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Postharvest disinfestation of Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) in citrus fruit can be achieved through cold treatment, but chilling injury becomes increasingly problematic with lower temperature and longer exposure to the treatment. Ionising radiation is an alternative treatment, but also has a dose dependent negative effect on fruit quality. The potential of including both a reduced radiation dose and a less detrimental cold treatment in a combination treatment was assessed. The effects of 40 to 70 Gy radiation and cold treatments of 0.6 °C to 7.0 °C for periods of 10 to 22 days by themselves and in combination, were investigated on mature larvae in artificial rearing diet. It was demonstrated that various combinations of the two methods can act together to potentially provide adequate control, with the prospect of moderated fruit quality effects due to the reduced intensity of the component treatments. A combination treatment consisting of 60 Gy followed by 16 days at 2.5 °C was identified for further evaluation as a combination treatment that could potentially be validated at the probit-9 level of efficacy. [ABSTRACT FROM AUTHOR]

False codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), is indigenous to sub-SaharanAfrica. It infests a large number of wild plants and can be a pest of commercial concern in cultivated fruit and nuts. A limited number of insecticides, as well as biological control and mating disruption can be applied as control measures in citrus, but they often do not reduce pre- and post-harvest crop loss adequately. The potential of the sterile insect technique (SIT) for the control of T. leucotreta was investigated between 2002 and 2006 in Citrusdal, Western Cape Province, South Africa, and entailed studies on radiation biology and F1 sterility, compatibility with the egg parasitoid Trichogrammatoidea Nagaraja (Hymenoptera: Trichogrammatidae), and field cage experiments to determine sterile:fertile moth overflooding ratios. Promising results justified a pilot experiment conducted on semi-commercial scale in citrus orchards in Citrusdal during 2005-06. One thousand mixed sex moths were treated with 150 Gy ionising radiation and released in 35 ha ofWashington navel oranges twice a week for 28 weeks during the production season. The moths were released by hand from an all-terrain vehicle, with release rows 40mapart and the numbers of released and feral moths monitored weekly with pheromone traps. Released moths dispersed well and fully overlapped between release rows. The target overflooding ratio of released to feral males (10:1) was exceeded by wide margins and ameanoverflooding ratio of 41:1 was maintained during the experiment. Fruit drop assessments were conducted once a week in the SIT-treated and control orchards. Crop loss due to T. leucotreta infestation was reduced by 95.2 % in the SIT-treated area compared to the control orchard. The project resulted in the commercialisation of the SIT for T. leucotreta on citrus. [ABSTRACT FROM AUTHOR]

This study investigated the systematics and phylogeography of a threatened tortoise of South Africa, the speckled padloper Homopus signatus. Sixty three specimens were collected from 17 localities that covered the distributional range of the two subspecies in western South Africa and a north-eastern population that was recently discovered near Pofadder. The Pofadder sample could not be assigned to either subspecies based on morphology. The samples were sequenced for two partial mtDNA fragments, nicotinamide adenine dinucleotide dehydrogenase component four and cytochrome b, which yielded ∼1.1 kb, while a subset of the samples were sequenced for a 390 bp nuclear DNA (nDNA) fragment of prolactin. Phylogenetic analyses of mtDNA using minimum evolution, maximum parsimony and Bayesian inferences supported the monophyly of H. signatus and revealed that the Pofadder specimen was basal in the topology and sister to the remainder. The phylogenetic analyses did not support the recognition of two subspecies; there was statistical support for a Homopus signatus signatus clade but Homopus signatus cafer was not monophyletic. The nDNA analysis showed no difference between the subspecies and placed the Pofadder sample distant but not distinct from H. s. signatus. The mtDNA and the nDNA data suggest that the subspecies are invalid taxonomic units. The structure of the mtDNA network corresponded to the geographical distribution of populations. The north-western populations formed one haplocluster, corresponding to H. s. signatus, whereas the south-western populations formed three haploclusters, corresponding to H. s. cafer. The Pofadder sample was unconnected to the network. The morphology of the northern and southern morphotypes probably reflects selection for crypsis on the different substrate types of the regions, granites and sedimentary rocks, respectively. These results highlight that subspecies designations should be authenticated by molecular techniques because morphological plasticity can obfuscate phylogenetic relationships. We consider the western H. signatus populations as one taxonomic unit and recommend wider sampling of the Pofadder locality to clarify the taxonomic status of this lineage. [ABSTRACT FROM AUTHOR]

As a charismatic carnivore that is vulnerable to extinction, many studies have been conducted on predation by the cheetah Acinonyx jubatus. Cheetah are generally considered to capture medium-sized prey; however, which species are actually preferred and why has yet to be addressed. We used data from 21 published and two unpublished studies from six countries throughout the distribution of the cheetah to determine which prey species were preferred and which were avoided using Jacobs' index. The mean Jacobs' index value for each prey species was used as the dependent variable in multiple regression, with prey abundance and prey body mass as predictive variables. Cheetah prefer to kill and actually kill the most available prey present at a site within a body mass range of 23–56 kg with a peak (mode) at 36 kg. Blesbok, impala, Thomson's and Grant's gazelles, and springbok are significantly preferred, whereas prey outside this range are generally avoided. The morphological adaptations of the cheetah appear to have evolved to capture medium-sized prey that can be subdued with minimal risk of injury. Coincidentally, these species can be consumed rapidly before kleptoparasites arrive. These results are discussed through the premise of optimality theory whereby decisions made by the predator maximize the net energetic benefits of foraging. Information is also presented that allows conservation managers to determine which prey species should be in adequate numbers at cheetah reintroduction sites to support a cheetah population. Conversely, these results will illustrate which potential prey species of local conservation concern should be monitored for impact from cheetahs as several species are likely to be preyed upon more frequently than others. [ABSTRACT FROM AUTHOR]

The small tortoises of southern Africa include the only testudinid taxa that produce single-egg clutches. This group includes the world's smallest tortoise, Homopus signatus (Gmelin, 1789), which inhabits a harsh, arid environment. Climate and body size may influence reproductive output, so we hypothesized that the east–west aridity gradient in southern Africa affects egg and clutch size of the small indigenous tortoises, and that the morphology of H. signatus constrains egg size, preventing the formation of optimal eggs. Here we show that aridity and unpredictable rainfall determine which of these tortoise taxa produce single-egg clutches. Taxa in less predictable environments produce larger eggs relative to body size than do taxa in more predictable environments. Homopus signatus produces the largest egg relative to body size, probably to enhance offspring survival in its harsh environment. Body size, pelvic aperture size, and the narrow anal gap of H. signatus appear to constrain egg size. Despite these constraints, females produce rigid-shelled eggs larger than the pelvic canal and use pelvic kinesis to pass eggs at oviposition; both features are unknown in other chelonians and emphasize the selective advantage of large eggs to H. signatus. [ABSTRACT FROM AUTHOR]

To overcome constraints on ionising radiation and cold treatment as stand-alone disinfestation treatments for Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) in citrus fruit, the efficacy of a combination treatment consisting of ionising radiation and cold, both at reduced doses, was tested at the probit-9 level. Earlier research indicated that combination treatments involving ionising radiation and cold suppressed larvae and their successive development stages more effectively than the individual treatments. The probit-9 level efficacy (at least 93 613 insects) of a treatment combination comprising 60Gyof ionising radiation followed by cold exposure for 16 days at 2.5 °C was evaluated. A total of 104 617 mature, fifth instars was treated. Larval mortality was 99.7%and 50.2%of the subsequent pupae died. A total of 143 moths with a sex ratio of one female to 7.9 males eclosed. Only 4.8%of the moths were able to fly. No eggs were produced by the moths in mating studies. The probit-9 level efficacy of the combination treatment was validated, indicating that it meets the efficacy requirements for utilisation as a phytosanitary disinfestation treatment for T. leucotreta in citrus fruit in international trade. [ABSTRACT FROM AUTHOR]

Translocation is a valuable conservation tool, but poses significant risks for the transported rhinoceroses. Interventions reducing these risks are required to ensure positive welfare during transportation. The aim of this study was to evaluate the effect of journey duration and feeding during the transport of white rhinoceroses (Ceratotherium simum simum). A total of 32 animals were transported by road during two events, five days apart. Fifteen rhinoceroses in the first transport event (37.0 ± 2.4 hr duration) were not fed, while 17 rhinoceroses in the second event (32.2 ± 1.5 hr duration) were offered lucerne. Blood samples were collected at capture and after transport for the evaluation of changes in serum clinical chemistry analytes. The Wilcoxon rank-sum test was used to compare differences between the groups. In all rhinoceroses, transport resulted in changes in serum electrolyte, metabolite and enzyme concentrations, indicating a loss in total body water, nutritional shifts, stress and fatigue. Fed rhinoceroses, transported over a shorter time, displayed greater changes in osmolality (p < 0.006), serum sodium and chloride concentrations (p = 0.005 and = 0.001, respectively) indicating a greater degree of total body water loss than non-fed rhinoceroses. Feeding and a shorter transport duration reduced, but did not prevent, nutritional challenges. A greater increase in the muscle enzymes CK and AST (p = 0.027 and = 0.001, respectively), indicated greater fatigue in non-fed rhinoceroses transported over a longer time. Further work to distinguish the effects of feeding and journey duration is required to better understand the role feeding may play in mitigating welfare challenges during rhinoceros translocation. [ABSTRACT FROM AUTHOR]

In South Africa, more than 30 small, enclosed game reserves have reintroduced lions over the last two decades, which now house more than 500 individuals. There is a high risk of inbreeding in these fragmented, fenced and isolated populations, which may be compounded by a lack of management guidelines. A population of 11 founder lions Panthera leo was reintroduced to Madikwe Game Reserve in 1995, and this population has in turn become a source for reestablishing other populations. Only four lineages were reintroduced, founder males were related to founder females, and since 1997, only one male lineage maintained tenure for >9 years, resulting in breeding with direct relatives. Interventionist management to limit lion population growth and inbreeding in Madikwe has taken the form of translocating, trophy hunting and culling of mainly sub adult lions. Despite this management, inbreeding started 5 years after reintroduction. Reproductive performance and thus population growth in Madikwe were dependent on the overall lion population density. When lion density was low, females first gave birth at a significantly younger age and produced larger litters, resulting in a high population growth rate, which decreased significantly when lion density in the park reached carrying capacity, that is, 61 lions. This might have profound consequences for future reestablishment of lion populations when restocking new reserves: our study illustrates the need for founder populations of reintroduced endangered predator species to be as large and genetically diverse as possible, and thereafter new genetic material should be supplemented. The development of such management guidelines is becoming very important as large predator populations become increasingly fragmented and managed as metapopulations. [ABSTRACT FROM AUTHOR]

The angulate tortoise Chersina angulata is unique among South African tortoises in having a single unpaired gular (extension of the ventral plastron) that is used to ram and overturn rival conspecifics. This behaviour has earned it the reputation of a ‘fighting tortoise’, and in this paper we test the hypothesis that the morphology of this tortoise is a result of intrasexual selection. Research was carried out on the tortoise population of Dassen Island in September 2004. Tortoises were captured and processed (body mass and five morphological measurements) in situ in the field. A total of 144 males and 99 females were sampled. Males were significantly larger than females for all body parameters measured. Males had significantly longer gulars ( F=17.783, P<0.005, n=242) and greater posterior carapace width ( F=143.664, P<0.005, n=242) relative to body size than females. A total of 66 male–male interactions was observed in the field. Males that won fights were significantly longer than males that lost fights ( t=2.238, P<0.034, n=28) and had significantly greater rear carapace width relative to middle carapace width ( F=5.591, P=0.026, n=28). Gular length was found to be irrelevant to fighting success. Tortoises of both sexes were placed upside down to compare righting ability. Males were significantly more successful at righting themselves than females ( χ2=5.347, P=0.0208, n=70). It was concluded that posterior carapace width is a more important variable than gular length in determining male fighting success, and it is suggested that, in addition to righting ability, posterior carapace width may well be a trait under sexual selection in male angulate tortoises. [ABSTRACT FROM AUTHOR]

Social integration is an important factor when reintroducing group‐living species, but examples of the formation of social groups before reintroduction are largely lacking. African wild dogs Lycaon pictus are endangered, and reintroductions have become a routine part of range expansion in South Africa. Wild dogs form packs that are essential to their reproduction and survival, and artificial pack formation is often required before reintroduction. We examined the proximate (i.e. social integration) and ultimate (i.e. reproduction) success of 43 artificial pack formation attempts in the South African managed metapopulation, between 1995 and 2018. The top (and dominant) model for proximate success included an interaction between total group size and an initial separation fence. Larger groups took longer to integrate, irrespective of initial separation, whereas smaller groups brought together immediately integrated faster than those that were initially separated. The top models for ultimate success included an interaction between the proportion of males and number of days spent in the pre‐release enclosure, the total number of days in the enclosure and an interaction between the proportion of captive‐sourced individuals and the total number of days in the enclosure. Ultimate success increased when packs spent less time in the enclosure, especially if those packs had a low proportion of males (i.e. female biased) or included >25% captive‐sourced individuals. Neither the size of the artificially created pack nor the season in which the pack was released affected ultimate success. The success of social integration and reproductive success of artificially formed packs in this study was higher than for natural pack formations. We provide guidelines for optimizing future artificial pack formation in wild dogs for reintroduction success. Our results serve as an example of the practical importance of social behavior in successfully implementing conservation measures for group‐living species. [ABSTRACT FROM AUTHOR]

Foot-and-mouth disease ( FMD) inflicts severe economic losses within infected countries and is arguably the most important trade-restricting livestock disease in the world. In southern Africa, infected African buffaloes ( Syncerus caffer) are the major reservoir of the South African Territories ( SAT) types of the virus. With the progressive expansion of transfrontier conservation areas ( TFCAs), the risk of FMD outbreaks is expected to increase due to a higher probability of buffalo/livestock contacts. To investigate the dynamics of FMD within and around the Great Limpopo TFCA ( GLTFCA), 5 herds of buffaloes were sampled in June 2010 to characterize circulating viruses in South Africa and Zimbabwe. Three SAT-2 and three SAT-3 viral strains were isolated in both countries, including one that was genetically linked with a recent SAT-2 outbreak in Mozambique in 2011. In addition, two groups of unvaccinated cattle ( n = 192) were serologically monitored for 1 year at the wildlife/livestock interface of Gonarezhou National Park ( GNP) in Zimbabwe between April 2009 and January 2010, using the liquid-phase blocking ELISA ( LPBE) and a test for antibodies directed against non-structural proteins ( NSP). Neither clinical signs nor vaccination of cattle were reported during the study, yet a high proportion of the monitored cattle showed antibody responses against SAT-3 and SAT-1. Antibodies against NSP were also detected in 10% of the monitored cattle. The results of this study suggest that cattle grazing in areas adjacent to the GLTFCA can be infected by buffalo or other infected livestock and that cattle trade movements can act as efficient disseminators of FMD viruses to areas several hundred kilometres from the virus source. Current methods of surveillance of FMD at the GLTFCA interface seem insufficient to control for FMD emergence and dissemination and require urgent reassessment and regional coordination. [ABSTRACT FROM AUTHOR]

Abstract: A resurvey of a sample of marula trees (n =474) in the Kruger National Park (KNP) originally documented in 2001, was conducted in 2008 to determine the response of this population segment to the conditions prevalent during that time. These included an increasing elephant population and changes to the KNP fire policy. The overall mortality rate was estimated to be 2.6% per annum, with the mortality rate for individuals >5 m in height being 3.7% per annum. The highest level of mortality was found in the 5–8 m height class (7.1% per annum), while the highest number of dead individuals occurred in the 11–15 m height class (25). In addition minimal recruitment into the seedling size class was observed (n =6). No growth of saplings less than 2 m in height to heights greater than 2 m was observed. Almost half the individuals that were heavily damaged in 2001 had died by 2008. Heavy elephant utilisation and tree mortality was concentrated in the Sabie thorn thickets ecozone on granites where marula density was highest. Utilisation levels on the surviving individuals throughout the sampled area had almost tripled between 2001 and 2008, with individuals between 5 and 8 m in height accumulating the most additional elephant utilisation. It was concluded that the sampled marula population was not sustaining itself under the conditions prevalent between 2001 and 2008. Since sampled trees >5 m in height were strongly biased towards the Sabie thorn thickets, any projections for the likely fate of marulas in terms of adult mortality would mainly apply to this ecozone. The spatial variability described in this study suggests that further sampling is needed to adequately represent trends elsewhere. [Copyright &y& Elsevier]

1. Understanding the effects of disease is critical to determining appropriate management responses, but estimating those effects in wildlife species is challenging. We used bovine tuberculosis (BTB) in the African buffalo Syncerus caffer population of Kruger National Park, South Africa, as a case study to highlight the issues associated with estimating chronic disease effects in a long-lived host. 2. We used known and radiocollared buffalo, aerial census data, and a natural gradient in pathogen prevalence to investigate if: (i) at the individual level, BTB infection reduces reproduction; (ii) BTB infection increases vulnerability to predation; and (iii) at the population level, increased BTB prevalence causes reduced population growth. 3. There was only a marginal reduction in calving success associated with BTB infection, as indexed by the probability of sighting a known adult female with or without a calf ( P = 0·065). 4. Since 1991, BTB prevalence increased from 27 to 45% in the southern region and from 4 to 28% in the central region of Kruger National Park. The prevalence in the northern regions was only 1·5% in 1998. Buffalo population growth rates, however, were neither statistically different among regions nor declining over time. 5. Lions Panthera leo did not appear to preferentially kill test-positive buffalo. The best (Akaike's Information Criterion corrected for small sample size) AIC c model with BTB as a covariate [exp(β) = 0·49; 95% CI = (0·24–1·02)] suggested that the mortality hazard for positive individuals was no greater than for test-negative individuals. 6. Synthesis and applications. Test accuracy, time-varying disease status, and movement among populations are some of the issues that make the detection of chronic disease impacts challenging. For these reasons, the demographic impacts of bovine tuberculosis in the Kruger National Park remain undetectable despite 6 years of study on known individuals and 40 years of population counts. However, the rainfall and forage conditions during this study were relatively good and the impacts of many chronic diseases may be a non-linear function of environmental conditions such that they are only detectable in stressful periods. [ABSTRACT FROM AUTHOR]

Leopards Panthera pardus have a catholic diet and are generally thought to prey on medium-sized ungulates; however, knowledge on which species are actually preferred and avoided is lacking, along with an understanding of why such preferences arise. Twenty-nine published and four unpublished studies of leopard diet that had relative prey abundance estimates associated with them were analysed from 13 countries in 41 different spatial locations or temporal periods throughout the distribution of the leopard. A Jacobs' index value was calculated for each prey species in each study and the mean of these was then tested against a mean of 0 using t or sign tests for preference or avoidance. Leopards preferentially prey upon species within a weight range of 10–40 kg. Regression plots suggest that the most preferred mass of leopard prey is 25 kg, whereas the mean body mass of significantly preferred prey is 23 kg. Leopards prefer prey within this body mass range, which occur in small herds, in dense habitat and afford the hunter minimal risk of injury during capture. Consequently, impala, bushbuck and common duiker are significantly preferred, with chital likely to also be preferred with a larger sample size from Asian sites. Species outside the preferred weight range are generally avoided, as are species that are restricted to open vegetation or that have sufficient anti-predator strategies. The ratio of mean leopard body mass with that of their preferred prey is less than 1 and may be a reflection of their solitary hunting strategy. This model will allow us to predict the diet of leopards in areas where dietary information is lacking, also providing information to assist wildlife managers and conservation bodies on predator carrying capacity and predator–prey interactions. [ABSTRACT FROM AUTHOR]

Abstract: Tuberculosis, caused by Mycobacterium bovis, was first diagnosed in African buffalo in South Africa''s Kruger National Park in 1990. Over the past 15 years the disease has spread northwards leaving only the most northern buffalo herds unaffected. Evidence suggests that 10 other small and large mammalian species, including large predators, are spillover hosts. Wildlife tuberculosis has also been diagnosed in several adjacent private game reserves and in the Hluhluwe-iMfolozi Park, the third largest game reserve in South Africa. The tuberculosis epidemic has a number of implications, for which the full effect of some might only be seen in the long-term. Potential negative long-term effects on the population dynamics of certain social animal species and the direct threat for the survival of endangered species pose particular problems for wildlife conservationists. On the other hand, the risk of spillover infection to neighboring communal cattle raises concerns about human health at the wildlife–livestock–human interface, not only along the western boundary of Kruger National Park, but also with regards to the joint development of the Greater Limpopo Transfrontier Conservation Area with Zimbabwe and Mozambique. From an economic point of view, wildlife tuberculosis has resulted in national and international trade restrictions for affected species. The lack of diagnostic tools for most species and the absence of an effective vaccine make it currently impossible to contain and control this disease within an infected free-ranging ecosystem. Veterinary researchers and policy-makers have recognized the need to intensify research on this disease and the need to develop tools for control, initially targeting buffalo and lion. [Copyright &y& Elsevier]