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African Golden Wolf - Canis anthus
#1
African Golden Wolf - Canis anthus

[Image: 2461l-chacal-dore-canis-aureus-anthus_zpsvvu8wiea.jpg]

Temporal range: 1-1.7–0 Ma Early Pleistocene – Recent

Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Mammalia
Order:Carnivora
Family:Canidae
Genus:Canis
Species:Canis athus

The African golden wolf (Canis anthus), also known as the African wolf or thoa, is a canid native to north and northeastern Africa. The species is common in North and north-east Africa, occurring from Senegal to Egypt in the east, in a range including Morocco, Algeria, and Libya in the north to Nigeria, Chad and Tanzania in the south. It is a desert-adapted canid, and is common in plains and steppe areas, including ones lacking abundant water. It is primarily a predator, targeting invertebrates and mammals as large as gazelle fawns, though larger animals are sometimes taken. Other foodstuffs include animal carcasses, human refuse, and fruit. The African wolf is a monogamous and territorial animal, whose social structure includes yearling offspring remaining with the family to assist in raising their parents' younger pups.

It was previously classified as an African variant of the Eurasian Golden Jackal, with at least one subspecies (Canis anthus lupaster) having been classified as a Grey Wolf. In 2015, a series of analyses on the species' mtDNA and nuclear genome demonstrated that it was in fact distinct from the golden jackal, and more closely related to Grey Wolves and Coyotes. It is nonetheless still close enough to the golden jackal to produce hybrid offspring, as indicated through genetic tests and a 19th century captive crossbreeding experiment. As the IUCN's golden jackal page has not been updated since 2008, it has yet to recognise the distinctiveness of the African wolf and give it its own conservation status, with population estimates being completely lacking.

Physical description
The African wolf is a small canid, with both sexes weighing between 7-15 kg (15.6-33 lbs), and standing 40 cm in height. It has a relatively long snout and ears, while the tail is comparatively short, measuring 20 cm in length. Fur colour varies individually, seasonally and geographically, though the typical colouration is yellowish to silvery grey, with slightly reddish limbs and black speckling on the tail and shoulders. The throat, abdomen and facial markings are usually white, and the eyes are amber coloured. Females bear 4-8 teats. Although superficially similar to the Eurasian Golden Jackal (particularly in East Africa), the African golden wolf has a more pointed muzzle and sharper, more robust teeth. The ears are longer in the golden wolf, and the skull has a more elevated forehead.

Taxonomic history
The African golden wolf was first recognised as being a separate species from the Eurasian 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. Eduard Rüppell proposed that the animal was the ancestor of Egyptian sighthounds, and named it Wolf's-hund (wolf dog), while Charles Hamilton Smith named it "thoa" or "thous dog". 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 inherited the golden jackal's shyness, while the other was affectionate toward its human captors. English biologist St. George Jackson Mivart emphasised 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 is 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 reasons 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)

Although subsequently synonymised with the golden jackal, new doubts over its being conspecific with the golden jackal arose in 2011, when several golden "jackal" populations in Egypt and the Horn of Africa classed as Canis aureus lupaster were found to have mtDNA sequences more closely resembling those in Grey Wolves than those of golden jackals. These wolf-like mtDNA sequences were confirmed to occur over a range 6,000 km wide, encompassing Algeria, Mali and Senegal. In both these studies, it was proposed to reclassify Canis aureus lupaster as a subspecies of Grey Wolf.

In 2015 however, a more thorough comparative study of mitochondrial and nuclear genomes on both Eurasian Golden Jackals and their African counterparts revealed that the latter were in fact a separate species more closely related to Grey Wolves and Coyotes, with a genetic divergence of around 6.7%, which is greater than that between Grey Wolves and Coyotes (4%) and that between Grey Wolves and domestic dogs (0.2%). 

It was estimated that the African golden wolf diverged from the wolf-coyote clade 1-1.7 million years ago during the Pleistocene, and that its superficial similarity to the Eurasian Golden Jackal(particularly in East Africa, where African wolves are similar in size to golden jackals) is a case of parallel evolution. Considering its phylogenetic position and the canid fossil record, it is likely that the African wolf evolved from larger-sized ancestors which became progressively more jackal-like in size upon populating Africa on account of interspecific competition with both larger and smaller-sized indigenous carnivores. Because of Egypt's contiguity with Israel, traces of golden wolf DNA were identified in Israeli golden jackals, thus indicating the presence of a hybrid zone.

Subspecies
As of 2015, MSW3 still classifies the six golden wolf subspecies as part of Canis aureus.

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 ten supposed West African subspecies were named or classed almost entirely because of their fur colour.

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.
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#2
Behaviour
Social and reproductive behaviours

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". Large groups are rare, and have only been recorded to occur in areas with abundant human waste. Family relationships among golden wolves are comparatively peaceful compared to those of the black-backed jackal; although the sexual and territorial behaviour of grown pups is suppressed by the breeding pair, they are not actively driven off once they attain adulthood. Golden 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. 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.

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 behaviour. 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 metres from the den, even sleeping in the open. Their playing behaviour 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.

The African wolf's life centres 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.

Communication
African wolves frequently groom one another, particularly during courtship, during which it can last up to ½ hour. 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 Jackals and Side-striped Jackals, being able to expose its canine teeth like a dog.

The vocabulary of the African wolf is similar to that of the domestic dog, with seven different sounds having been recorded. The African wolf's vocalisations include howls, barks, growls, whines and cackles. Different subspecies can be recognised by differences in their howls. 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, as well as establish territorial status.

Hunting behaviour
The African wolf rarely catches hares due to them being faster. 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.

Although it is known to kill animals up to three times its own weight, the golden wolves targets mammalian prey much less frequently than the Black-backed Jackal overall. 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. 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 by pouncing on them while they are on the ground or are caught in mid-air. 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.

Ecology
Diet

In West Africa, the African wolf mostly confines itself to small prey, such as hares, rats, ground squirrels and grass cutters. 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. In East Africa, it consumes invertebrates and fruit, though 60% of its diet consists of rodents, lizards, snakes, birds, hares and Thomson's gazelles. During the wildebeest calving season, African wolves will feed almost exclusively on their afterbirth. In the Serengeti and Ngorongoro Crater, less than 20% of its diet comes from scavenging.

Enemies and competitors
The African wolf tends to dominate smaller canid species, and has been observed to kill the pups of Black-backed Jackals. It often eats alongside African Wild Dogs, and will stand its ground if the dogs try to harass it. There is at least one record of an African wolf pack adopting a male Ethiopian Wolf.

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. Wolves will confront a hyena approaching too closely to their dens by taking turns in biting the hyena's hocks until it retreats.

Wolves in the Serengeti are known to carry the canine parvovirus, canine herpesvirus, canine coronavirus and canine adenovirus.




Cryptic African Wolf: Canis Aureus Lupaster Is Not a Golden Jackal

ScienceDaily (Jan. 26, 2011) — New molecular evidence reveals a new species of grey wolf living in Africa. Formerly confused with golden jackals, and thought to be an Egyptian subspecies of jackal, the new African wolf shows that members of the grey wolf lineage reached Africa about 3 million years ago, before they spread throughout the northern hemisphere.

As long ago as 1880 the great evolutionary biologist Thomas Huxley commented that Egyptian golden jackals -- then as now regarded as a subspecies of the golden jackal -- looked suspiciously like Grey Wolves. The same observation was made by several 20th Century biologists studying skulls. Nonetheless, the conventional taxonomy has not been changed. A new study, involving a collaboration of biologists from the University of Oslo, Oxford University's Wildlife Conservation Research Unit (WildCRU) and Addis Ababa University, has uncovered genetic evidence that unambiguously places the Egyptian jackal within the Grey Wolf species complex. It is not a jackal, but a wolf, taxonomically grouped with the Holarctic grey wolf, the Indian wolf and the Himalayan wolf. Dr Eli Rueness, the first author of the paper, states that "We could hardly believe our own eyes when we found wolf DNA that did not match anything in GenBank."

The genetic data indicate that the Indian and Himalayan wolves evolved as separate taxa within the modern wolf cluster even before the Grey Wolf radiated throughout the northern hemisphere. Furthermore, not only did these two types of wolves originate before Grey Wolves radiated in northern latitudes, but the wolfish colonization of Africa took place before the Grey Wolf radiation as well. The colonization of Africa by the ancestral stock of Grey Wolves took place about 3 million years ago and is today embodied by the animal that has hitherto been called the Egyptian jackal. Professor Claudio Sillero, of the WildCRU and current Chairman of the IUCN's Canid Specialist Group, added that "Ethiopian wolves split off from the Grey Wolf complex even earlier than the newly discovered African wolf."

The Oslo/WildCRU/Addis Ababa team also found genetically very similar specimens 2,500 km from Egypt, in the highlands of Ethiopia. Golden jackals are regarded by the IUCN (International Union for Conservation of Nature) as not endangered -- a "species of least concern" -- but the newly discovered African wolf may be much rarer. Certainly, it is a priority for both conservation and science to discover its whereabouts and numbers. Professor David Macdonald, an author of the paper and Director of Oxford's WildCRU, remarks that "A wolf in Africa is not only important conservation news, but raises fascinating biological questions about how the new African wolf evolved and lived alongside not only the real golden jackals but also the vanishingly rare Ethiopian wolf, which is a very different species with which the new discovery should not be confused." It seems that the Egyptian jackal is urgently set for a name-change, and its unique status as the only member of the Grey Wolf complex in Africa destines it to be re-named the African wolf.

According to Professor Nils Chr. Stenseth, an author of the paper and the Chair of the Centre for Ecological and Evolutionary Synthesis (CEES), "This study shows the strengths of modern genetic techniques: old puzzles can be solved." "This shows how genetic techniques may expose hidden biodiversity in a relatively unexplored country like Ethiopia," concludes Professor Afework Bekele at Addis Ababa University.

--------------------------------------------------------------------------------

Journal Reference:

Eli Knispel Rueness, Maria Gulbrandsen Asmyhr, Claudio Sillero-Zubiri, David W. Macdonald, Afework Bekele, Anagaw Atickem, Nils Chr. Stenseth. The Cryptic African Wolf: Canis aureus lupaster Is Not a Golden Jackal and Is Not Endemic to Egypt. PLoS ONE, 2011; 6 (1): e16385 DOI: 10.1371/journal.pone.0016385
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#3
Red Dog Wrote:Source: Jane Goodall and Hugo Van Lawick, Innocent Killers

Adult male golden jackal ("Jason") drives off "huge" lappett faced vulture who stole meat from golden jackal pup ("Rufus")

[Image: GoldenJackalChasesoffHugeLappettFacedVulture.jpg]

MightyKharza Wrote:... 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 is 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 reasons 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, George (1890), Dogs, Jackals, Wolves and Foxes: A Monograph of the Canidæ, R.H. Porter, London, pp. 36-37
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#4
'Golden jackals' of East Africa are actually 'golden wolves'

Date: July 30, 2015
Source: Cell Press
Summary:
Despite their remarkably similar appearance, the 'golden jackals' of East Africa and Eurasia are actually two entirely different species. The discovery, based on DNA evidence, increases the overall biodiversity of the Canidae -- the group including dogs, wolves, foxes, and jackals -- from 35 living species to 36.

[Image: 150730130727_1_900x600.jpg]
A golden jackal (Canis aureus) from Israel. Based on genomic results, the researchers suggest this animal, the Eurasian golden jackal, is distinct from Canis anthus, which they propose be referred to as the African golden wolf.

Despite their remarkably similar appearance, the "golden jackals" of East Africa and Eurasia are actually two entirely different species. The discovery, based on DNA evidence and reported in the Cell Press journal Current Biology on July 30, increases the overall biodiversity of the Canidae--the group including dogs, wolves, foxes, and jackals--from 35 living species to 36.

"This represents the first discovery of a 'new' canid species in Africa in over 150 years," says Klaus-Peter Koepfli of the Smithsonian Conservation Biology Institute in Washington, DC.

The new study, led by Koepfli and Robert Wayne of the University of California, Los Angeles, was inspired by recent reports suggesting that the African golden jackal was actually a cryptic subspecies of gray wolf. Those studies were based on an analysis restricted to mitochondrial DNA, which is passed along via the maternal lineage.

To expand the DNA evidence in the new study, Wayne retrieved DNA samples of golden jackals collected two decades ago in Kenya from his laboratory freezers. Koepfli and Wayne also established collaborations with colleagues, who provided them with samples from golden jackals in other parts of Africa and Eurasia. That genome-wide DNA evidence told a different story of the canids' evolutionary past.

"To our surprise, the small, golden-like jackal from eastern African was actually a small variety of a new species, distinct from the gray wolf, that has a distribution across North and East Africa," Wayne says. The researchers have named this previously unrecognized species the African golden wolf.

Koepfli and Wayne suspect that zoologists had mistaken African and Eurasian golden jackals for the same species because of a high degree of similarity in their skull and tooth morphology. However, the genetic data supports the idea that they are in fact two separate lineages that have been evolving independently for at least a million years. In fact, the new canid family tree suggests that these two lineages aren't even closely related. The African species is more closely related to the lineage leading to gray wolves and coyotes than jackals, which explains their new designation as African golden wolves.

The findings come as a reminder that "even among well-known and widespread species such as golden jackals, there is the potential to discover hidden biodiversity," with the help of genomic evidence, Koepfli says. The researchers say they will continue to study the relationships among golden jackal and wolf lineages in Africa, Eurasia, and the Middle East.

Story Source: Cell Press. "'Golden jackals' of East Africa are actually 'golden wolves'." ScienceDaily. www.sciencedaily.com/releases/2015/07/150730130727.htm (accessed July 31, 2015).




Journal Reference:
Klaus-Peter Koepfli, John Pollinger, Raquel Godinho, Jacqueline Robinson, Amanda Lea, Sarah Hendricks, Rena M. Schweizer, Olaf Thalmann, Pedro Silva, Zhenxin Fan, Andrey A. Yurchenko, Pavel Dobrynin, Alexey Makunin, James A. Cahill, Beth Shapiro, Francisco Álvares, José C. Brito, Eli Geffen, Jennifer A. Leonard, Kristofer M. Helgen, Warren E. Johnson, Stephen J. O’Brien, Blaire Van Valkenburgh, Robert K. Wayne. Genome-wide Evidence Reveals that African and Eurasian Golden Jackals Are Distinct Species. Current Biology, 2015; DOI: 10.1016/j.cub.2015.06.060

Highlights
•African and Eurasian golden jackals are genetically distinct lineages
•Divergence between lineages is concordant across multiple molecular markers
•Morphologic convergence is observed between African and Eurasian golden jackals
•African golden jackals merit recognition as a distinct species

Summary
The golden jackal of Africa (Canis aureus) has long been considered a conspecific of jackals distributed throughout Eurasia, with the nearest source populations in the Middle East. However, two recent reports found that mitochondrial haplotypes of some African golden jackals aligned more closely to gray wolves (Canis lupus), which is surprising given the absence of gray wolves in Africa and the phenotypic divergence between the two species. Moreover, these results imply the existence of a previously unrecognized phylogenetically distinct species despite a long history of taxonomic work on African canids. To test the distinct-species hypothesis and understand the evolutionary history that would account for this puzzling result, we analyzed extensive genomic data including mitochondrial genome sequences, sequences from 20 autosomal loci (17 introns and 3 exon segments), microsatellite loci, X- and Y-linked zinc-finger protein gene (ZFX and ZFY) sequences, and whole-genome nuclear sequences in African and Eurasian golden jackals and gray wolves. Our results provide consistent and robust evidence that populations of golden jackals from Africa and Eurasia represent distinct monophyletic lineages separated for more than one million years, sufficient to merit formal recognition as different species: C. anthus (African golden wolf) and C. aureus (Eurasian golden jackal). Using morphologic data, we demonstrate a striking morphologic similarity between East African and Eurasian golden jackals, suggesting parallelism, which may have misled taxonomists and likely reflects uniquely intense interspecific competition in the East African carnivore guild. Our study shows how ecology can confound taxonomy if interspecific competition constrains size diversification.

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http://www.cell.com/current-biology/abstract/S0960-9822(15)00787-3?_returnURL=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0960982215007873%3Fshowall%3Dtrue




Golden jackal: A new wolf species hiding in plain sight
A new species of wolf has been discovered in Africa after exhaustive DNA and morphological analyses revealed it is evolutionarily distinct from the Eurasian golden jackal, which it strongly resembles


[Image: Golden%20Jackals%201_zps7e4fkuxs.jpeg]
Same or different? The African golden wolf, Canis anthus, (left) and Eurasian golden jackal, C. aureus (right), were originally thought to be the same species, formerly known as the golden jackal.

Friday 31 July 2015 02.02 AEST Last modified on Friday 31 July 2015 02.39 AEST

The Canid family -- wolves, coyotes, jackals, foxes, domestic dogs and others -- are so familiar to us, and have been so intensively studied for so long that you might think that we know almost everything there is to know about them. But a paper published today in Current Biology belies that assumption. This paper describes the meticulous research conducted by an international team of experts who report a surprising discovery: a new species of wolf.

According to the authors, two golden jackal populations -- one in Eurasia and the other in Africa -- split more than one million years ago, which is sufficient to formally recognise each as separate species. Further, after exhaustive DNA analyses, the authors were surprised to learn that African golden jackals are more closely related to grey wolves, even though there are no grey wolves in Africa and even though grey wolves and African golden jackals look dramatically different. Adding to the confusion, African golden jackals are strikingly similar in appearance to their more distant relative, the Eurasian golden jackal. This strong physical similarity has long been the source of confusion over these animals’ taxonomy and evolutionary relationships.

As a result of this study, the authors propose that the African golden jackal be renamed as the African golden wolf, Canis anthus.

The evolutionary relationships of canids are poorly understood
The evolutionary relationships, or phylogenetics, of jackals have long been a mess, according to Adam Hartstone-Rose, an Associate Professor of Cell Biology and Anatomy at the University of South Carolina School of Medicine, who was not part of the study. Traditionally, most taxonomists have recognised three jackal species: the black-backed, side-striped and golden jackals -- all of which live in Africa, with the golden jackal also ranging throughout much of Eurasia.

“The three ‘species’ were considered close relatives based mostly on their similar body size and morphology”, explained Professor Hartstone-Rose in email.

“However, as the first molecular analyses of canids became available, it was obvious that ‘jackals’ are only similar based on amazing morphological convergences”, said Professor Hartstone-Rose. “The side-striped and black-backed species (historically called Canis adustus and C. mesomelas respectively) turn out to have split off of the stem of the large Canis group before the highly derived hunting dogs (Lycaon) and dholes (Cuon).”

Two earlier studies reported that golden jackals found in Africa are more closely related to grey wolves than to the golden jackals found in Eurasia (doi:10.1371/journal.pone.0016385 & doi:10.1371/journal.pone.0042740). These studies inspired Klaus Koepfli, a Research Associate and Visiting Scientist at the Center for Species Survival (CSS), which is part of the Smithsonian Conservation Biology Institute, to investigate more thoroughly.

“Those studies had only used one kind of genetic marker, sequences from the mitochondrial genome, which are only inherited through the maternal lineage”, explained Dr Koepfli in email.

“[E]volutionary history is best verified through concordance among genetic markers from across the genome that are inherited maternally, paternally and bi-parentally and that evolve at different rates to capture different stages of divergence. Therefore, we wanted to test the conclusions of the two previous studies by adding data from the nuclear genome”, said Dr Koepfli.

African and Eurasian golden jackals are genetically distinct
The researchers started by generating new sequence data (sampling sites are indicated with red dots in Figure 1B) for canid cytochrome b, a gene in the mitochondrial genome, and combined them with sequences from the two previously published studies (doi:10.1371/journal.pone.0016385 & doi:10.1371/journal.pone.0042740). Their analysis of these data incorporated a total of 104 cytochrome b sequences (1,140 bp each) to reconstruct a phylogeny (Figure 1A), for golden jackals from both Africa and Eurasia:

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Figure1. Phylogenetic Tree (A) Based on Mitochondrial Cytochrome b Sequences & Sampling Localities (B) of Golden Jackals in This Study. Maximum-likelihood phylogram of 104 cytochrome b sequences (1,140bp). Asterisks nodes indicate bootstrap support ≥80% (1,000 pseudoreplicates) and ≥0.95 posterior probability (Bayesian inference). Arrows: Canis spp. from Egypt. African wolf is Canis lupus lupaster. Outgroup: Sechuran fox, Lycalopex sechurae. Photo credits: L, golden jackal from Senegal (CIBIO/Raquel Godinho); C, Mexican gray wolf (Tom & Pat Leeson); R, golden jackal from Israel (Yaki Zander). Composite: Klaus-Peter Koepfli & John Pollinger et al./Current Biology 2015

“Consistent with two previous studies also based on mitochondrial sequences, we find that golden jackals from Africa and Eurasia are NOT each other’s closest relative as we would expect if they were the same species”, said Dr Koepfli. 

This mitochondrial gene tree indicates that the African golden jackal is more closely related to the Eurasian gray wolf, and is distantly related to the Eurasian golden jackal (with up to 6.7 percent divergence).

“In fact, golden jackals from different localities in Africa share a more recent common ancestry with gray wolves”, said Dr Koepfli.

The team then conducted another analysis using a more comprehensive array of molecular markers that are inherited from both parents. All of these DNA markers consisted of fragments of 20 chromosomal, or nuclear, genes sampled from throughout the genome. These markers consistently showed that golden jackals are separated into two well-supported clades, as seen in this time tree, or chronogram (Figure 2):

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Figure 2. Chronogram Estimated from Concatenated Analysis of 20 Nuclear Gene Pieces Using a Relaxed Molecular Clock. Analysis of 13,727bp sequence from 17 intron- & 3 exon-containing pieces. 4 individuals each for gray wolf, golden jackal (Africa) & golden jackal (Eurasia); 2 individuals for coyote. Outgroups: red fox, Vulpes vulpes, & gray fox, Urocyon cinereoargenteus. Time (bottom): million years ago (mya), time (top): epochs. Photo credits: top, Mexican gray wolf (Tom & Pat Leeson); middle, golden jackal from Senegal (CIBIO/Raquel Godinho); bottom, golden jackal from Israel (Yaki Zander). Composite: Klaus-Peter Koepfli & John Pollinger et al./Current Biology 2015

In addition to showing the family relationships between the species examined, this chronogram shows an estimate of the sequence of those speciation events, or lineage splits, in the order in which they occurred and when.

“We found that the African golden jackal lineage split from gray wolves plus coyotes about 1.3 million years ago. The Eurasian golden jackal lineage, however, split about 600,000 years prior to that”, said Dr Koepfli.

Not only does the chromosomal (nuclear) DNA data phylogeny suggest a close relationship between African golden jackals and grey wolves, but if you look carefully, you will also notice that it indicates that the Eurasian golden jackal split away from from the grey wolf long before grey wolves and coyotes diverged.

“If African and Eurasian golden jackals belonged to the same species, we would expect these two groups to be more closely related (share common ancestry)”, said Dr Koepfli.

Multiple DNA markers show African and Eurasian golden jackals are different
The researchers continued their investigation by analysing additional molecular markers: sex chromosome sequences (Figure 3A); tiny variations in the DNA sequence known as single nucleotide polymorphisms (SNPs; pronounced “snips”) sampled from across the genome in representative individuals (one golden jackal from Kenya, one golden jackal from Israel and three grey wolves from different localities in Eurasia) (Figure 3B); and in microsatellites (long tracts of non-coding DNA comprised of short tandem repeating sequences), which are DNA markers that represent different samples of the genome from SNPs and which evolve differently than SNPs (Figure 3D):

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Figure3. Patterns of Genetic Differentiation and Admixture of African and Eurasian Golden Jackals Based on (A) Sex Chromosome Sequences, (B) Genome-wide SNP Data, © Detectable admixture (gene flow) between lineages and (D) Microsatellite Multilocus Genotypes. Illustration: Klaus-Peter Koepfli & John Pollinger et al./Current Biology 2015

Once again, every genetic marker that the team examined consistently showed that the two golden jackal lineages are genetically distinct and are following independent evolutionary trajectories -- which are several of the main criteria for defining a species.

“The consistency of divergence between the two jackal lineages across the suite of molecular markers used in our study provides compelling evidence that the two lineages represent different species”, said Dr Koepfli.

The research team also tested genome-wide SNPs data to see whether African and Eurasian golden jackals show evidence of hybridisation with each other, or with wolves and dogs (Figure 3C).

“[W]e did detect signals of hybridization between the gray wolf/domestic dog lineage and the Eurasian golden jackal and African golden wolf lineages. However, that signal was much stronger in the Eurasian golden jackal lineage”, said Dr Koepfli.

“The individual we used for the genome-wide data came from Israel, where these golden jackals overlap with gray wolves and (feral) domestic dogs, so finding a strong signal of past hybridization is not too surprising”, said Dr Koepfli.

But African and Eurasian golden jackals look very very similar
Despite their distinct genetic ancestries, African and Eurasian golden jackals look so much alike that most scientists classified them as the same species. Thus, the research team wanted to see if their genetic findings were reflected in the skull and tooth morphologies of African and Eurasian golden jackals. They analysed 45 different skull and tooth characteristics from more than 140 golden jackals from five different geographic regions across Africa and Eurasia (east Africa = red circles; north African = green circles; Middle East = blue triangles; Eurasia = grey triangles; central and west Africa = grey circles; Figure 4A):

As you can see above, there are no distinct clusters of data, as you would expect if there were significant species-based differences in skull and tooth morphologies.

Analyses of these morphometric data revealed that despite their genetic distance, the golden jackals have a strong resemblance to each other, as revealed by these overlapping data clusters (east Africa = red circles; north African = green circles; Middle East = blue triangles; Figure 4B). These data certainly explain the difficulty in recognising golden jackals as separate species:

But why do these two species look so much alike that they fooled almost everyone for hundreds of years?

“Since the two jackal lineages are not closely related, this morphological similarity may be due to parallel evolution, driven by the ecological circumstances in which these animals live, especially with regards to the competition from other carnivore species”, said Dr Koepfli.

Parallel evolution is the development of a similar trait in related, but distinct, species that share a common ancestor. This differs from convergent evolution, where species with different evolutionary histories independently evolve traits that are similar in form or function (such as wings in flying insects, bats and birds) due to similar ecological demands.

Jackals may have more surprises in store for us
Since they have such an extensive range, golden jackals may comprise yet more cryptic species. Already, Dr Koepfli and his team are collecting preliminary genetic data from some populations of Eurasian golden jackals throughout Eurasia and they plan to do the same for the African golden jackals.

“Some of the data we present in the Current Biology paper suggests that the Kenyan population is genetically distinct across both mitochondrial and nuclear markers”, said Dr Koepfli.

“However, we need more comprehensive geographic sampling to better understand the population genetics and phylogeography of the two lineages.”

The golden jackals are only distantly related to the other two African jackal species, even though they are all placed into the same genus.

“In fact, phylogenetic results of nuclear DNA sequences shows that black-backed and side-striped jackals are each other’s closest relative and very distant from Eurasian golden jackals and African golden wolves”, said Dr Koepfli.

“All these are currently classified in the genus Canis, but this needs to be changed to reflect the distinct position of the clade that includes black-backed and side-striped jackals. This is something we’re currently working on.”

African golden jackals renamed African golden wolves
This painstaking work shines a powerful light on the convoluted relationship between ecology and evolution, and reveals how ecology can lead to confusion amongst even the most astute experts when it comes to identifying species. Further, these findings demonstrate why it is critical to analyse living species from all perspectives -- anatomic, behavioral, ecological and genetic -- in order to truly understand the evolution of those species.

“This study demonstrates convincingly, using multiple lines of genomic evidence, that African and Eurasian golden jackals represent distinct lineages deserving of species-level separation”, said vertebrate paleontologist Jack Tseng from the American Museum of Natural History, who was not part of this study.

“The fascinating conclusion of parallelism in the African and Eurasian jackals gained from considering both molecular and anatomical evidence attests to the success of dogs such as Canis in colonizing and adapting to new environments”, said Dr Tseng.

“Within eastern Africa where I do most of my work, all canids (not just golden jackals) are relatively rare in the fossil record. Therefore, this study provides us with an intriguing glimpse of carnivore evolution that we might not otherwise know about”, said vertebrate paleontologist, Margaret Lewis, a Professor of Biology at Stockton University, who was not part of this study.

This research also has important conservation implications. For example, as established here, one widespread species may actually be several cryptic species.

“What if your two new species represented vastly different percentages of the former species? One of the new species could be doing relatively well while the other population is on the verge of extinction”, said Professor Lewis in email.

Currently, golden jackals (Eurasian and African) are listed by the IUCN as of Least Concern, but this assessment was made in 2008, before any of the recent genetic work on this group.

“While they are considered to be fairly common (particularly in Asia), it will be interesting to see if African golden wolves and Eurasian golden jackals will each retain this ranking in the next assessment. Jackals in general are declining as traditional land use practices disappear and are replaced by industrialization and urbanization. All jackals and jackal-like animals, not just African golden wolves, play a critical role in the ecology of their respective habitats”, said Professor Lewis.

“Hopefully, this research will raise awareness of the importance of jackals and similar species around the world before it is too late”, said Professor Lewis.

Taken together, these remarkable findings provide strong and compelling evidence that the African golden jackal represents the first discovery of a canid species in Africa that is new to science in over 150 years.

“We propose that the African golden jackal be re-named the African golden wolf and the scientific name be Canis anthus,” said Dr Koepfli.

This scientific name was first proposed in 1820 by Frédéric Cuvier in his description of this species.

http://www.theguardian.com/science/grrlscientist/2015/jul/30/golden-jackal-a-new-wolf-species-hiding-in-plain-sight 
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