Contacts between domestic livestock and wildlife at the Kruger National Park Interface of the Republic of South Africa

One of the most important transboundary animal diseases (TADs) in the southern African region is foot-and-mouth disease (FMD). In this region, a pathway for spread of FMD virus is contacts between cattle and certain species of wildlife. The objective of this study was to evaluate contacts between cattle and wildlife in the Kruger National Park (KNP) and the adjacent Limpopo province for the time periods October 2006 to March 2007 and April to September 2007. In this study, 87 livestock owners and 57 KNP field rangers were interviewed. Fifteen (17%) livestock owners reported contacts between wildlife and cattle. More livestock owners reported observing contacts between cattle and all wildlife species during October-March than April-September (p = 0.012). However, no difference was found between these periods for contacts between cattle and individual wildlife species. A total of 18 (32%) field rangers reported contacts between cattle and wildlife. The most common species-specific contacts were between cattle and buffalo (63/year), cattle and impala (17/year) and cattle and lion (10/year). There were no significant differences in rangers reporting observed contacts between cattle and wildlife during October-March versus April-September or between rangers reporting observed contacts outside versus within the KNP. Overall, there was no evidence of higher contact rates between cattle and wildlife in the study area during October-March compared to April-September. Contact data collected in this study can be used to better understand the transmission of FMD virus in this region.     

Spotted hyaena visitation at anthropogenic sites in the Kruger National Park,South Africa

Many large carnivores are attracted to anthropogenic sites, typically, because they offer easy access to anthropogenic resources, such as garbage. Such behaviour could lead to increased contacts between people and carnivores, with the potential for escalated conflicts. Within protected areas, carnivores experience limited risks of visiting anthropogenic sites. However, conflict could still arise, so that it is important to evaluate the drivers for visitation within protected areas. We tested how age, sex and social rank influenced seasonal visitation rates by spotted hyenas (Crocuta crocuta) at two sites with elevated human activity and infrastructure within the Kruger National Park, South Africa. Social rank did not influence visitation rates, and differences among age classes did not correspond to differences in abilities to procure native food. Instead, juveniles had higher visitation rates than older individuals, but only during the wet season. Visitation rates were not consistently higher during the dry season, nor was there more pronounced differences between age classes in the dry season. Our results suggest the anthropogenic sites were visited as part of exploratory behaviour coupled with occasional rewards. Our study also showed a large individual variation in tendencies towards visiting anthropogenic sites, but only for younger animals. We call for additional studies quantifying individual variation in tendencies to visit anthropogenic sites, and argue that deterrents and limitations in rewards of visiting anthropogenic sites might be efficient in preventing human-hyaena conflict within the Kruger National Park.     

Parasites of South African wildlife. IV. Helminths of kudu, Tragelaphus strepsiceros, in the Kruger National Park

During ongoing surveys of parasites of wild animals in the Kruger National Park, a total of 96 kudu. Tragelaphus strepsiceros, were culled in the southern part of the park at monthly intervals from April 1981 to March 1983. A single kudu was shot in the same area in November 1983. Two more kudu were obtained from Pafuri in the northern part of the Park during October 1981 and another from near Satara in the central part of the Park during October 1982. The helminths of all the kudu were collected and 2 trematode, 4 cestode and 18 nematode species recovered. Amongst the helminths recovered, Agriostomum gorgonis, Cooperia fuelleborni, Cooperia hungi, Cooperia yoshidai, Impalaia tuberculata, a Parabronema sp., a Setaria sp., Strongyloides papillosus, Trichostrongylus falculatus, Schistosoma mattheei, an Avitellina sp., Moniezia benedeni, and Echinococcus sp. larvae appear to be new records for kudu. Haemonchus vegliai, which has been considered a rare nematode, was present in many animals. An amended list of the parasites of kudu is included, and the seasonal abundance of the major nematode species discussed and graphically illustrated.     

Mitochondrial DNA sequence variation in Hippopotamus amphibius from Kruger National Park,Republic of South Africa

Populations of Hippopotamus amphibius have declined throughout Africa in recent years, and are expected to decline further. An understanding of the population genetics of individual populations of hippos is necessary for effective management. To that end, we sequenced a portion of the mitochondrial DNA (mtDNA) control region or D-loop from 37 H. amphibius, from six herds in the central region of Kruger National Park (KNP), Republic of South Africa. We amplified a 453 bp segment by PCR, and identified 21 polymorphic sites and seven haplotypes. All of these haplotypes are private alleles, not found in other populations of hippos from southern Africa. Overall nucleotide diversity (π) was 0.01739, and haplotype diversity (hd) was 0.8273, within the range observed in other parts of Africa. Mismatch analysis conformed more closely to a model of constant population size than either rapid demographic or spatial expansion. An analysis of molecular variance demonstrated no significant differentiation among herds, and Mantel tests showed no significant relationship between geographic and genetic distance among herds separated by up to 47 km (measured as Euclidean [x,y] distance) or 77 km (measured along rivers). Over this range, the population appears to be a single panmictic unit. A test of the hypothesis that calves are more likely to share a mtDNA haplotype with an adult female in the same herd than an adult female from a different herd was not significant.     

The prevalence of Cryptosporidium spp. oocysts in wild mammals in the Kruger National Park, South Africa

This study determined the prevalence of Cryptosporidium spp. oocysts in faecal samples from elephant (Loxodonta africana), buffalo (Syncerus caffer) and impala (Aepyceros melampus) in the Kruger National Park (KNP) and an adjacent game reserve in South Africa. Two of the study areas were in close proximity to rural communities on the western KNP boundary and the third study area was located in the centre of the KNP. Fresh stool samples (n=445) were collected and tested using an immunofluorescent antibody test (IFA) for Cryptosporidium parvum. A total of 278 of these were randomly selected (approximately 90 samples per wildlife species) and tested with the modified Ziehl Neelsen staining technique (ZN) for Cryptosporidium spp. The prevalence of Cryptosporidium spp. was highest in elephants (25.8% [95% confidence interval: 17.3, 35.9]), compared to buffalo (5.5% [1.8, 12.4]) and impala (4.3% [1.2, 10.5]). C. parvum showed similar patterns, being most prevalent in elephants (4.2% [1.5, 8.8]), compared to buffalo (1.4% [0.2, 5.1]) and impala (1.9% [0.4, 5.3]). 29 samples, including ZN positive and IFA positive samples, were retested using a real time PCR (rtPCR) technique. Of the 28 ZN-positive samples, 14 (50%) were positive with rtPCR and of the 9 IFA-positive samples 6 (67%) were confirmed positive by rtPCR. The prevalence of Cryptosporidium oocysts was significantly higher in both of the two study areas adjacent to the western KNP boundary compared to the area in the centre of the KNP (OR=3.2 [1.2, 9.0]; P=0.024). Our study demonstrates for the first time the presence of Cryptosporidium spp. in wildlife in South Africa. The transmission of this parasite between wildlife, domestic animals and humans is a plausible hypothesis and represents a potential risk for immunodeficient human populations.     

Summary of foot-and-mouth disease outbreaks reported in and around the Kruger National Park, South Africa, between 1970 and 2009

Information with regard to foot-and-mouth disease (FMD) outbreaks that occurred in the Kruger National Park (KNP) and adjacent areas of South Africa between 1970 and 2009 was collected from reports and files of various government departments and collated into one report. The collected data were summarised in a table and assessed for patterns. Fifty-one FMD outbreaks occurred during this period in the target area, of which 16 were SAT 1, 31 were SAT 2,4 were SAT 3 and 3 were not serotyped. No pattern could be discerned although SAT 1 outbreaks occurred more frequently in the summer months while more SAT 2 outbreaks occurred in winter.     

The epidemiology of tuberculosis in free-ranging African buffalo (Syncerus caffer) in the Kruger National Park, South Africa

The presence of bovine tuberculosis (Mycobacterium bovis) in the Kruger National Park (KNP) was determined for the first time in 1990. It was diagnosed in an African buffalo (Syncerus caffer) bull, which was found recumbent and in an emaciated and moribund state near the south-western boundary fence. This prompted an investigation into the bovine tuberculosis (BTB) status of the KNP, with emphasis on its epidemiological determinants and risk factors. This report documents the findings of surveys that were conducted from 1990 to 1996. It was found that BTB had entered the KNP ecosystem relatively recently (+/- 1960), and has found favourable circumstances for survival and propagation in a fully susceptible and immunologically naive buffalo population. Indications are that it entered the KNP from across the southern river boundary, where the presence of infected domestic cattle herds had been documented. From there the infection spread through the southern buffalo population and is currently spreading in a northward direction. It was estimated that this northward spread took place at a rate of about 6 km per year; the prospect being that, if this rate of spread is maintained, the entire KNP may be affected in less than 30 years from now. Spillover from buffalo had already occurred in species such as chacma baboon (Papio ursinus), lion (Panthera leo), cheetah (Acinonyx jubatus), kudu (Tragelaphus strepsiceros) and leopard (Panthera pardus). Although there is no indication yet that these species act as maintenance hosts, the possibility is raised that these, or an as yet overlooked species, might assume such a role in future. In the KNP, BTB manifests itself as a chronic and predominantly subclinical disease in buffalo. It may take years for clinical signs to develop, and then only at a terminal stage, when emaciation is a constant feature. It is suspected that the time from infection to death is variable and dependent on the animal's immune response, which can be weakened by such factors as stress, old age or droughts. It was found that, in the interim, buffalo have a normal reproductive life. On necropsy, buffalo show almost exclusively lung and upper respiratory tract involvement, pointing to an aerogenous mode of transmission. Histologically, little sign of encapsulation of lesions was detected, which suggests that they are exceptionally susceptible to BTB and that most lesions are open and infectious and progressive, leading ultimately to death of the individual. Evidence also indicates that BTB is progressive within the herd context (92% being the highest prevalence rate thus far determined in a buffalo herd) as well as progressive within the KNP buffalo population (the implication being that virtually all buffalo herds in the KNP will eventually be infected). Preliminary data suggest a positive correlation between disease prevalence and mortality, with potential mortality reaching up to 10% in buffalo herds having BTB prevalence rates of 50 % and higher. Only the future will tell what the effect of the disease on the population dynamics of buffalo will be.     

Mediorhynchus gallinarum (Acanthocephala: Gigantorhynchidae) in Helmeted guineafowls, Numida meleagris, in the Kruger National Park, South Africa

Mediorhynchus gallinarum was recovered from the small intestines of 36 of 50 Helmeted guineafowls sampled from August 1988 to May 1989. The intensity of infection ranged from 1-141 worms per host, with a mean intensity of 23.2 (+/- 34) and a median intensity of 5. The Wilcoxon-Mann-Whitney test revealed no significant differences between the mean worm burdens of male and female birds at the 5% level (P > 0.05). Slightly more female than male acanthocephalans were collected. The majority (63.4%) of females had eggs with fully-developed embryos, 9% had immature eggs, 21.2% had no eggs and the egg status of 6.4% could not be determined. No seasonal pattern of intensity of infection emerged from the data, but worm burdens were markedly higher after good rains in February 1989. South Africa constitutes a new geographic record for M. gallinarum.     

Coccidian oocyst and nematode egg counts of free-ranging African buffalo (Syncerus caffer) in the Kruger National Park, South Africa

Faecal specimens collected in the Kruger National Park from 103 African buffaloes (Syncerus caffer) up to 1 year old and 283 buffaloes older than 1 year were examined for the presence of coccidian oocysts and nematode eggs. Most specimens from animals older than 1 year had negative coccidian oocyst counts. Positive specimens from younger animals had significantly higher coccidian oocyst counts than those from older animals. No such difference was found for nematode egg counts.     

Parasites of domestic and wild animals in South Africa. XLI. Arthropod parasites of impalas,Aepyceros melampus,in the Kruger National Park

Ectoparasites were collected from impalas, Aepyceros melampus, at four localities within the Kruger National Park, namely Skukuza, in the Biyamiti region, Crocodile Bridge and Pafuri. Animals were also examined at Skukuza during a severe drought and at Skukuza and Pafuri towards the end of a second drought. Parasite burdens were analysed in relation to locality, sex, age class, month and drought. The impalas were infested with 13 ixodid ticks species, including two that were identified only to genus level. Except for four animals at Pafuri, all were infested with Amblyomma hebraeum. The highest intensity of infestation with larvae of this tick occurred from April to June and during November and December at Skukuza and in the Biyamiti region. Infestation with nymphs was highest during late winter. All animals were infested with Boophilus decoloratus, and the intensity of infestation was highest during spring. The intensity of infestation with Rhipicephalus appendiculatus was highest at Crocodile Bridge and at Pafuri, and that of Rhipicephalus zambeziensis at Skukuza. With both the latter species the intensity of infestation of larvae was highest from April to August, of nymphs from July to September or October and of adults during February and March. Rhipicephalus kochi was present only at Pafuri. The impalas also harboured five louse species and two species of hippoboscid flies. The intensity of infestation with lice tended to be greater during late winter and spring than during other seasons and greater on lambs than on yearlings on which it was greater than on adult animals.     

Feeding habits and flight range of blow-flies (Chrysomyia spp.) in relation to anthrax transmission in the Kruger National Park, South Africa

Carrion-frequenting blow-flies (Chrysomyia albiceps and C. marginalis) were allowed 4 days of feeding on 32P-orthophosphate-labelled blood or an impala carcass (Aepyceros melampus) in the northern Kruger National Park, South Africa. The dispersal and density of fly faecal and discard droplets were then established using a Geiger-Counter, indicating that most droplets occurred between a height of 1 and 3 m on nearby leaves and twigs. This coincides with the preferred feeding height of kudu (Tragelaphus strepsiceros). During a previous anthrax epizootic kudu comprised 73.15% of a total medium to large mammal mortality figure of 1054. Further analysis of mortality shows browsers to have been most severely affected, and it is suggested that this is correlated with feeding habits of these animals. Trapping also yielded radioactively labelled C. albiceps up to 32.5 km and C. marginalis up to 25 km from the isotope source.     

Influence of dipping practices on the seroprevalence of babesiosis and anaplasmosis in the foot-and-mouth disease buffer zone adjoining the Kruger National Park in South Africa

A serological survey of bovine babesiosis and anaplasmosis was conducted in the foot-and-mouth disease buffer zone surrounding the Kruger National Park in South Africa between 2001 and 2003 to determine whether the withdrawal of government-subsidized dipping in certain regions had affected the seroprevalence of these tick-borne diseases. Seroprevalence of Anaplasma marginale and Babesia bovis increased during the study period. This increase was greater in Limpopo Province where farmers had to supply their own acaricide than in Mpumalanga Province where dipping materials were provided by the local Veterinary Services. The number of animals testing positive for B. bigemina decreased in both provinces during the study period, which was attributed to possible vector displacement rather than more effective tick control measures. Responses to a questionnaire on ticks and tick-borne diseases revealed local knowledge on the subject to be highly variable and sometimes incorrect.     

The long-term effect of fire and grazing by wildlife on range condition in moist and arid savannas in the Kruger National Park

Few assessments of the effects of fire and grazing on the herbaceous components of savannas have been reported for Africa. In the Kruger National Park, South Africa, range condition was monitored at three savanna sites spanning a rainfall gradient of 450 to 700 mm and subject to grazing by wildlife. The sites were burnt at 1-, 2- and 3-year intervals, in different seasons and included a control treatment excluding fire for >40 years. Initial surveys of the herbaceous vegetation were conducted between 1954 and 1957 and repeated between 1998 and 2001. Grass species were categorised as either decreaser or increaser species, which decline or increase with over- or under-utilisation, respectively, and their potential to provide forage and fuel for fires indicative of range condition were derived. Range condition improved with regular burning in the moist sites, but deteriorated in the arid sites over all seasons and frequencies of burning. It is concluded that the current homogenous approach to burning across the Park needs to be adapted by reducing the frequency of fires at more arid sites and can be achieved by burning according to the proportions of decreaser and increaser species reflecting the ecological status of the herbaceous vegetation.     

Afrotropical Culicoides: a redescription of C. (Avaritia) kanagai Khamala & Kettle, 1971, reared from elephant dung in the Kruger National Park, South Africa

The discovery of Culicoides kanagai in South Africa represents a new record for this species. The female is redescribed, and the male is described for the first time. Culicoides (A.) dasyops Clastrier, 1958 is shown to be closely related to it but C. (A.) alticola is only superficially related. Short notes on the larval habitat of C. kanagai, the dung of the African elephant, Loxodonta africana, are given. The dung of both the white rhinoceros, Ceratotherium simum, and the black rhinoceros, Diceros bicornis, is considered to be a possible alternative site for the immatures of C. kanagai.     

A survey of annoyance of livestock by Simulium chutteri Lewis along the Orange River, South Africa (Diptera: Simuliidae)

A survey by means of questionnaires was conducted along the Orange River to determine the extent of blackfly annoyance to livestock during 1984-1988. Severe annoyance reached peaks during September-November and increased over the years. Annoyance levels decreased with distance from the river with occasional severe annoyance as far away as 76 km. Annoyance levels increased with distance downstream from the P. K. le Roux dam to Augrabies (750 km). Greater water releases for increased irrigation and electricity generation may be an important reason for the higher annoyance levels. Present day high and increasing irrigation water requirements and the great length of the river probably render control by water level fluctuations impractical. Loss of condition of especially small livestock is the main consequence of annoyance by female blackflies. Decreased percentage lambing and occasional deaths were also reported.     

The biochemical, morphological and virulence profiles of Bacillus anthracis isolated in the Kruger National Park

The biochemical, morphological and virulence profiles of 44 Bacillus anthracis isolates, obtained from various localities and carcass remains of wild animals in the Kruger National Park, South Africa, were examined. The morphological characteristics tested for included: the formation of capsules on bicarbonate agar, the motility of the vegetative organism, the presence of haemolysis on blood tryptose agar, the sensitivity of the vegetative organism to bacteriophage, the production of lecithinase on egg yolk agar, the liquefaction (hydrolysis) of gelatine and the capability of each isolate to produce mucoid colonies when grown on bicarbonate agar with horse serum in an atmosphere containing CO2. The API 50CHB and 20E systems were used to evaluate the biochemical activity of each isolate. The virulence of each isolate was determined by its LD50, using an inbred line of Balb/C mice. A clear pattern in the biochemical reactions emerged that appeared to be specific for each isolate. On the API 50CHB test strip, only 2 of the 44 isolates gave a 100% positive reaction to all 10 of the biochemical substances to which it was supposed to react, 9 gave positive results to 90%, 19 were positive to 80%, and 14 were positive to 70%. The reactions on the API 20E were completely different from what was expected, with only 1 of the biochemical activities (gelatinase production) showing a positive reaction to all the isolates. The virulence test indicated that 27/44 isolates could be regarded as highly virulent with a LD50 of less than 1,000 organisms, and the rest of the isolates as virulent with a LD 50 of 1,001-10,000 organisms.(ABSTRACT TRUNCATED AT 250 WORDS)