Academic literature on the topic 'Black-backed jackal – South Africa – Eastern Cape'

SUMMARYRabies is a prevalent and re-emerging disease in South Africa particularly in rural areas with high human densities. Outbreaks are frequently reported in the north and eastern parts of this country, probably an indication of inadequacy in the control of the disease. Following the 2005/2006 outbreak in Limpopo, we undertook an analysis of case surveillance data and genetically characterized 18 rabies viruses, all recovered from domestic dogs. Although rabies prevalence gradually declined annually from 2007, dog rabies still remains a public and veterinary health hazard in this region. Sylvatic rabies cycles are maintained by the black-backed jackal species in specific ecological conditions in the northwest of the province (Waterberg area), unlike in the north and east (Vhembe and Mopani districts, respectively), where spillover of infection between dogs and jackals is likely to predominate. Genetic analysis demonstrated that the rabies virus strain currently circulating within dog populations in Limpopo province is the same variant responsible for the 2005/2006 rabies outbreak. However, residual foci probably exist hence the observed sporadic outbreaks. These data further underline the value of continuous and sustainable dog immunization in controlling rabies.

The black-backed jackal (Canis mesomelas) and the caracal (Felis caracal) are considered by most farmers in the Eastern Cape to be responsible for excessive livestock losses (sheep and goats) and are, as such, hunted extensively within the Province. Stomach content analyses of individuals killed during predator control operations indicate that caracal are opportunistic hunters of small to medium-sized mammals, preying predominantly on antelope within farmland. Black-backed jackal are opportunistic omnivores, preying predominantly on livestock and antelope in farmland, while invertebrates and antelope constitute the major food items within a game reserve. The diet of caracal was found to be largely influenced by the age of individual animals with old and young animals being the predominant killers of livestock, whereas black-backed jackal diet is influenced primarily by the social structure exhibited by the species, with male animals exhibiting a marked summer peak in livestock killing, due to the increased energetic demands of parental care associated with a long term pair bond. Two caracal (a sub-adult male and adult female), were radio-tracked within farmland for a total of twelve months, yielding the smallest recorded homerange sizes for the species to date (2.1km² and 1.3km² respectively). No livestock losses were recorded within these homeranges for the duration of the study. These data suggest a relatively high abundance of caracal within Lower Albany and further illustrate that individual animals are capable of preying solely on natural prey species over an extended period, when occurring within livestock farming areas. The analysis of local hunt club records and questionnaires revealed a higher incidence of local black-backed jackal (15.2 PD/Kill), than caracal (34.7 PD/Kill), with a marked seasonal peak in kills, for both species, occurring during summer months. The use of hound packs was found to be more effective in reducing the overall abundance of caracal than black-backed jackal, as this technique was seen to eliminate more adult female caracal than black-backed jackal, during the respective breeding season of each species. Local hunt club owners and farmers were more accurate in identifying problem black-backed jackal (74%), than caracal (59%). Recommendations are presented for minimizing stock losses through the application of selective control of specific problem animals, the use of various control measures and encouraging natural prey abundance.

Mammalian predators are keystone species and can have disproportionately large impacts, relative to their abundance, on the communities and ecosystems they inhabit. In addition, predator-prey interactions (including bottom-up and top-down effects) are the fundamental linkage among species in food webs. Thus, understanding the food requirements of predators is imperative. There have been no comprehensive studies on the diet of black-backed jackals (Canis mesomelas) across a full seasonal cycle in the Albany Thicket Biome of the Eastern Cape Province. This biome is rich in plant diversity, is highly nutritious for herbivores and supports a large number of mammalian species, yet it is poorly conserved. The aim of the present study was to establish the diet of black-backed jackals on two conservation areas where thicket vegetation dominates (Great Fish River Reserve and Kwandwe Private Game Reserve). The diet was assessed using scats collected monthly from June 2009 to May 2010 and a sample of 25 stomachs over the same period. At both sites and across all seasons, mammalian hair was encountered most often (93% of all scats) and a total of 23 mammal species were consumed. Of the mammals recorded in the scats, hair from several ungulate species was encountered most frequently and these were mostly hider species (offspring hidden in tall vegetation just after birth). On a seasonal basis, the proportion of mammalian hair was lowest in autumn. However, the contribution of fruits (Carissa haematocarpa, Diospyros lycioides and Grewia robusta) to the diet was significantly higher during this season. This suggests that black-backed jackals may employ diet switching in the Eastern Cape as a mechanism to capitalise on seasonally abundant food sources. Based on the stomach content analysis, invertebrates were consumed as frequently as mammalian prey throughout the year but mammalian prey was recorded in greater quantity (i.e. volume and mass). Thus, scat analysis may have overestimated mammalian prey and fruits and underestimated the importance of invertebrates, particularly highly digestible species (e.g. termites). In spite of these differences, scat analysis demonstrated similar general and seasonal trends as the stomach content analysis. Thus, scat analysis can provide an efficient and relatively accurate source of information on the diet of blackbacked jackals in the Eastern Cape. Both stomach content and scat collection methods depicted the black-backed jackal as a generalist and opportunistic predator, mainly relying on mammals and invertebrates. Although the results of my study suggest that black-backed jackal may be important predators of certain ungulate species, further study on their prey preferences, actual biomass ingested and the effects on the population viability of prey species is required in order to develop a robust management plan for the species in the protected areas of the Eastern Cape.

[Partial abstract]: Human-wildlife conflict is a widely observed phenomenon and encompasses a range of negative interactions between humans and wildlife. Depredation upon livestock and game species proves to be the prevalent form of this conflict and often results in the killing of carnivores. Within the South African context, despite intense lethal control, two sympatric mesopredators, the blackbacked jackal (Canis mesomelas) and the caracal (Caracal caracal), remain common enough to be considered a major threat to human livelihoods through depredation. Wildlife ranches and livestock farms dominate the landscape in the Eastern Cape Province. Moreover, human-predator conflict within the region is extensive as both the black-backed jackal and caracal are seen to be inimical by landowners. Understanding this conflict is essential for mitigating any potential adverse environmental reactions (i.e. range collapses or extinctions) and requires knowledge of anthropogenic, ecological and environmental factors. I interviewed 73 land owners across five municipal boundaries in the Eastern Cape to quantify perceptions of predator control methods.

Diet assessments are critical for understanding the foraging behaviour, habitat use and trophic separation of mammalian predators and are vital for gaining insight into how predators influence prey populations. The aim of this research was to qualitatively describe the diet of black-backed jackals (Canis mesomelas, Schreber 1775) using scat analysis on two contrasting land-use types in the Eastern Cape Province, South Africa. Scats were collected on a monthly basis from November 2009 to October 2010 from two game reserves (Great Fish River Reserve and Shamwari Private Game Reserve) and two neighbouring livestock farms. The relative frequency of occurrence of mammal hair (33 – 47 %) and vegetation (32 – 45%)dominated jackal diet throughout the year across the four study sites. Other important prey items included invertebrates (8 – 21 %) and fruit and seeds (3 – 11 %). Birds and reptiles constituted ≤ 2 % of the diet and were only recorded on the game reserves. Significant seasonal dietary shifts were observed on the game reserves but not on the farms. Fruit and seeds were significantly more frequent in the diet during autumn at Great Fish River Reserve and invertebrates were significantly less common in the diet during winter on both reserves. In addition, vegetation was significantly more common in the diet during winter at Shamwari Private Game Reserve. The significant temporal variation of certain prey items is testament to black-backed jackals being opportunistic generalists, foraging on those food items which are most abundant, accessible and energetically beneficial. Land-use type also influenced the diet of black-backed jackals with significantly more invertebrates and, fruit and seeds being recorded on the game reserves than on the farms. By contrast, significantly more mammal hair and vegetation were present in the diet on the farms compared with the game reserves. The mammalian component of the diet was dominated by ruminants and rodents on the game reserves and by ruminants and livestock on the farms. The presence of livestock in the diet of black-backed jackals on the farms highlights their potential impact on the livestock industry in the region and may assist farmers in determining which predators are responsible for stock loss. Previous approaches for identifying mammalian hairs from predator scats have utilised dichotomous keys and reference collections but these are often time-consuming and require a trained individual to carry out the identification. Thus, I also tested the efficacy of an automated pattern recognition programme (HairSnap) for identifying mammalian hairs from black-backed jackal scats. The overall accuracy of the programme was 38 % with black-backed jackal, Greater kudu (Tragelaphus strepsiceros) and striped polecat (Ictonyx striatus) hairs being accurately identified more often (70 – 80 %) than any other species tested. It is likely that both the size and species composition of the sample resulted in the poor accuracy of the programme. However, with the implementation of several improvement measures (e.g. adjustment of the algorithm) the programme may offer a superior, bias-free method of mammalian hair identification. The dietary information gathered here furthers our knowledge of the biology of the blackbacked jackals, especially in the locally important thicket biome. Moreover, understanding their foraging habits allows for more effective management of the species on both game reserves and farmlands. I recommend that future research should focus on quantitatively assessing the diet of black-backed jackals in the Eastern Cape Province and elsewhere. This will compliment the dietary description provided in this study and may offer a biologically more meaningful indication of the relative importance of the prey items.