Canis mesomelas, Schreber, 1775

Don E. Wilson & Russell A. Mittermeier, 2009, Canidae, Handbook of the Mammals of the World – Volume 1 Carnivores, Barcelona: Lynx Edicions, pp. 352-446 : 419-420

7.

Black-backed Jackal

Canis mesomelas

French: Chacal a dos noir / German: Schabrackenschakal / Spanish: Chacal dorsinegro

Other common names: Silver-backed Jackal

Taxonomy. Canis mesomelas Schreber, 1775 ,

Cape of Good Hope, South Africa.

Different authors have recognized between two and six subspecies. However, considering the regional variation in the species, only two geographically isolated subspecies are recognized here.

Subspecies and Distribution.

C. m. mesomelas Schreber, 1775 — S Africa.

C. m. schmidti Noack, 1897 — E Africa.

Descriptive notes. Head-body 69-90 cm for males and 65-85 cm for females,tail 27- 39-5 cm for males and 26-38-1 cm for females; weight 5-9-12 kg for males and 6-2-9-9 kg for females. Males are slightly larger and heavier than females. Somewhat foxlike in appearance, with a long, pointed muzzle. Diagnostic features include the dark saddle, black bushy tail and reddish flanks and limbs. The ears are large, erect, pointed, and constantly mobile. The overall body color is rufous brown, most intense on the ears, rump, and flanks. A black stripe midway up each flank slopes obliquely from behind the shoulder to the top of the rump; the dark saddle is broadest at the shoulders and tapers to a narrow point at the base of the tail. Anterior to this stripe, just behind the shoulder,is a small vertical stripe, diffuse in some individuals. Above the side markings, the back is marbled black and white giving an overall silver appearance in mature animals. Juveniles and sub-adults have similar markings, but these are drabber and only gain their full intensity at around two years of age. In the drier west and Namib coast in southern Africa the winter coat is a deep reddish brown (especially in males). The bushy tail is dark brown to black with a distinctive black sub-caudal marking. The markings, especially the side and shoulder stripes, are unique and can be used to identifiy individuals. Skull elongated, braincase pear-shaped, rostrum narrow, supra-occipital crest well-developed, bullae rounded, zygomatic arches broad and well-developed, and post-orbital bars incomplete. Dental formula is I 3/3, C 1/1, PM 4/4, M 2/3 = 42. Outer upper incisors larger, more pointed, and more caniniform than others. Upper canines long, curved, and pointed, with a sharp ridge on their posterior faces.

Habitat. Black-backed Jackals are found in a wide variety of habitats including arid coastal desert, montane grassland, arid savannah and scrubland, open savannah, woodland savannah mosaics, and farmland. In general they show a preference for open habitats, tending to avoid dense vegetation. In KwaZulu-Natal, South Africa, they are recorded from sea level to more than 3000 m in the Drakensberg Mountains, and in localities receiving more than 2000 mm of rainfall. Where more than one jackal species occurs in sympatry the selection of habitat is partitioned. Black-backed Jackals preferentially use either open grassland (when sympatric with Side-striped Jackal) or wooded savannah (when sympatric with Golden and Side-striped Jackals). In western Zimbabwe, habitat partitioning was mediated by aggressive encounters in which Blackbacked Jackals displaced Side-striped Jackals from grassland habitats.

Food and Feeding. Generalist feeders. Diet varies according to food availability. When the jackals occur in sympatry with other carnivores using the same prey base, food resources are partitioned. Dietary items typically include small- to medium-sized mammals (e.g. murids, spring hares, young ungulates), reptiles, birds and bird eggs, carrion, and human refuse, as well as invertebrates and plants. In coastal areas, Black-backed Jackals will eat beached marine mammals, seals, fish, and mussels. Invertebrates such as termites and insects are also commonly eaten. Pairs and small groups are often seen foraging together. Groups of between eight and ten aggregate at large carcasses of herbivores, and more than 80 have been recorded at seal colonies on the Namib Desert coast. Such aggregations are accompanied by aggressive behavior between territorial individuals. However, in the south-western Kalahari, where antelope carcasses are uncommon, groups of up to 15 pairs can feed in succession without much overt aggression. Matedjackal pairs will often cooperate in the capture of prey, resulting in a higher success rate. In Botswana, they occasionally form “packs” in order to hunt adult Impala (Aepyceros melampus), and there are also records of their taking adult antelope. On the Namib Desert coast they patrol beaches for beached marine refuse and move along sheltered paths between food-rich patches; the tops of coastal hummocks are used as feeding sites. In this environment, they frequently follow Brown Hyenas (Parahyaena brunnea), from a distance in the hope of securing the odd food item. Their large, mobile ears are used to locate invertebrate and small mammalian prey, which are then captured with a leap followed by an accurate pounce, in a similar manner to Red Foxes.

Activity patterns. Mostly nocturnal, but activity periods may extend well into daylight hours in areas where they are free from persecution.

Movements, Home range and Social organization. The monogamous mated pair, which appears to be a life-long association in most cases, is the basis of social structure, and if one member of a pair dies the other often will lose its territory. Blackbacked Jackals are territorial and use feces and urine to demarcate their territorial boundaries. Territories are spatially and temporally relatively stable, and intruders are aggressively expelled by territory holders. Water sources are shared with intruders, but the intruders perform submissive behaviorto territory holders, even to their pups. Density and group size is dependent on food biomass and dispersion. In South Africa, home range size averaged 18-2 km ® (n = 14). In the more arid south-western Kalahari, adult ranges varied from 2:6-5-2 km? (n = 7) and mean sub-adult ranges were 6-3 km? (n = 4). In Zimbabwe, home ranges were largest in the cold, dry season (c. 1:0-1-3 km?*) and smaller in the hot dry season (c. 0-3-0-6 km?), while in the Rift Valley in Kenya, home ranges varied from 0-7-3-5 km ®*. Home ranges are universally defended and mutually exclusive for pairs, with the exception of a population on the Namibian coast for which average home range size varied from 7-1-24-9 km * (n = 4). A high-pitched, whining howl is used to communicate with group members and is often used to call the group together in the early evening; this may also function in territorial advertisement. Howling often stimulates the same behavior in adjacent territories or in nearby individuals. A three- to five-syllable alarm call, consisting of an explosive yelp followed by a series of shorter high-pitched yelps, is used when disturbed and may be frantic and prolonged when the jackals are mobbing a Leopard (Panthera pardus). A low-pitched, gruff bark is used to warn pups of intruders near the den, and whines are used to call to pups. Also noted is use of a “clattering distress call” and a loud yelp when alarmed. Interestingly, Black-backed Jackals are much less vocal where they occur alongside the Golden Jackal, which is the only jackal species heard to howl in East Africa.

Breeding. Mating is accompanied by increased vocalization and territoriality in both sexes. Dominant individuals within a territory constantly harass same-sex subordinates to prevent them from mating. In southern Africa mating generally occurs from late May to August, and following a gestation period of about 60 days, births occur from around July to October. It has been suggested that summerbirths are timed to coincide with the reproductive season of important rodent prey, and winter births with an increase in the availability of ungulate carcasses at the end of winter. Littersize is typically between one and six, and pups are born in modified termitaria or other convenient burrows, often with multiple entrances. The same den sites may be used from year to year. Pups first emerge from the den at three weeks, are weaned at 8-9 weeks, and are completely independent of the den at 14 weeks. Alloparental care is well documented and consists of feeding pups by regurgitation and guarding them when the parents are foraging. One “helper” may increase the average numberof pups surviving per mated pair from one to three, and two such “helpers” further increase survival to four pups. Pups reach sexual maturity at about eleven months, and even at this early age they can disperse at distances of more than 100 km.

Status and Conservation. CITES not listed. Classified as Least Concern on The [UCN Red List. No legal protection outside protected areas. Regional estimates of abundance are not available. However, Black-backed Jackals are generally widespread, and in Namibia and South Africa they are common in protected areas where suitable habitat occurs. Also occur in many livestock-producing areas, where they are considered vermin; however, despite strenuous control measures in many farming areas of southern Africa, this species is still relatively abundant. Snaring and road accidents may be the commonest cause of jackal mortality in areas of high human density. Black-backed Jackals are persecuted as livestock killers and as carriers of rabies. Population control efforts appear largely ineffective and probably only succeed in producing a temporary reduction in local numbers.

Bibliography. Avery et al. (1987), Bernard & Stuart (1992), Bothma (1971a, 1971b), Bothma et al. (1984), Coetzee (1977), Dreyer & Nel (1990), Ferguson (1980), Ferguson et al. (1983), Fuller et al. (1989), Hiscocks & Perrin (1988), Kaunda (2000), Kaunda & Skinner (2003), Kingdon (1997), Kok (1996), Lamprecht (1978), van Lawick & van Lawick-Goodall (1970), Loveridge (1999), Loveridge & Macdonald (2001, 2002), Loveridge & Nel (2004), McKenzie (1990), Meester et al. (1986), Moehlman (1978, 1979, 1983, 1987), Nel & Loutit (1986), Oosthuizen et al. (1997), Pienaar (1969), Rowe-Rowe (1982, 1983), Stuart (1976).

Figures

2. Red Wolf (Canis rufus), 3. Coyote (Canis latrans), 4. Ethiopian Wolf (Canis simensis), 5. Golden Jackal (Canis aureus), 6. Side-striped Jackal (Canis adustus), 7. Black-backed Jackal (Canis mesomelas)

Subspecies and Distribution. C. m. mesomelas Schreber, 1775 — S Africa. C. m. schmidti Noack, 1897 — E Africa.