Copper poisoning in wild ruminants in the Kruger National Park: geobotanical and environmental investigation.

A geobotanical and environmental investigation was undertaken to investigate the potential for copper poisoning in wild ruminants within the Phalaborwa area in the Kruger National Park and to confirm that environmental copper pollution associated with smelting operations at a nearby mine was the source of copper responsible for the poisoning. The study area selected was divided into high, moderate and low-risk zones and a control area based on initial topsoil copper concentrations and impala (Aepyceros melampus) liver copper concentrations in relation to distance from the copper smelter. Samples collected revealed that topsoil copper concentrations were significantly higher than subsoil copper concentrations at the same sites. There was a significant linear decrease in topsoil to subsoil copper concentration relative to distance from the copper smelter and thus from the high-risk zone to the control area. Copper concentrations of unwashed plant material were significantly higher than washed plant material at the same sites, indicating the deposition of copper on the plant surfaces. Copper deposits in dust fall buckets were significantly higher downwind than upwind from the smelter stack and the presence of atmospheric copper was also confirmed with the aid of low-volume air sampling monitors. The investigation confirmed that the emissions from the copper smelter were sufficient in amount and appropriate in direction to have contributed significantly to the topsoil copper concentrations, unwashed plant copper concentrations and dust fall results.     

Fire behaviour in the Kruger National Park

Abstract

Fire research in the Kruger National Park has largely been focussed on the effect of the season and frequency of burning on the vegetation. Very little information is available on the effect of fire behaviour and in particular fire intensity, on the flora of the Park. Consequently a research project was conducted to develop statistical models for predicting fire intensity, flame height and rate of spread in the field. The devleopment of these models constitutes the initial phase of determining the relationship between fire behaviour and vegetation response.     

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.     

Drag-sampling of free-living ixodid ticks in the Kruger National Park

Free-living ticks were collected by means of drag-sampling in 32 of the 35 landscape zones of the Kruger National Park during a period of 1 calendar month. Of the 18,199 specimens collected, 99.53% were larvae, 0.05% nymphs and 0.42% adults. Fourteen species were collected. Amblyomma hebraeum followed by Boophilus decoloratus, predominated, both in distribution and abundance. Large variations were encountered between drags. There was no correlation between the numbers of larvae collected and time of day, temperature, grass length, vegetation biomass estimates and subzone type.     

Cowdria ruminantium infection in ticks in the Kruger National Park.

Adult Amblyomma hebraeum ticks, the principle vector of heartwater (cowdriosis) of domestic ruminants in southern Africa, were collected in pheromone traps placed in Kruger National Park, an exclusively wildlife sanctuary in South Africa. These ticks transmitted Cowdria ruminantium, the rickettsial agent causing heartwater, to a susceptible goat, resulting in acute, fatal disease. C ruminantium was isolated in bovine endothelial cell culture from the plasma of this animal during the febrile stage of the disease and transmitted to susceptible goats, causing fatal heartwater. The prevalence of C ruminantium infection in 292 ticks was determined by polymerase chain reaction (PCR) analysis to be 1.7 per cent (95 per cent confidence interval 0.71 to 4.0 per cent). A DNA probe analysis, which is less sensitive than PCR, detected infection in three of the five PCR-positive ticks. The remaining infections were below the detection limit of the DNA probe, which is approximately 70,000 organisms. This is the first evidence that a vector-wildlife cycle of transmission of C ruminantium can be maintained independently of domestic ruminants.     

The Reproductive Seasons of Some Mammals in the Kruger National Park

During a study on the presence and location of Meloidogyne incognita race 2 within maize roots, a nematode-trapping fungus, Arthrobotrys dactyloides was observed for the first time on maize in South Africa.     

Bone-collecting habits of spotted hyaenas Crocuta crocuta in the Kruger National Park

An examination of 18 Crocuta crocuta dens in the Kruger National Park, showed that this species can be responsible for bone assemblages at dens, more so at permanent sites such as granite or calcrete caves than at temporarily occupied aardvark holes or road culverts. Because of the facultative nature of food-transporting behaviour, the rate at which bones are accumulated at dens varies, ranging from no bones collected to nine food items collected per month. The relative abundance of ungulate species represented in the large assemblages resembles that of ungulates living in the region surrounding a den.     

Tuberculosis in kudus (Tragelaphus strepsiceros) in the Kruger National Park.

Five kudus (Tragelaphus strepsiceros), three bulls and two cows, within the Greater Kruger National Park complex, were diagnosed with generalized tuberculosis caused by Mycobacterium bovis. The lesions seen in these animals were similar to those previously reported in kudus and included severe tuberculous lymphadenitis of the nodes of the head and neck (that resulted in noticeable uni- or bilateral swelling beneath the ear), thorax, and the mesentery. All the animals also suffered from severe granulomatous pneumonia. The lesions in the lungs were more severe cranially and had a miliary distribution elsewhere in the lungs. Based on the DNA patterns of the M. bovis isolates, at least some of these kudus were infected with strains commonly present in tuberculous buffaloes, lions, cheetahs, and baboons in the Park whereas other strains from these kudus were quite different and may reflect another source of infection. The presence of tuberculous kudus in the Park is expected to complicate control measures that may be instituted to contain or eradicate the disease in the Park.     

The tegument of Schistosoma hippopotami from Hippopotamus amphibius in the Kruger National Park

Schistosoma hippopotami were collected from the right heart chambers and pulmonary arteries of Hippopotamus amphibius culled in the Kruger National Park. The schistosomes were subjected to scanning electron microscopy as well as optical microscopy. The results indicate that S. hippopotami is not conspecific to S. mansoni as suggested in the literature. On account of the morphology of certain tegumental structures of both male and female parasites, it is suggested that S. hippopotami is adapted to the pulmonary arterial circulation of its host.     

Seasonal abundance of carrion-frequenting blow-flies (Diptera: Calliphoridae) in the Kruger National Park

Monthly population fluctuations of carrion-frequenting blow-flies over a 24-month period were monitored using 2 carrion-baited traps in the southern Kruger National Park (KNP) and 3 in the northern KNP. All species displayed a clear seasonality. Chrysomyia marginalis and Chrysomyia albiceps were by far the most abundant. C. marginalis attained maximum abundance between November and March, with relatively low numbers present between May and September. C. albiceps maintained high population numbers between January and March in the northern KNP, with minimum numbers between May and August. In the southern KNP, C. albiceps became abundant from November to February, with low population levels between April and September. Although present only in relative low numbers, populations of Lucilia cuprina showed a clear increase in winter. Chrysomyia chloropyga, Chrysomyia putoria and Chrysomyia bezziana were trapped in significant numbers in the southern KNP, the latter 2 species reaching relative abundance in the warmer months, whereas C. chloropyga increased in cooler months from June to September. Graphic illustrations of monthly abundance are provided for all species.     

Estimating grass fuel loads with a disc pasture meter in the Kruger National Park

Abstract

The major portion of the fuel load in the savanna areas comprises surface fuels in the form of the standing grass sward. The disc pasture meter was successfully calibrated for estimating grass fuel loads in the main landscapes of the Kruger National Park. The calibration comprised estimating the mean disc height of a 4 m² quadrat and harvesting the grass as close to ground level as possible. Using a large quadrat gave highly satisfactory results indicating that this procedure should be considered as a standard method of calibration, particularly in grass swards having a low basal cover.     

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.     

The antibiotic sensitivity patterns of Bacillus anthracis isolated from the Kruger National Park

Forty-four isolates of Bacillus anthracis made from carcasses and soil in different localities of an endemic anthrax area in the Kruger National Park, South Africa, were tested by standard disc diffusion for their susceptibility to 18 different antibiotics. These were ampicillin, penicillin G, sulphatriad, streptomycin, clindamycin, gentamicin, fusidic acid, trimethoprim, sulphamethoxazole, chloramphenicol, erythromycin, methicillin, tetracycline (2 different concentrations), novobiocin, cefotaxime, netilmicin, cefamandole and cefoxitin. All the isolates were susceptible to ampicillin, streptomycin, chloramphenicol, erythromycin, tetracycline, methicillin and netilmicin. More than 90% of the isolates were sensitive to clindamycin, gentamicin and cefoxitin, whereas only 84.1% of the isolates were sensitive to penicillin G, 86.4% to novobiocin and 68.18% to cefamandole. Complete resistance in 100% of the isolates was encountered with trimethoprim and sulphamethoxazole, with 95.45% for sulphatriad. Moderate sensitivity occurred with penicillin G (15.9% of the isolates), clindamycin (6.8%), novobiocin (13.6%), fusidic acid (84.1%), cefotaxime (100%), cefamandole (31.8%) and cefoxitin (6.8%). The relevance of the findings to the therapeutic uses of different types of antibiotic in human clinical cases referred to in the literature is discussed.     

Territorial Behaviour of the Tsessebe (Damaliscus Lunatus Lunatus Burchell) in the Kruger National Park

This paper forms part of a general bio-ecological study of the tsessebe (Damaliscus lunatus lunatus Burchell) presently being undertaken in the Kruger National Park. Territorial demarcation and maintenance is achieved by various ritualized displays and marking techniques. Territory marking includes both visual and olfactory methods. Agonistic behaviour is evidenced by dominance and threat displays while territorial conflicts may result in actual fighting. The various behavioural patterns relating to territoriality are discussed with an evaluation of their possible significance in the social organisation of the species.     

Timing of breeding of the redbilled oxpecker (buphagus erythrorhynchus) in the Kruger National Park

The reproductive activity of the redbilled oxpecker Buphagus erythrorhynchus is governed primarily by the effects of rainfall and the onset of the laying cycle is dependent on the time of year at which the rain occurs. At the onset of the rainy season in August or early September the biomass of the Ixodldae increases on the mammalian symbionts and is made use of for feather synthesis during moult. During October with a significant increase in the biomass of Tabanidae it is possible to accumulate a large enough protein reserve to initiate breeding.