African wolf

Aristotle wrote of wolves living in Egypt, mentioning that they were smaller than the Greek kind. Georg Ebers wrote of the wolf being among the sacred animals of Egypt, describing it as a "smaller variety" of wolf to those of Europe, and noting how the name Lykopolis, the Ancient Egyptian city dedicated to Anubis, means "city of the wolf".[21][22]

The African wolf was first recognised as being a separate species from the golden jackal by Frédéric Cuvier in 1820, who described it as being a more elegant animal, with a more melodic voice and a less strong odour. The binomial name he chose for it was derived from the Arcadian Anthus family described by Pliny the Elder in his Natural History, whose members would draw lots to become werewolves.[2] Eduard Rüppell proposed that the animal was the ancestor of Egyptian sighthounds, and named it Wolfs-hund (wolf dog),[23] while C.H. Smith named it "thoa" or "thous dog".[24]

Illustration of golden jackal-African wolf hybrids bred in captivity (1821).

An attempt was also made in 1821 to hybridise the two species in captivity, resulting in the birth of five pups, three of which died before weaning. The two survivors were noted to never play with each other, and had completely contrasting temperaments: One pup inherited the golden jackal's shyness, while the other was affectionate toward its human captors.[7] English biologist G.J. Mivart emphasized the differences between the African wolf and the golden jackal in his writings:

... it is a nice question whether the Common Jackal of North Africa should or should not be regarded as of the same species [as the golden jackal] ... Certainly the differences of coloration which exist between these forms are not nearly so great as those which are to be found to occur between the different local varieties of C. lupus. We are nevertheless inclined ... to keep the North-African and Indian Jackals distinct ... The reason why we prefer to keep them provisionally distinct is that though the difference between the two forms (African and Indian) is slight as regards coloration, yet it appears to be a very constant one. Out of seventeen skins of the Indian form, we have only found one which is wanting in the main characteristic as to difference of hue. The ears also are relatively shorter than in the North-African form. But there is another character to which we attach greater weight. However much the different races of Wolves differ in size, we have not succeeded in finding any constant distinctive characters in the form of the skull or the proportions of the lobes of any of the teeth. So far as we have been able to observe, such differences do exist between the Indian and North-African Jackals.

— Mivart (1890)[25]

Comparative illustration of C. aureus (top) and C. lupaster (bottom).

The canids present in Egypt in particular were noted to be so much more gray wolf-like than populations elsewhere in Africa that W.F. Hemprich and C.G. Ehrenberg gave them the binomial name Canis lupaster in 1832. Likewise, T.H. Huxley, upon noting the similarities between the skulls of lupaster and Indian wolves, classed the animal as a subspecies of the gray wolf. However, the animal was subsequently synonymised with the golden jackal by Ernst Schwarz in 1926.

In 1965, the Finnish paleontologist Björn Kurtén wrote:

The taxonomy of the Jackals in the Near East is still a matter of dispute. On the basis of skeletal material, however, it can be stated that the Wolf Jackal is specifically distinct from the much smaller Golden Jackal.[26]

In 1981, zoologist Walter Ferguson argued in favor of lupaster being a subspecies of the gray wolf based on cranial measurements, stating that the classing of the animal as a jackal was based solely on the animal's small size, and predated the discovery of C. l. arabs, which is intermediate in size between C. l. lupus and lupaster.[22]

Further doubts over its being conspecific with the golden jackal of Eurasia arose in December 2002, when a canid was sighted in Eritrea's Danakil Desert whose appearance did not correspond to that of the golden jackal or the six other recognized species of the area, but strongly resembled that of the gray wolf. The area had previously been largely unexplored because of its harsh climate and embroilment in the Eritrean War of Independence and subsequent Eritrean–Ethiopian War, though local Afar tribesmen knew of the animal, and referred to it as wucharia (wolf).[13]

The animal's wolf-like qualities were confirmed in 2011, when several golden "jackal" populations in Egypt and the Horn of Africa classed as Canis aureus lupaster[19] were found to have mtDNA sequences more closely resembling those found in gray wolves than those of golden jackals.[21] These wolf-like mtDNA sequences were found to occur over a 6,000 km wide area, encompassing Algeria, Mali and Senegal. Furthermore, the sampled African specimens displayed much more nucleotide and haplotype diversity than that present in Indian and Himalayan wolves, thus indicating a larger ancestral population, and an effective extant population of around 80,000 females. Both these studies proposed reclassifying Canis aureus lupaster as a subspecies of the gray wolf.[27]

In 2015, a more thorough comparative study of mitochondrial and nuclear genomes on a larger sample of wolf-like African canids from northern, eastern and western Africa showed that they were in fact all distinct from the golden jackal, with a genetic divergence of around 6.7%,[5][28][29] which is greater than that between gray wolves and coyotes (4%) and that between gray wolves and domestic dogs (0.2%).[30] Furthermore, the study showed that these African wolf-like canids (renamed Canis lupaster, or African wolves) were more closely related to gray wolves and coyotes than to golden jackals,[5][31] and that C. l. lupaster merely represents a distinct phenotype of the African wolf rather than an actual gray wolf. The phylogenetic tree below is based on nuclear sequences:[5]

It was estimated that the African wolf diverged from the wolf–coyote clade 1.0–1.7 million years ago, during the Pleistocene, and therefore its superficial similarity to the golden jackal (particularly in East Africa, where African wolves are similar in size to golden jackals) would be a case of parallel evolution. Considering its phylogenetic position and the canid fossil record, it is likely that the African wolf evolved from larger ancestors that became progressively more jackal-like in size upon populating Africa on account of interspecific competition with both larger and smaller indigenous carnivores. Traces of African wolf DNA were identified in golden jackals in Israel, which adjoins Egypt, thus indicating the presence of a hybrid zone.[5] The study's findings were corroborated that same year by Spanish, Mexican and Moroccan scientists analyzing the mtDNA of wolves in Morocco, who found that the specimens analyzed were distinct from both golden jackals and gray wolves but bore a closer relationship to the latter.[6] Studies on RAD sequences found instances of African wolves hybridizing with both feral dogs and Ethiopian wolves.[32]

In 2017, it was proposed by scientists at the Oslo and Helsinki Universities that the binomial name C. anthus was a nomen dubium, on account of the fact that Cuvier's 1820 description of the holotype, a female collected from Senegal, seems to be describing the side-striped jackal rather than the actual African wolf, and does not match the appearance of a male specimen described by Cuvier in his later writings. This ambiguity, coupled with the disappearance of the holotype's remains, led to the scientists proposing giving priority to Hemprich and Ehrenberg's name C. lupaster, due to the type specimen having a more detailed and consistent description, and its remains being still examinable at the Museum für Naturkunde.[19] The following year, a major genetic study of Canis species also referred to the African wolf as Canis lupaster.[8]

In 2019, a workshop hosted by the IUCN/SSC Canid Specialist Group recommended that because the specimen identified as Canis anthus Cuvier, 1820 was uncertain, the species should be known as Canis lupaster Hemprich and Ehrenberg, 1832 until Canis anthus can be validated.[33]

In 2018, whole genome sequencing was used to compare members of the genus Canis. The study supports the African wolf being distinct from the golden jackal, and with the Ethiopian wolf being genetically basal to both. Two genetically distinct African wolf populations exist in northwestern and eastern Africa. This suggests that Ethiopian wolves – or a close and extinct relative – once had a much larger range within Africa to admix with other canids. There is evidence of gene flow between the eastern population and the Ethiopian wolf, which has led to the eastern population being distinct from the northwestern population. The common ancestor of both African wolf populations was a genetically admixed canid of 72% gray wolf and 28% Ethiopian wolf ancestry. There is evidence of gene flow between African wolves, golden jackals, and gray wolves. One African wolf from the Egyptian Sinai Peninsula showed high admixture with the Middle Eastern gray wolves and dogs, highlighting the role of the land bridge between the African and other continents in canid evolution. African wolves form a sister clade to Middle Eastern gray wolves based on mitochondrial DNA, but to coyotes and gray wolves based on nuclear DNA.[8]

Between 2011 and 2015, two mtDNA studies found that the Himalayan wolf and Indian wolf were closer to the African wolf than they were to the Holarctic gray wolf.[21][5] In 2017, a study of mitochondrial DNA, X-chromosome (maternal lineage) markers and Y-chromosome (male lineage) markers found that the Himalayan wolf is genetically basal to the Holarctic gray wolf. The Himalayan wolf shares a maternal lineage with the African wolf, and possesses a unique paternal lineage that falls between the gray wolf and the African wolf.[34]

Although in the past several attempts have been made to synonymise many of the proposed names, the taxonomic position of West African wolves, in particular, is too confused to come to any precise conclusion, as the collected study materials are few. Prior to 1840, six of the 10 supposed West African subspecies were named or classed almost entirely because of their fur color.[35]

The species' display of high individual variation, coupled with the scarcity of samples and the lack of physical barriers on the continent preventing gene flow, brings into question the validity of some of the West African forms.[35] However, a study showed that the genetic divergence of all of the African wolves occurred between 50,000 and 10,500 years ago, with most occurring between 30,000 and 16,000 years ago during the Late Glacial Maximum (33,000–16,000 years ago). There were very dry conditions across the Sahara during this period. The study proposes that these wolves were isolated in refugia and therefore isolated for hundreds of generations, leading to genetic divergence.[36]

The African wolf's social organisation is extremely flexible, varying according to the availability and distribution of food. The basic social unit is a breeding pair, followed by its current offspring, or offspring from previous litters staying as "helpers".[15] Large groups are rare, and have only been recorded to occur in areas with abundant human waste. Family relationships among African wolves are comparatively peaceful in relation to those of the black-backed jackal; although the sexual and territorial behavior of grown pups is suppressed by the breeding pair, they are not actively driven off once they attain adulthood. African wolves also lie together and groom each other much more frequently than black-backed jackals. In the Serengeti, pairs defend permanent territories encompassing 2–4 km², and will vacate their territories only to drink or when lured by a large carcass.[4] The pair patrols and marks its territory in tandem. Both partners and helpers will react aggressively towards intruders, though the greatest aggression is reserved for intruders of the same sex; pair members do not assist each other in repelling intruders of the opposite sex.[4]

Threat postures in C. l. lupaster (left) and C. l. anthus (right)

The African wolf's courtship rituals are remarkably long, during which the breeding pair remains almost constantly together. Prior to mating, the pair patrols and scent marks its territory. Copulation is preceded by the female holding her tail out and angled in such a way that her genitalia are exposed. The two approach each other, whimpering, lifting their tails and bristling their fur, displaying varying intensities of offensive and defensive behavior. The female sniffs and licks the male's genitals, whilst the male nuzzles the female's fur. They may circle each other and fight briefly. The copulatory tie lasts roughly four minutes. Towards the end of estrus, the pair drifts apart, with the female often approaching the male in a comparatively more submissive manner. In anticipation of the role he will take in raising pups, the male regurgitates or surrenders any food he has to the female. In the Serengeti, pups are born in December–January, and begin eating solid food after a month. Weaning starts at the age of two months, and ends at four months. At this stage, the pups are semi-independent, venturing up to 50 meters from the den, even sleeping in the open. Their playing behavior becomes increasingly more aggressive, with the pups competing for rank, which is established after six months. The female feeds the pups more frequently than the male or helpers do, though the presence of the latter allows the breeding pair to leave the den and hunt without leaving the litter unprotected.[4]

The African wolf's life centers around a home burrow, which usually consists of an abandoned and modified aardvark or warthog earth. The interior structure of this burrow is poorly understood, though it is thought to consist of a single central chamber with 2–3 escape routes. The home burrow can be located in both secluded areas or surprisingly near the dens of other predators.[39]

African wolves frequently groom one another, particularly during courtship, during which it can last up to 30 minutes. Nibbling of the face and neck is observed during greeting ceremonies. When fighting, the African wolf slams its opponents with its hips, and bites and shakes the shoulder. The species' postures are typically canine, and it has more facial mobility than the black-backed and side-striped jackals, being able to expose its canine teeth like a dog.[4]

The vocalisations of the African wolf are similar to those of the domestic dog, with seven sounds having been recorded,[17] including howls, barks, growls, whines and cackles.[4] Subspecies can be recognised by differences in their howls.[17] One of the most commonly heard sounds is a high, keening wail, of which there are three varieties; a long single toned continuous howl, a wail that rises and falls, and a series of short, staccato howls. These howls are used to repel intruders and attract family members. Howling in chorus is thought to reinforce family bonds and establish territorial status.[4] A comparative analysis of African wolf and some gray wolf subspecies' howls demonstrated that the former's howls bear similarities to those of the Indian wolf, being high-pitched and of relatively short duration.[40]

A Serengeti wolf (C. l. bea) navigating through a herd of blue wildebeest in the Ngorongoro National Park, Tanzania

The African wolf rarely catches hares, due to their speed. Gazelle mothers (often working in groups of two or three) are formidable when defending their young against single wolves, which are much more successful in hunting gazelle fawns when working in pairs. A pair of wolves will methodically search for concealed gazelle fawns within herds, tall grass, bushes and other likely hiding places.[4]

Although it is known to kill animals up to three times its own weight, the African wolf targets mammalian prey much less frequently than the black-backed jackal overall.[4] On capturing large prey, the African wolf makes no attempt to kill it; instead it rips open the belly and eats the entrails. Small prey is typically killed by shaking, though snakes may be eaten alive from the tail end. The African wolf often carries away more food than it can consume, and caches the surplus, which is generally recovered within 24 hours.[39] When foraging for insects, the African wolf turns over dung piles to find dung beetles. During the dry seasons, it excavates dung balls to reach the larvae inside. Grasshoppers and flying termites are caught either in mid-air or by pouncing on them while they are on the ground. It is fiercely intolerant of other scavengers, having been known to dominate vultures on kills – one can hold dozens of vultures at bay by threatening, snapping and lunging at them.[4]

C. lupaster has a wide range across the upper half of Africa, occurring in Senegal, Burkina Faso, Cameroon, the Central African Republic, Djibouti, Eritrea, Ethiopia, Guinea, Mali, Mauritania, Niger, Somalia, South Sudan, Sudan, Western Sahara, Nigeria, Chad, Morocco, Algeria, Tunisia, Libya, Kenya, Egypt, and Tanzania. Fossil finds dating back to the Pleistocene indicate that the species' range was not always restricted to Africa, with remains having been found in the Levant and Saudi Arabia.[19] In Tanzania, the African wolf is limited to a small area of the north between the western slopes of Mount Kilimanjaro and the centre of the Serengeti. In the latter area, it occurs mostly in the short-grass plains, the floor of the Ngorongoro Crater, and the plains between the Olmoti and Empakai Craters, being relatively rare in Serengeti National Park, Loliondo and the Maswa game reserve. The species also inhabits the Lake Natron area and West Kilimanjaro. It is sometimes found in the northern part of Arusha National Park, and as far south as Manyara. In areas where it is common, such as the short-grass plains of Serengeti National Park and the Ngorongoro Crater, population densities can range between 0.5 and 1.5 specimens per km². A population decrease of 60% has been recorded in the southern plains of Serengeti National Park since the early 1970s, though the reasons are unknown.[41]

The African wolf inhabits a number of different habitats; in Algeria it lives in Mediterranean, coastal and hilly areas (including hedged farmlands, scrublands, pinewoods and oak forests), while populations in Senegal inhabit tropical, semi-arid climate zones including Sahelian savannahs. Wolf populations in Mali have been documented in arid Sahelian massifs.[27] In Egypt, the African wolf inhabits agricultural areas, wastelands, desert margins, rocky areas, and cliffs. At Lake Nasser, it lives close to the lakeshore.[16] In 2012, African wolves were photographed in Morocco's Azilal Province at an elevation of 1,800 meters.[14][3] It apparently does well in areas where human density is high and natural prey populations low, as is the case in the Enderta district in northern Ethiopia.[42] This wolf has been reported in the very dry Danakil Depression desert on the coast of Eritrea, in eastern Africa.[13]

Serengeti wolf (C. l. bea) eating an agama

In West Africa, the African wolf mostly confines itself to small prey, such as hares, rats, ground squirrels and cane rats. Other prey items include lizards, snakes, and ground-nesting birds, such as francolins and bustards. It also consumes a large amount of insects, including dung beetles, larvae, termites and grasshoppers. It will also kill young gazelles, duikers and warthogs.[39] In East Africa, it consumes invertebrates and fruit, though 60% of its diet consists of rodents, lizards, snakes, birds, hares and Thomson's gazelles.[15] During the wildebeest calving season, African wolves will feed almost exclusively on their afterbirth.[17] In the Serengeti and Ngorongoro Crater, less than 20% of its diet comes from scavenging.[4] In Senegal, where both C. l. anthus and C. l. lupaster coexist, some degree of niche segregation is apparent in their choice of prey; the former is reputed to feed primarily on lambs, whereas the latter attacks larger prey, such as sheep, goats and cattle.[27]

The African wolf generally manages to avoid competing with black-backed and side-striped jackals by occupying a different habitat (grassland, as opposed to the closed and open woodlands favored by the latter two species) and being more active during the daytime.[43] Nevertheless, the African wolf has been known to kill the pups of black-backed jackals,[15] but has in turn been observed to be dominated by adults during disputes over carcasses.[17] It often eats alongside African wild dogs, and will stand its ground if the dogs try to harass it.[4] Encounters with Ethiopian wolves are usually antagonistic, with Ethiopian wolves dominating African wolves if the latter enter their territories, and vice versa. Although African wolves are inefficient rodent hunters and thus not in direct competition with Ethiopian wolves, it is likely that heavy human persecution prevents the former from attaining numbers large enough to completely displace the latter.[44] Nevertheless, there is at least one record of an African wolf pack adopting a male Ethiopian wolf.[45]

African wolves will feed alongside spotted hyenas, though they will be chased if they approach too closely. Spotted hyenas will sometimes follow wolves during the gazelle fawning season, as wolves are effective at tracking and catching young animals. Hyenas do not take to eating wolf flesh readily; four hyenas were reported to take half an hour in eating one. Overall, the two animals typically ignore each other when no food or young is at stake.[46] Wolves will confront a hyena approaching too closely to their dens by taking turns in biting the hyena's hocks until it retreats.[4]

African wolves in the Serengeti are known to carry the canine parvovirus, canine herpesvirus, canine coronavirus and canine adenovirus.[15]