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Barbara Paterson, Chris J. Brown, Greg Stuart-Hill, Heike Winschiers, Les G. Underhill, Tim T. Dunne, Britta Schinzel, Ben Beytell, Fanuel Demas, Pauline Lindeque, Chris Weaver
We present a method for developing a knowledge base to give wildlife managers timely access to pertinent information. This knowledge-based approach to species management in Namibia focuses on anthologies and management strategies for high-value mammal species. To manage wildlife resources sustainably access to an appropriate knowledge base is essential. The strategic species management approach promotes planning on local, national, and international levels. A hypermedia Information System for Rare Species Management (IRAS) and a decision support system (Wildlife Introduction Advisor) are described. Unlike print media, which become dated, hypermedia is easily updated. The non-sequential nature of hypermedia allows information extraction according to the readers needs. Due to this flexibility hypermedia supports adaptive management and information sharing. Usability evaluation of the IRAS system disproved our assumption that established wildlife conservation categories such as habitat, distribution, and numbers are appropriate and sufficient to structure species information. This result led to a restructuring of the information according to management objectives. Evaluation of the Wildlife Introduction Advisor indicates that the model performs reliably and is robust towards input error. Human experts seem to be susceptible to bias. The economic benefits associated with wildlife translocations demand accountability through a well-defined, transparent distribution process. In Namibia this demand is achieved through the use of a knowledge-based decision support tool.
The influence of gender on the physical and chemical properties of the M. longissimus dorsi et lumborum of mountain reedbuck (Redunca fulvorufula) was examined. The mean live weights of ten male (28.58 kg) and nineteen female (30.58 kg) mountain reedbuck did not differ (P > 0.05),and the mean cold carcass weight was 16.36 kg for both genders. Gender had no influence (P > 0.05) on any of the physical characteristics (pH, drip loss, cooking loss, shear force, colour) investigated. For the proximate chemical analysis of the M. longissimus dorsi et lumborum muscle, the effect of gender was only significant for the protein content, where the females (24.51%) displayed a higher percentage of protein compared to the males (23.68%). Neither the amino acid nor the mineral content differed significantly between the two genders. Glutamic acid (11.35 g/100 g) was the most abundant amino acid, followed by aspartic acid (2.94 g/100 g), glycine (0.86 g/100 g) and serine (0.66 g/100 g). The mineral content of mountain reedbuck indicated that meat derived from this species is high in phosphorus (206.47 mg/100 g), high in iron (4.19 mg/100 g), a source of zinc (1.80 mg/100 g), and low in sodium (4.19 mg/100 g). No significant differences between the genders for total saturated fatty acids (38.09%), total mono-unsaturated fatty acids (18.04%) or total polyunsaturated fatty acids (43.74%) were noted. The mean polyunsaturated:saturated fatty acid ratio for mountain reedbuck was 1.15 and the mean n-6:n-3 PUFA ratio 2.08. The extent of the influence of gender on physical and chemical characteristics of meat was found to be of limited practical value.
A database of approximately 9000 trophy measurements of ungulates hunted in South Africa between 1993 and 2001 was analysed in order to detect species-specific,regional variation in mean trophy quality. Blesbok (Damaliscus dorcas), eland (Taurotragus oryx), impala (Aepyceros melampus), kudu (Tragelaphus strepsiceros), mountain reedbuck (Redunca fulvorufula) and springbok (Antidorcas marsupialis) showed statistically significant variation in trophy quality. A number of other species including blue wildebeest (Connochaetus taurinus), black wildebeest (Connochaetus gnou), bushbuck (Tragelaphus angusticeps), common reedbuck (Redunca redunca), gemsbok (Oryx gazella), red hartebeest (Alcelaphus buselaphus), nyala (Tragelaphus angasii) and waterbuck (Kobus ellipsiprymnus) were insignificant. The manipulation of trophy quality on ranches is speculated to be the major cause of these significant regional variations. It is recommended that species-specific baselines of trophy quality and associated levels of ‘acceptable manipulation’ be established and incorporated into a national trophy quality monitoring programme to provide some level of protection to an industry that contributes significantly to the South African economy.
Two species of common, co-occurring southern African fruit bats, Epomophorus wahlbergi and E. crypturus, are difficult to distinguish in the field. The main character used to distinguish them is the arrangement of palatal ridges (two behind last molar in E. crypturus, one in E. wahlbergi); this character is difficult to see in the field and unreliable in juvenile skulls. Many workers have commented on the more slender and elongated shape of the muzzle of E. crypturus compared with E. wahlbergi. We test the usefulness of this character by comparing skull length and maxillary length and width in 51 skulls in museum collections representing both species. Our data revealed broad overlap in skull length between species (reflected in overall body size overlap), but (after allowing for age-related variation) complete separation of the sexes by maxillary length (males >21.5 mm; females <21.5 mm) and skull length (males >52 mm; females <52 mm) and complete separation of species by maxillary width (E. wahlbergi >13 mm for females and >14 mm for males; E. crypturus <13 mm for females and <14 mm for males). We discuss field characters that may permit species diagnosis based on maxilla shape, as well as acoustic characters.
Chonopeltis australis is an ectoparasite of freshwater fishes and is endemic to Africa. It was collected in Boskop Dam in the North West Province from Labeo capensis and Labeo umbratus. Its prevalence on L. umbratus was always higher than 75%, but varied between 25% and 100% on L. capensis. Furthermore, L. umbratus carried a mean of between 2.4 and 5.5 (mean 3.3) parasites compared with 0.3 to 3.5 (mean 2.5) on L. capensis, indicating that L. umbratus is the preferred host. The parasites were more frequently attached to the unossified brim of the operculum, and larger hosts were more frequently and more intensely parasitized than smaller hosts. The distribution of this parasite species is limited to the Vaal River. Stage V larvae were observed, interspersed between adult specimens. This information is compared to information from other genera in this taxon.
Concern about the habitat requirements of sable antelope (Hippotragus niger) has increased due to population declines shown in some protected areas. Our study was prompted by the lack of initial increase by the sable antelope introduced into the Pilanesberg Game Reserve in North West Province, South Africa; 67 animals released between 1979 and 1983 had only grown to approximately 70 animals by 1988. We recorded forage selection by sable antelope within the context of the landscape units favoured in different seasons. Chrysopogon serrulatus, Panicum maximum, Heteropogon contortus, and Themeda triandra contributed most to the diet of sable antelope. Faecal crude protein content did not drop below 6.6% of dry matter during the dry season, with use of burnt grassland by sable contributing to an elevation in faecal protein levels at the beginning of the wet season. The sable population had increased to 127 animals by 1991, suggesting that the earlier lack of population growth had been due to below-average rainfall, lack of burns providing green regrowth during the dry season, or a delay in learning to exploit available forage resources efficiently.
Here we studied the the diet and habitat use of buffalo (Syncerus caffer caffer) on Doornkloof Nature Reserve (DNR) in the Nama-Karoo, South Africa. The buffalo were predominantly grazers. Only seven grass species formed the bulk of their diet and marked seasonal shifts were observed in the contribution of these species to the diet of buffalo. Eragrostis lehmanniana and Sporobolus fimbriatus formed most of the food eaten in the wet seasons but contributed little to the diet in the dry season. By contrast, T. triandra contributed little to the diet in the wet seasons but formed the bulk of the diet in the dry season. This pattern appears to be related to the distribution of and to the seasonal changes in the acceptability of these grass species to buffalo. In the wet seasons the buffalo mainly foraged in the lowland habitats adjacent to riverine thickets containing E. lehmanniana and S. fimbriatus which were favoured by buffalo at this time. This pattern changed in the dry season when the buffalo ranged further from the cover of the riverine thicket and moved through the lowland habitats into the upland habitats where Themeda triandra, which was favoured in the dry season, was abundant. The favourable nitrogen and phosphorus concentrations recorded in buffalo feacal samples on DNR suggests that buffalo are likely to perform well in this environment and the population growth appears to confirm this.
Electric fencing is increasingly used as a tool for elephant (Loxodonta africana) conservation in human-dominated landscapes and there are few empirical studies to demonstrate that electrified barriers are effective in deterring elephants from raiding crops. The factors determining the effectiveness of electric fences are not fully understood. We assessed the performance of Namelok and Kimana fences in reducing human–elephant conflict by comparing the frequency of crop-raiding by elephants and the perceptions of farmers on the effect of the fences in reducing elephant crop-raiding within fenced and adjacent unfenced farmlands. We also examined the effect of intact fence wires, presence of current and amount of voltage on fence breakage by elephants. Electric fencing reduced elephant crop-raiding and other forms of human–elephant conflicts. Namelok fence was not broken by elephants whereas Kimana fence was broken several times probably because it borders Kimana Sanctuary which provided cover where elephants could retreat after crop-raiding. The mere presence of current did not minimize fence breakage by elephants. Elephants entered fenced areas more frequently when the fence wires were broken than when wires were intact. Our results suggest that, location of fences in relation to landscape factors, maintenance of effective non-electrified fences and proximity of fences to areas of high elephant concentration are significant determinants of fence performance in mitigating elephant crop-raiding.
In order to accurately assess the status of the cheetah Acinonyx jubatus it is necessary to obtain data on numbers and demographic trends. However, cheetahs are notoriously difficult to survey because they occur at very low population densities and are often shy and elusive. In South Africa the problem is further complicated in areas where land is privately owned, restricting access, with dense bush and cheetahs that are frequently persecuted. Cheetahs are individually identifiable by their unique spot patterns, making them ideal candidates for capture–recapture surveys. Photographs of cheetahs were obtained using four camera traps placed successively at a total of 12 trap locations in areas of known cheetah activity within a 300 km2 area in the Thabazimbi district of the Limpopo Province. During 10 trapping periods, five different cheetahs were photographed. These results were used to generate capture histories for each cheetah and the data were analysed using the capture–recapture software package CAPTURE. Closure tests indicated that the population was closed (P = 0.056). The Mh model was used to deal with possible heterogeneous capture probabilities among individual cheetahs. Closure tests did not reject the model assumption of population closure (P = 0.056). The Mh model produced a capture probability of 0.17 with an estimate of 6–14 cheetahs (P = 0.95) and a mean population size of seven cheetahs (S.E. = 1.93). These results are promising and will be improved with employment of more camera traps and sampling a larger area.
The prey selection and predatory behaviour of a single pride of lions (Panthera leo) was studied in the 8500 ha Karongwe Game Reserve from 1999–2005. The study focused on the difference between prey selection in the first three years when a two-male coalition was present with a similar period thereafter when one of the males was removed and subadult males dispersed from the pride. A total of 662 kills were recorded, with blue wildebeest (Connochaetes taurinus), warthog (Phacochoerus africanus), waterbuck (Kobus ellipsiprymnus), zebra (Equus burchelli) and impala (Aepyceros melampus) being the most preferred species. Although there was preference for these species, and adult prey were favoured, there was no significant selection for prey size, age or gender. There was a significant difference in the number of kills made when the two-male coalition was present as opposed to the single pride male. The solitary pride male spent significantly more time with the females and shared most of their kills, and during this period dispersing subadult males killed a substantial amount of prey when separated from the pride. Knowledge on predator feeding behaviour is important for managers to assess impact on prey populations in small reserves in order to manage them correctly, thereby preventing depletion of such populations.
As predicted, based on the limitation of food quality for small body size ruminants, the Cape grysbok (Raphicerus melanotis) is a selective browser, with relatively few plant species eaten. The alien Australian acacia (Acacia cyclops) is, however, prominent in their diet at this study site. We suggest that the grysbok's use of this alien species and the lack of their population response to clearing of acacias shows that they are able to switch diets as resources change.
The nutritional status of springbok, Antidorcas marsupialis, in the Kalahari was assessed in four habitats and three seasons by means of faecal profiling. Habitat only had a significant effect on the faecal nitrogen concentration in the cold–dry season, whereas faecal phosphorus concentrations showed no significant differences across habitats within a season. Seasonal differences in faecal nitrogen and phosphorus concentrations were more pronounced than habitat differences. Both faecal nitrogen and phosphorus concentrations differed significantly seasonally in the Nossob riverbed and in the dunes. Faecal concentrations of phosphorus and nitrogen were similar to that of springbok in other areas, but faecal nitrogen and phosphorus were below the critical range during the cold–dry season in the dune habitat and at a critically low level in the Nossob riverbed. Springbok in the southwestern Kalahari may experience nutritional stress during the dry winter period, especially in the interior dune fields.
This study was conducted to determine the diet of helmeted guineafowl (Numida meleagris) in the Riemland and to establish the effects that these gamebirds may be having on cash crop yield. In the Riemland farming community many farmers complain of harvest losses suffered to guineafowl. It was found that the main dietary items during all seasons are corms of weed plants, primarily Cyperus spp. Helmeted guineafowl rely to a large degree on waste maize and germinating wheat during winter when natural food is difficult to find. Although they do not pose any problems with regard to maize farming, this is not necessarily true for wheat farming.
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