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Implementation of a science-action partnership to manage a threatened ecosystem in an urban context

Determining the diversity of nocturnal flying insects of the grassland in the Krugersdorp Nature Reserve

  • Authors: Pretorius, Estherna
  • Date: 2012-05-02
  • Subjects: Nocturnal flying insects , Cradle of Humankind World Heritage Site (South Africa) , Krugersdorp Nature Reserve (South Africa) , Grassland ecology , Bats - Ecology , Biodiversity conservation
  • Type: Thesis
  • Identifier: uj:2246 , http://hdl.handle.net/10210/4685
  • Description: M.Sc. , The grassland biome of South Africa harbours rich ecosystem diversity. Some of the distinctive features of grassland biodiversity in South Africa include globally significant centres of plant endemism, half of the country's endemic mammal species, a third of its endangered butterfly species and 10 of 14 of its globally threatened bird species. Grassland is one of the most inadequately maintained biomes in Southern Africa because 23% is under cultivation, 60% is irreversibly transformed and most of the remaining natural area is used as rangeland for livestock. Only 2% of the grassland biome is currently protected. Grasslands provide essential ecosystem services for economic development, but this biome also supports a large human population whose resource demands have serious environmental implications that threaten the grasslands‘ biodiversity. Urbanisation is possibly one of the major immediate threats to the grassland ecology in South Africa. This is also the case in the Cradle of Humankind World Heritage Site (COHWHS) and adjacent areas. New housing complexes and informal housing are encroaching on the COHWHS. Indigenous fauna and flora are being affected by ecologically insensitive urban development. This poses a major threat to the fauna of this region including the insects that occur in grassland habitats. The insects play a vital role as pollinators in grassland habitats and form an essential food source to a range of predators, including grass owls, shrews, bull frogs, lizards and bats. In order to conserve the insects and therefore the food web of which they form part, it is necessary to understand the diversity of the insects in the grassland in the dolomitic areas. The COHWHS is a world renowned heritage site devoted to the origin of humankind and is characterised by dolomitic caves. These caves are also the home of a large population of bats consisting of several species. The negative impact on the grasslands in the COHWHS and surroundings pose a threat to the survival of these bat populations if the food source they depend on is negatively affected. For this reason it is important to determine which flying nocturnal insect species are available in the grasslands surrounding bat roosts in the COHWHS and surroundings. 3 The choice of location for the primary trap site was made on the basis of its proximity to known bat roosts and the fact that it is situated in a nature reserve that, although the river is polluted, contains an otherwise relatively unspoilt grassland habitat. Sampling took place over a period of 14 months during which fluctuations in the insect population was observed. The fluctuations can be ascribed to seasonal climate changes and the three veld fires that occurred during this period. This fluctuation was most evident in the representatives of the Orders Lepidoptera and Coleoptera sampled.
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Conservation of South African tortoises with emphasis on their apicomplexan haematozoans, as well as biological and metal-fingerprinting of captive individuals

  • Authors: Cook, Courtney Antonia
  • Date: 2012-11-02
  • Subjects: Tortoises - Conservation , Testudinidae - Conservation , Testudinidae - Evolution , Testudinidae - Identification , Biodiversity conservation
  • Type: Thesis
  • Identifier: uj:7320 , http://hdl.handle.net/10210/8058
  • Description: Ph.D. , South Africa has the highest biodiversity of tortoises in the world with possibly an equivalent diversity of apicomplexan haematozoans, which to date have not been adequately researched. Prior to this study, five apicomplexans had been recorded infecting southern African tortoises, including two haemogregarines, Haemogregarina fitzsimonsi and Haemogregarina parvula, and three haemoproteids, Haemoproteus testudinalis, Haemoproteus balazuci and Haemoproteus sp. A. The taxonomy of all of these species was questionable, and therefore one goal of this study was to examine at least some in great detail with the view to resolving taxonomic issues. This involved using a number of techniques such as light microscopy and image analysis, transmission electron microscopy, and molecular analysis. Outcomes were the transfer of one Haemogregarina species (Haemogregarina fitzsimonsi) to the genus Hepatozoon, the suggestion that the genus Hemolivia might be more appropriate for another haemogregarine (Haemogregarina parvula), the synonymisation of two known species of Haemoproteus (Haemoproteus balazuci with Haemoproteus testudinalis), and the naming of a third haemoproteid (Haemoproteus natalensis Cook, Smit and Davies, 2010). In addition, a likely new species of haemogregarine (Haemogregarina sp. A.) was described. To achieve all this, 367 tortoises were collected representing 62% of the species and all five genera, of South African tortoises. Tortoises were both wild (287) and captive (80), with these being both live (270) and dead (97) when taken. They were located in four different provinces, including Gauteng, KwaZulu-Natal, the Northern and the Western Cape, and in four different biomes (semi-arid grassland, Kalahari desert, subtropical thorn bushveld, and coastal endemic fynbos). Light photomicroscopy examination of Giemsa stained peripheral blood smears prepared from the subcarapacial vessels of live tortoises allowed for descriptions and comparisons of the observed haematozoans. Of the live tortoises, 14.8% had haemogregarines, including 13.3% with H. fitzsimonsi, 0.7% with H. parvula, and 0.7% with a previously unknown, intraleucocytic, Haemogregarina sp. A. A further 1.1% had haemoproteids, including 0.7% with Hp. testudinalis/Hp. balazuci and 0.4% with Haemoproteus sp. A. The host and locality records of previously described haematozoan species were increased and records for likely new species provided. Subtropical areas (KwaZulu-Natal) compared to arid regions (Northern Cape) presented with a higher diversity of apicomplexans, along with a higher prevalence of ticks, possible vectors of the tortoise blood parasites. Overall, male tortoises had the highest haematozoan and tick prevalences compared to females and juveniles,
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Captive breeding and conservation : lessons from captive lion breeding

Biodiversity and systematics of apicomplexan parasites infecting South African leopard and hinged tortoises

  • Authors: Cook, Courtney Antonia
  • Date: 2010-03-15T06:35:51Z
  • Subjects: Leopard tortoise parasites , Hinged-back tortoises parasites , Protozoan diseases , Biodiversity conservation
  • Type: Thesis
  • Identifier: uj:6677 , http://hdl.handle.net/10210/3081
  • Description: M.Sc. , Research into blood protozoans (haematozoans) infecting African tortoises is scanty with only a few records published, many during the early part of the last century. Little research had been done on the blood parasites of tortoises examined in this study namely, Kinixys lobatsiana, K. belliana belliana, K. natalensis, Geochelone pardalis pardalis, G. pardalis babcocki and Chersina angulata. The study therefore aimed to: 1) examine apicomplexan haematozoan parasites infecting several of South Africa’s indigenous tortoises and compare them with published species descriptions, especially from neighbouring Mozambique; 2) provide host details (identity, ectoparasites, host weight and gender, effects of blood parasites on host cells) and locality records in different seasons for described and new apicomplexan species; 3) describe new and recorded parasites using morphometrics and, if possible, ultrastructural characteristics 4) attempt apicomplexan DNA extraction, amplification and, if feasible, purification; and 5) establish a basis for future research as a result of the acquired knowledge. During the current study, 154 tortoises of six species in three genera, both captive and wild, and from four South African provinces (Gauteng, North West, Kwazulu-Natal and Western Cape) were sampled. Giemsa stained blood smears and use of image analysis enabled morphometric analysis of the apicomplexans and their effects on host cells, while some blood preserved in Karnovsky’s and Todd’s fixatives received detailed examination by transmission electron microscopy. Lastly, blood preserved in lysis buffer during collection, and with the highest parasitaemias, was subjected to parasite DNA extraction and amplification. Comparisons between a published account of apicomplexans recorded from K. b. belliana in Mozambique, and those found in the current study, identified two haemogregarine species. In the present research, Haemogregarina fitzsimonsi Dias, 1953 infected 2/27 (7%) wild North West K. lobatsiana, 2/3 (66%) captive Kwazulu-Natal K. natalensis, 7/14 (50%) captive Kwazulu- Natal K. b. belliana, 3/6 (50%) captive Kwazulu-Natal G. p. pardalis, 2/41 (5%) wild G. p. babcocki and 13/37 (35%) captive Gauteng G. pardalis. In addition, Haemogregarina parvula Dias, 1953, infected 2/14 (14%) captive K. b. belliana and 1/10 (10%) captive G. p. pardalis. An unknown species of haemogregarine, possibly also H. fitzsimonsi occurred in 6/16 (38%) Chersina angulata from the Western Cape. As well as haemogregarines, two haemoproteids were identified: Haemoproteus balazuci Dias, 1953 infected 2/27 (7%) wild North West K. lobatsiana, 2/2 (100%) captive Gauteng K. lobatsiana and 1/41 (2%) wild North West G. p. babcocki; Haemoproteus sp., a likely new species, was found in 1/3 (33%) captive K. natalensis. Infections with Haemogregarina and Haemoproteus were not concurrent in this study, but were found to occur concurrently in Dias (1953) findings, and only the two Haemogregarina spp. occurred together in captive Kwazulu-Natal G. p. pardalis tortoises, which do not occur naturally in the region. Haemogregarina fitzsimonsi did not appear region or host specific, since it infected 5/6 species of tortoises from all provinces sampled. Haemogregarina parvula apparently existed only in tortoises from Kwazulu-Natal. Furthermore, captive Gauteng female tortoises were found to have a higher rate of infection than males and heavier tortoises showed a lower intensity infection than lighter and younger tortoises. On average season appeared to have a slight affect on parasite prevalence, with a higher prevalence during the summer rather than the winter, possibly a result of the activity of the assumed vector, which may be the tick species Amblyomma marmoreum (found on G. pardalis) and/or Amblyomma hebraeum (found on C. angulata). For the new Haemoproteus sp., the small sample size meant that meaningful data on host-specificity and range was not gathered, but Hp. balazuci occurred in K. lobatsiana in the drier regions of the North West and Gauteng. Although DNA extraction was possible for H. fitzsimonsi, the technique requires further refinement and samples with greater parasitemias before it can be used with additional material, and sequencing can be attempted. Thus, new localities, hosts, host data and possible vectors (ticks) were recorded for the apicomplexan species identified by Dias (1953) and they were re-described using modern techniques. Also, possibly new Haemogregarina and Haemoproteus spp. were recorded, but their identity requires confirmation by DNA analysis. It is anticipated that these, and future results, will increase the knowledge of the ecology and biodiversity of apicomplexan haematozoans parasitising chelonian hosts in South Africa, with possible application to the conservation of these and other tortoise species around the world.
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A spatial prioritization of threats to biodiversity and conservation in the proposed Magaliesberg biosphere

A global trend towards the loss of evolutionarily unique species in mangrove ecosystems

  • Authors: Daru, Barnabas H. , Yessoufou, Kowiyou , Mankga, Ledile T. , Davies, T. Jonathan
  • Date: 2013
  • Subjects: Mangrove ecology , Threatened species , Biodiversity conservation
  • Type: Article
  • Identifier: uj:5984 , http://hdl.handle.net/10210/8604
  • Description: The mangrove biome stands out as a distinct forest type at the interface between terrestrial, estuarine, and near-shore marine ecosystems. However, mangrove species are increasingly threatened and experiencing range contraction across the globe that requires urgent conservation action. Here, we assess the spatial distribution of mangrove species richness and evolutionary diversity, and evaluate potential predictors of global declines and risk of extinction. We found that human pressure, measured as the number of different uses associated with mangroves, correlated strongly, but negatively, with extinction probability, whereas species ages were the best predictor of global decline, explaining 15% of variation in extinction risk. Although the majority of mangrove species are categorised by the IUCN as Least Concern, our finding that the more threatened species also tend to be those that are more evolutionarily unique is of concern because their extinction would result in a greater loss of phylogenetic diversity. Finally, we identified biogeographic regions that are relatively species-poor but rich in evolutionary history, and suggest these regions deserve greater conservation priority. Our study provides phylogenetic information that is important for developing a unified management plan for mangrove ecosystems worldwide.
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