the money generated from goat sales was spent. The study also determined goat sales from 27 households in three villages occurring in Msinga over a 2- year period of 2017 to 2018. I also assessed the participation of small-scale farmers in two livestock auctions, which took place in 2019 and 2020 by recording the age, sex, and coat-colour of the animals taken to auctions. The results obtained from the study showed that goats played a role in household food security as a source of cash as well as consumption in strenuous times. These findings of the study highlight that smallscale goat farming provides an alternative food source and income source for disadvantaged farmers. These findings were more prevalent in the rural areas, which kept more goats than those found in the peri-urban areas. Goats in rural areas ranged from 5 to 150 goats in a herd, and 5 to 50 goats in a herd while in periurban areas. Goats were a source of cash in numerous ways including sale of skins after slaughter that are used to craft household items such as stools that can be sold for cash. Adult goats were sold more at the farmers’ homesteads than auctions where buyers opted for younger goats. My results also showed that small-scale farmers use all possible avenues to sell their goats, as they sold a high number of animals from home and did not depend on infrequent livestock auction events. However, there were benefits derived from participating in auctions in terms of the relatively higher prices obtained there. For example, female and male goats sold for R2 177 and R1 268, respectively at auctions. The price was similar for females (R1 083) and males (R1 065) in homesteads. At auctions, female and male goats sold for R2 177 and R1 268, respectively. From homesteads, female and male goats sold for R1 083 and R1 065, respectively. Colour of goats proved to be an important trait at auctions as light-coloured goats were in higher demand than black goats. Homestead sales also remain a useful practice as farmers generate income to assist in day-to-day household expenses instead of waiting for infrequent auction events. Furthermore, small-scale farmers who plan to participate in auctions should pay attention to the characteristics (age, colour, and sex) of their animals when populating their herds. Sub-adult, light-coloured and female goats were the animals that were highly sought after at auctions.
Development and application of novel ornithological survey methods for the detection of cryptic avian indicator species that predict grassland health.
(2021) Beaumont, Stuart Nicholas.; Downs, Colleen Thelma.
The anthropogenic pressure on South African grasslands to meet the needs of the burgeoning human population has exposed them to extensive permanent transformation and degradation. Indicator species may identify changes in the grassland ecosystem. One such indicator species for natural sourveld grassland condition in South Africa is the red-winged francolin (Scleroptila levaillantii), whose population density is negatively correlated to grazing intensity and annual burning. Pointing dogs (Canis lupus familiaris) have been used extensively to aid ecologists in detecting these and other cryptic gamebirds to establish abundance. Here, a reliable method was developed to count cryptic gamebirds in the Greater uMgeni Vlei Expansion Area, KwaZulu-Natal Midlands, South Africa, where the route through a survey site was flexible. A variation to the existing distance sampling technique was proposed where the dog global positioning system (GPS) track was the transect line. The study investigated the effect of varying environmental conditions on the distance from which a pointing dog could reliably and consistently detect a bird and allow calculating a detection distance based on influential environmental variables. Between March – October 2021, using pointing dogs fitted with GPS devices, controlled and uncontrolled trials were conducted on Japanese quail (Coturnix japonica) and red-winged francolin in their natural habitat, respectively, to establish the environmental conditions that affect detectability and the detection distance from which a dog can detect a bird of known location. A total of 21 surveys were conducted (August 2020 – October 2021), on four survey sites by one or two pointer dogs fitted with GPS devices, to establish the population densities and territory of red-winged francolin. Individual area of search, established from the detection distance based on nominal wind speed and GPS track, was calculated. The redundancy in area of search enabled the evaluation of relative proficiency of detection of red-winged francolin. Of the environmental variables monitored, only nominal wind speed significantly influenced detection distance, where an increase of one-knot wind strength resulted in an increase in detection distance by 0.64 m. This enabled an area of search, considerate of influential environmental conditions, to be derived and the probability of detection within that search area = 1. Results showed significantly better precision and accuracy when surveying with two dogs when compared with one dog. The calculation of detection distance, where the probability of detecting a bird at this distance = 1, addresses the bias of varying scenting conditions. The established area of search, where the probability of detecting a bird within this area = 1, addresses the situation where known coveys in an area of known size remain undetected. Since the area of search is independent of time spent searching and normalised for redundancy, the bias introduced by varying physical aptitude is mitigated. Consideration for the application of this method should be given to the environmental conditions under which the surveying is planned since the detection distance function is derived for conditions at the present study sites. These techniques, based on a variable survey route through the survey site, may be used by citizen scientists to assist land managers, conservationists, and ecologists in establishing the abundance of red-winged francolin, contributing to burning and grazing regime management to enhance conservation efforts for the species.

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