The black-backed jackal (Lupulella mesomelas),[3][4][5][6] also called the silver-backed jackal, is a medium-sized canine native to eastern and southern Africa. These regions are separated by roughly 900 kilometers.
One region includes the southernmost tip of the continent, including
Compared to members of the genusCanis, the black-backed jackal is a very ancient species, and has changed little since the Pleistocene,[8] being the most basalwolf-like canine, alongside the closely related side-striped jackal.[9] It is a fox-like animal[10] with a reddish brown to tan coat and a black saddle that extends from the shoulders to the base of the tail.[11] It is a monogamous animal, whose young may remain with the family to help raise new generations of pups.[12] The black-backed jackal has a wide array of food sources, feeding on small to medium-sized animals, as well as plant matter and human refuse.[13]
Etymology
The Latinmesomelas is a compound consisting of meso (middle) and melas (black).[11]
The black-backed jackal has occupied eastern and southern Africa for at least 2–3 million years, as shown by fossil deposits in Kenya, Tanzania, and South Africa. Specimens from fossil sites in Transvaal are almost identical to their modern counterparts, but have slightly different nasal bones.[11] As no fossils have been found north of Ethiopia, the species likely has always been sub-Saharan in distribution.[13] The black-backed jackal is relatively unspecialised, and can thrive in a wide variety of habitats, including deserts, as its kidneys are well adapted for water deprivation. It is, however, more adapted to a carnivorous diet than the other jackals, as shown by its well-developed carnassial shear and the longer cutting blade of the premolars.[10]
allozyme divergence within the Canidae indicate that the black-backed jackal and other members of the genus Canis are separated by a considerable degree of genetic distance.[17] Further studies show a large difference in mitochondrial DNA sequences between black-backed jackals and other sympatric "jackal" species, consistent with divergence 2.3–4.5 million years ago.[18]
A mitochondrial DNA (mDNA) sequence alignment for the wolf-like canids gave a phylogenetic tree with the side-striped jackal and the black-backed jackal being the most basal members of this clade, which means that this tree is indicating an African origin for the clade.[9][19]
Because of this deep divergence between the black-backed jackal and the rest of the "wolf-like" canids, one author has proposed to change the species' generic name from Canis to Lupulella.[20]
In 2017, jackal relationships were further explored, with an mDNA study finding that the two black-backed jackal subspecies had diverged from each other 2.5 million years ago to form the south African and east African populations. The study proposes that due to this long separation, which is longer than the separation of the African golden wolf from the wolf lineage, that the two subspecies might warrant separate species status.[21]
In 2019, a workshop hosted by the
IUCN/SSC Canid Specialist Group recommends that because DNA evidence shows the side-striped jackal (Canis adustus) and black-backed jackal (Canis mesomelas) to form a monophyletic lineage that sits outside of the Canis/Cuon/Lycaon clade, that they should be placed in a distinct genus, Lupulella Hilzheimer, 1906 with the names Lupulella adusta and Lupulella mesomelas.[4]
The phylogenetic tree for the wolf-like canids may give conflicting positions for the black-backed jackal and the side-striped jackal relative to the genus Canis members depending on whether the genetic markers were based on mitochondrial DNA or nuclear DNA (from the cell's nucleus). The explanation proposed is that mitochondrial DNA introgression occurred from an ancient ancestor of Canis into the lineage that led to the black-backed jackal around 6.2–5.2 million years ago.[22]
Subspecies
Two subspecies are recognised by
MSW3.[2] These subspecies are geographically separated by a gap which extends northwards from Zambia to Tanzania:[11]
Distinguished from the nominate subspecies by its shorter and wider skull, longer and narrower carnassials, and smaller upper and lower molar grinding areas.
The black-backed jackal is a fox-like canid[10] with a slender body, long legs, and large ears.[11] It is similar to the closely related side-striped jackal and more distantly related to the golden jackal, though its skull and dentition are more robust and the incisors much sharper.[10] It weighs 6–13 kg (13–29 lb),[10] stands 38–48 cm (15–19 in) at the shoulder, and measures 67.3–81.2 cm (26.5–32.0 in) in body length.[11]
The base colour is reddish brown to tan, which is particularly pronounced on the flanks and legs. A black saddle intermixed with silvery hair extends from the shoulders to the base of the tail.
Albino specimens occasionally occur.[10] 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, decreasing to 40 mm at the base of the tail. The hairs of the tail are the longest, measuring 70 mm in length.[13]
Behaviour
Social and territorial behaviours
Scent marking
The black-backed jackal is a
African golden wolf, the species does not howl, instead relying more on yelps. In contrast, black-backed jackals in Southern Africa howl much like golden jackals.[10] When trapped, it cackles like a fox.[12]