• Description
  • More

 

The Black-backed Jackal (Canis mesomelas), also known as the Silver-backed or Red Jackal, is a species of jackal which inhabits two areas of the African continent separated by roughly 900 km. One region includes the southern-most tip of the continent including South Africa, Namibia, Botswana, and Zimbabwe.

The other area is along the eastern coastline, including Kenya, Somalia, and Ethiopia. It is listed by the IUCN as least concern, due to its widespread range and adaptability, although it is still persecuted as a livestock predator and rabies vector.  The fossil record indicates that the species is the oldest extant member of the genus Canis.  Although the most lightly built of jackals, it is the most aggressive, having been observed to singly kill animals many times its own size, and its intra-pack relationships are more quarrelsome.

Evolution

The black-backed jackal is an exceptionally stable and ancient form of canid, with many fossils dating as far back as the Pleistocene epoch. Fossil jackals discovered in the Transvaal cave are roughly the same size as their descendents, though their nasal bones differ in size. Although numerous fossils dating back to 2 million years ago have been found in Kenya, Tanzania, and South Africa, they are entirely absent in Ethiopia, indicating that the species has never expanded past sub-saharan Africa. Mitochondrial DNA analysis' display a large sequence divergence in black-backed jackals from other jackal species, indicating they diverged 2.3–4.5 million years ago.

Physical description


Black-backed jackals are small, foxlike canids which measure 38-48 cm in shoulder height and 68-74.5 cm in length. The tail measures 30-38 cm in length. Weight varies according to location; East African jackals weigh 7-13.8 kg (15-30 lb). Male jackals in Zimbabwe weigh 6.8-9.5 kg (15-21 lb), while females weigh 5.4-10 kg (12-22 lb). Their skulls are elongated with pear-shaped braincases and narrow rostrums. The black-backed jackal's skull is similar to that of the Side-striped Jackal, but is less flat, and has a shorter, broader rostrum. Its sagittal crest and zygomatic arches are also heavier in build. Its carnassials are also larger than those of its more omnivorous cousin. Black-backed jackals are taller and longer than golden jackals, but have smaller heads.The general colour is reddish brown to tan, while the flanks and legs are redder. Males tend to be more brightly coloured than females, particularly in their winter coat. The back is intermixed with silver and black hairs, while the underparts are white. Their tails have a black tip, unlike side-striped jackals which have white tipped tails. The back of the ears are light yellowish brown, well clothed with hair without and within. The hair of the face measures 10-15 mm in length, and lengthens to 30-40 mm on the rump. The guard hairs of the back are 60 mm on the shoulder and decreasing to 40 mm at the base of the tail. The hairs of the tail are the longest, measuring 70 mm in length.

Behaviour


Jackals usually den in holes made by other species, though they will occasionally dig their own; females will dig tunnels 1-2 metres in depth with a 1 metre wide entrance. Black-backed jackals are monogamous and territorial animals, whose social organisation greatly resembles that of golden jackals. However, unlike the latter species, the assistance of elder offspring in helping raise the pups of their parents has a greater bearing on pup survival rates. During the mating season, they become increasingly more vocal and territorial, with dominant animals preventing same sexed subordinates from mating through constant harassment. In southern Africa, mating occurs from late May to August, with a 60 day gestation period. Pups are born from July to October. It is theorised that summer births are timed to coincide with population peaks of vlei rats and four striped grass mice, while winter births are timed for ungulate calving seasons. Litters usually consist of 3-6 pups. For the first 3 weeks of their lives, the pups are kept under constant surveilance by their mother, while the father and elder offspring provide food. They typically leave the den after 3 weeks, and become independant at 6-8 months. Pups have drab coloured coats, which only reach full intensity at the age of two years. Unlike golden jackals, which have comparatively amicable intra-pack relationships, black-backed jackal pups become increasingly quarrelsome as they age, and establish more rigid dominance heirarchies. Dominant cubs will appropriate food, and become independant at an earlier age.

Diet


Black-backed jackals are omnivores, which feed on invertebrates such as beetles, grasshoppers, crickets, termites, millipedes, spiders and scorpions. They will also feed on mammals such as rodents, hares and young antelopes up to the size of topi calves. They will also feed on carrion, lizards, snakes. They will occasionally feed on fruits and berries.

In coastal areas, they will feed on beached marine mammals, seals, fish and mussels. A single jackal is capable of killing a healthy adult impala. Adult dik dik and Thompson's gazelles seem to be the upper limit of their killing capacity, though they will target larger species if they are sick, with one pair having been observed to harass a crippled bull rhinocerous. They typically kill tall prey by biting at the legs and loins, and will frequently go for the throat. In Serengeti woodlands, they feed heavily on African Grass Rats. In East Africa, during the dry season, they hunt the young of gazelles, impalas, topi, tsessebe and warthogs. In South Africa, black-backed jackals frequently prey on antelopes (primarily impala and springbok and occasionally duiker, reedbuck and steenbok), carrion, hares, hoofed livestock, insects, and rodents. They will also prey on small carnivores such as mongooses, polecats and wild cats. On the coastline of the Namib Desert, jackals feed primarily feed on marine birds (mainly Cape and white breasted cormorants and jackass penguins), mammals (including cape fur seals), fish, and insects.

In the Ngorongoro Crater, where both black-backed and golden jackals are sympatric in equal numbers, the former species congregates at carcasses in large numbers far more readily, and is bolder in approaching larger predators.

Interspecific predatory relationships

Eagles are the primary threat to cubs; bateleur eagles will carry off pups up to the age of 10 weeks, while the larger martial eagles will even target subadults. Spotted hyenas and golden jackals will also kill unprotected pups. The main threat to adults are leopards.

Although smaller than side-striped jackals, the more aggressive black-backed jackals have been observed to dominate them in direct encounters. Sounds made by black-backed jackals include yelling, yelping, woofing, whining, growling and cackling. When calling to one another, they emit an abrupt yelp followed by a succession of shorter yelps. Jackals of the same family will answer each others calls, while ignoring those of strangers. When threatened by predators, they yell loudly. Black-backed jackals in southern Africa are known to howl much like golden jackals. They woof when startled, and cackle like foxes when trapped.In their northeastern range, black-backed jackals inhabit habitat zones intermediate to the grasslands favoured by golden jackals and the woodlands favoured by side-striped jackals. In the Serengeti, black backed jackals predominate in Acacia and Commiphora woodlands, while the golden species limits itself to open plains. In their southern range, where golden jackals are absent, black backed jackals are found in more open and arid habitats, though preferring areas with scattered brush.