habitat_narrative
Terrestrial
Black-backed Jackals are relatively unspecialised and well-suited for an opportunistic lifestyle in a wide variety of habitats (Loveridge & Nel 2013). They have a wide habitat tolerance, occupying habitats including Highveld grassland (Morwe 2013), montane grassland (Rowe-Rowe 1982), scrubland (Skinner & Chimimba 2005), savannah (Wyman 1967; Kingdon 1977; Lamprecht 1978; Moehlman 1983; Fuller et al. 1989; Estes 1991), woodland savannah mosaics (Smithers 1971; Loveridge & Macdonald 2002) and farmland. The Black-backed Jackal has long been perceived as an arid-adapted species (Loveridge & Nel 2013). However, it also occurs in more mesic areas (mean annual precipitation > 1,000 mm; Rowe-Rowe 1982, 1992; Loveridge & Nel 2013) with recent expansions into the more mesic South Coast area (Western Cape), where it was previously absent (see Distribution above). It shows a preference for open habitats, but will occupy dense vegetation (Hoffmann 2014).Until recently, they were considered generalist omnivores (cf. Hayward et al. 2017), consuming whatever resource is readily available (Loveridge & Macdonald 2003; Kok & Nel 2004; Klare et al. 2010; Fourie et al. 2015; Pohl 2015) and scavenging when the opportunity arises. However, they actively hunt small- to medium-sized mammalian prey (Kamler et al. 2010, 2012a; Klare et al. 2010), but also prey on the fawns/lambs of larger ungulates (Klare et al. 2010). Although the diet is dominated by mammals, they supplement their diet with fruit, birds, reptiles, amphibians, insects, and fish (Do Linh San et al. 2009; Brassine & Parker 2012; Kamler et al. 2012a; Morwe 2013; van de Ven et al. 2013; Minnie 2016). The predominance of small- to medium-sized mammals may reflect an optimal foraging strategy, as Black-backed Jackals prefer to prey on mammals with a body mass of 14â26 kg (Hayward et al. 2017). Additionally, they significantly prefer small ungulates (< 30 kg) which hide their young (e.g. Springbok Antidorcas marsupialis and Common Duiker Sylvicapra grimmia; Hayward et al. 2017). Consequently, they have a wide dietary niche that expands and contracts in relation to the local availability and dispersion of resources (Kaunda & Skinner 2003; Klare et al. 2010; Kamler et al. 2012b; Morwe 2013; Pohl 2015; Drouilly et al. in press). Additionally, in the presence of larger carnivores, such as Cheetah (Acinonyx jubatus), Lions, and Leopards, scavenged food sources may contribute substantially to their diet (e.g. Fourie et al. 2015; Minnie 2016), but incongruences in the literature indicate that this might not be the case throughout the assessment region (e.g. Brassine & Parker 2012; Yarnell et al. 2013; Drouilly et al. in press).
In a stable social system, they are monogamous (Moehlman 1987), with the dominant mated pair defending a mutually exclusive breeding territory (Loveridge & Nel 2004). Pair formation may increase hunting success (Lamprecht 1978) and is critical for territorial defence and successful pup rearing (Moehlman 1987). Social structure varies and may consist of family groups (1â8 individuals; Rowe-Rowe 1978, 1984) incorporating the dominant pair and their offspring (Ferguson et al. 1983; Loveridge & Macdonald 2001), as well as subadults that have delayed dispersal to assist in raising their siblings (i.e. helpers; Moehlman 1979; Rowe-Rowe 1982; Ferguson et al. 1983). Additionally, the territorial pair may tolerate subordinate individuals on the fringe of its territory (i.e. floaters; Ferguson et al. 1983). Territorial relaxation/collapse may occur during periods of high resource abundance (e.g. at seal colonies in Namibia; Jenner et al. 2011; Nel et al. 2013), where the dominant pair allows other individuals into its territory (Macdonald 1979; Rowe-Rowe 1982; Ferguson et al. 1983; Hiscocks & Perrin 1988; McKenzie 1990; Oosthuizen et al. 1997; Loveridge & Macdonald 2001, 2003).
Black-backed Jackal mating peaks during winter (Skead 1973) and gestation lasts for 60â70 days (Bernard & Stuart 1992; McKenzie 1993; Walton & Joly 2003). Parturition usually occurs from winter to early spring (Bothma 1971; Bernard & Stuart 1992; McKenzie 1993). Importantly, temporal variation in this reproductive pattern may occur in response to resource availability and abundance (Fairall 1968; Rowe-Rowe 1978; Bernard & Stuart 1992; McKenzie 1993; Bingham & Purchase 2002; Walton & Joly 2003). Females usually have one litter per year, with a litter size of 1â9, depending on the femaleâs body condition (Minnie et al. 2016) and social status (Loveridge & Nel 2013). Additionally, populations experiencing high levels of anthropogenic mortality may produce larger litters relative to populations that are lightly managed or unmanaged (i.e. compensatory reproduction; Minnie et al. 2016).
Pups usually remain in the den from August to November, emerge after 3 weeks, and are weaned at 8â9 weeks of age (Ferguson et al. 1983). They start foraging with their parents at 3 months of age, but remain in close proximity (⤠2 km) to the den until 6 months of age (Ferguson et al. 1983; Moehlman 1987). When they are approximately 7 months old, they start moving further from the den.
They become sexually mature at 11 months, but only start reproducing at 2 years of age (Ferguson et al. 1983; Moehlman 1987). However, populations that are lethally managed may compensate for increased mortality and reproduce at younger ages (i.e. compensatory reproduction; Minnie et al. 2016). Young individuals can stay in the natal territory and assist with rearing the next litter (i.e. helpers), or disperse in search of mates and a territory (Ferguson et al. 1983; Moehlman 1987). According to Rowe-Rowe (1992), adults seldom live beyond 7 years.
Home range size varies considerably, with ranges between 4 and 33 km2 being reported. Humphries et al (2016) estimated mean resident home ranges (95% FK) across seasons for adult males, adult females and juvenile males; these were 11.4 ± 4.3 km2, 5.6 ± 0.36 km2 and 2.15 ± 0.45 km2, respectively. While in the Kalahari Gemsbok National Park (Northern Cape) home ranges averaged between 2.56 and 8.8 km2 (Ferguson et al 1983). Variations in home range size may be attributed to variation in food availability, as individuals occupying areas with higher prey density tend to have smaller home ranges (e.g. Ferguson et al. 1983). Further, seasonal variation is apparent and home range size decreases during the whelping season (Loveridge & Macdonald 2001).
Home range size also varies between social classes, with territorial adults having smaller home ranges than subadults (e.g. Ferguson et al. 1983). This may be due to subordinate individuals dispersing in search of mates and territories, whereas dominant pairs are resident (Ferguson et al. 1983; Humphries et al. 2016). In general, the home ranges of dominant pairs do not overlap (< 10 %) with other mated pairs (Ferguson et al. 1983). However, the home ranges of subordinate individuals may overlap extensively with both subordinate and dominant individuals (Ferguson et al. 1983; Rowe-Rowe 1982).
Ecosystem and cultural services: Black-backed Jackals play a vital role in predatorâprey interactions and ecosystem functioning. This role may be even more pronounced in areas where large carnivores have been extirpated (e.g. farmlands) leaving Black-backed Jackals (and Caracals) to fulfil the role of apex predators. Consequently, they may regulate populations of smaller carnivores and prey (du Plessis 2013; Bagniewska & Kamler 2014). Given their preference for small- to medium-sized ungulates, they may regulate the populations of species falling within this preferred prey weight range (e.g. Springbok: Klare et al. 2010; Morwe 2013; Blesbok Damaliscus pygargus phillipsi: du Plessis 1972).
Black-backed Jackals consume small rodents, thus it is conceivable that they may regulate these populations. For example, Bagniewska and Kamler (2014) showed that they may suppress prey populations such as Cape Ground Squirrels (Xerus inauris) and hares (Lepus spp.). However, little evidence in support of this prey regulation hypothesis exists (Swanepoel et al. 2017). Thus, the role of this species in regulating crop pests and the spread of diseases by these pests (many of these rodent species act as disease vectors), as well as other herbivores which may compete with livestock for grazing (e.g. Hyrax Procavia capensis: Pohl 2015) is unclear.
Black-backed Jackals may also suppress smaller carnivore populations via lethal (intraguild predation; e.g. Yellow Mongoose Cynictis penicillata, African Striped Weasel Poecilogale albinucha, Small-spotted Genet Genetta genetta, and Bat-eared Fox: Klare et al. 2010; Kamler et al. 2012a; Bagniewska & Kamler 2014; Drouilly et al. in press) and non-lethal (competition; e.g. Cape Fox Vulpes chama: Kamler et al. 2013) interactions.
Further, anecdotal evidence suggests that the competitive interactions between Black-backed Jackals and Caracals on livestock farms may produce concurrent fluctuations in population densities (du Plessis 2013). When Black-backed Jackal densities are reduced due to human persecution, Caracal densities apparently increase (Pringle & Pringle 1979; Ferreira 1988). In the northeastern part of the assessment area (northern Limpopo, Mpumalanga, and KwaZulu-Natal provinces), they occur in sympatry with Side-striped Jackals (Canis adustus). Here, Black-backed Jackals may aggressively exclude Side-striped Jackals from preferred habitats, as observed in Zimbabwe (Loveridge 1999).
The Black-backed Jackal is a common character in Bushmen, Hottentot, and Bantu folklore and is often portrayed as a trickster (Stewart 2004). Jackals in general are seen as sly and greedy and depict both the weaknesses and strengths of human nature (Stewart 2004). Character traits such as vanity, greed, naïvety, selfishness, and cruelty are often synonymous with jackals (Stewart 2004). In most cases, the trickster is a small creature that poses no threat to larger animals and often outwits enemies that have a competitive advantage (Stewart 2004). Additionally, the Black-backed Jackal is also seen as an important ancestral spirit manifestation for both isiXhosa and isiZulu people (P. Bernard pers. comm. 2015). Traditional healers have spirit animal guides and these are shown in a dream to the healer. It is then incumbent on the healer to incorporate the skin of the animal guides into their traditional garb. Black-backed Jackal skins are often incorporated into the head-gear (known as isidlokolo) of a traditional healer if the animal is that healerâs animal guide (P. Bernard pers. comm. 2015).
