By the mid-nineteenth century, indigenous mammals had been drastically reduced in South Africa due to prolific hunting and extermination of species that were perceived as competition for livestock (Beinart 2003). With the drastic decrease of indigenous prey items, predators turned to livestock prey items to meet their feeding requirements and have thus been a problem for South African livestock farmers for generations (Bienart 2003). Although farmers make use of various methods to protect their livestock from predators, the perceived losses to predation are still considered to be very high (Strauss 2009, van Niekerk 2010) suggesting that current methods are either not effective enough or there are other factors not yet fully understood thus preventing the situation from being managed effectively.
Both jackal and caracal have complex breeding systems but the impacts of intensive culling on their reproduction is not well understood. Some studies suggest that intensive culling not only influences genetic heterozygosity (Jackal: James 2014), but increases pressure on these predators, resulting in breeding from earlier ages (Ferguson et al 1983; Minnie et al 2016), and a reduction in territory sizes, (Ferguson et al 1983). Compensatory breeding and in-migration, underlines the difficulty of eradicating jackals from the landscape, especially in the presence of easy food sources as domestic livestock.
These suggestions could be a partial explanation as to why in spite of intensive jackal eradication programmes across southern Africa for many years, the species is still relatively abundant in these areas (Blaum et al. 2009). The removal of dominant jackal in farming areas results in population gaps, which are then rapidly filled by neighbouring territorial pairs or dispersing sub-adults from neighbouring territories (Bothma 2010). This then increases the number of jackal in the immediate area, which may then result in an over-exploitation of the natural prey, which could then force predators to search for alternative prey sources such as livestock. It is also possible that incoming sub-adult jackals are inexperienced and less efficient hunters than the adult jackals that were removed and thus are more likely to catch prey (livestock) that are easier and less risky to catch.
For the development of effective management and conservation strategies for a species, it is crucial to have an understanding of the species’ population structure and history. However, it is not only the understanding of the pattern of genetic diversity but also the process generating the observed diversity that is important (Moritz 1999, 2002). Investigations on population structures have been conducted using mitochondrial DNA (MtDNA) (Avise et al 1987). In mammals the control region of the mtDNA genome is the most variable section as it is characterised by quick changes in sequence and length (Saccone et al. 1991), thus making mtDNA suitable for population genetic analysis. In mammals the mtDNA genome is inherited from an individual’s mother, thus yielding a female-biased assessment of population structure (Zhang & Hewitt 1996). A complete picture of population structure can however, be obtained by combining mtDNA data with microsatellites (Simonsen et al. 1998). Microsatellite analysis is suitable for fine scale population structure analysis (Simonsen et al. 1998). Using both nuclear and mtDNA it will be possible to look at the diversity of the jackal and caracal population within the study area and compare the findings to populations in other farming areas of South Africa.
Public support for predator control has decreased over time (Treves & Naughton-Treves 2005) and is likely to continue to decrease in the future. It is therefore imperative that attempts to find solutions to the problem of predator–farmer conflict that will accommodate both the conservation of predators in, and around livestock farms and the livelihoods of livestock farmers are made.
Ear tissue samples of various sex and ages (191 jackal and 33 caracal) were collected from carcasses after routine culling operations of these species on farms within the Northern Karoo of South Africa. Through the use of genetic analysis, the tissue samples from these carcasses will be used to determine the genetic structure and relatedness between culled black backed jackal and between culled caracal.