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Posts Tagged ‘black-backed jackal’

golden wolf vs. black backed jackal

Not the best photo, but this is golden wolf on the left and a black-backed jackal on the right. I screen-captured this image from this documentary, which was made before the big golden jackal revision that happened a few years ago.

There is still a big debate on how classify the creature formerly known as the African golden jackal. It is clearly closer to gray wolves and coyote than to the Eurasian golden jackal, but the exact closeness requires further research.

The black-backed jackal on the right is a much older species. It has been known from the fossil record in Africa for over two million years, and the wolf-coyote-golden wolf lineage last shared a common ancestor with it around 4.5 million years ago.

Depending upon when we finally determine when the golden wolf diverged from the modern gray wolf, it may have evolved from larger ancient gray wolves that adapted to fit the generalist jackal-like niche, or it may have evolved from a African population of Canis mosbachensis.

The black-backed jackal is derived from the earliest wolf-like canids to have entered the Old World from North America. Those early wolves were all smaller and jackal-like, and its appearance and adaptations are of the primitive type.

So here we have two species that look like they might just be color phases of the same species but actually are divided by millions of years of evolution. One is a truly primitive member of its lineage. So primitive and basal that its now classified in a different genus (Lupullela). The other came from a more derived source that evolved parallel characteristics with the primitive one.

Parallel evolution is a hell of a thing, especially when it comes to canids. So much of this parallel evolution has been missed in paleontology and in the conventional methods of taxonomy that use only morphology. Not recognizing the parallel evolution issues is why we didn’t notice that coyotes and gray wolves were much more closely related than we ever could have imagined. It’s also why we thought bush dog belonged with the dhole and African wild dog, just because their teeth are so similar, and it is also why an affinity has been suggested between crab-eating foxes and raccoon dogs, even though they are in entirely different lineages. It is also why there was a suggestion that red wolves represent an ancient lineage of North American wolves, when they are now probably hybrids between coyotes and gray wolves.

Parallel evolution messes up a lot of things. Our eyes and our measuring instruments can fail us.

But the correction of these failures reveals a much more mysterious world.

That’s the inherent beauty of science. Each correction is a revelation.

 

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Corrections: arctic foxes are born in brown or bluish black summer pelts and arctic wolves are born gray.

These are of the Cape species or subspecies (depending upon how you accept the most recent genetic studies on them), and yellow ones have also been spotted in the Kalahari.

 

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cape vs east african

Cape jackal  (L) and East African black-backed jackal (R)

The molecular revolution in biology has caused a great deal of turmoil in the taxonomy of Canids. Long-time readers know that full-genome comparisons have recently found that the red wolf and Eastern wolf are hybrid between coyotes and wolves, and one implication of the recent origins of the coyote is that the coyote itself might be better classified as a subspecies of wolf. 

Mitochondrial DNA comparisons, though potentially erroneous in determining the exact time of divergence between species or subspecies, have also revealed that the “golden jackals” of Africa are much more closely related to wolves than Eurasian golden jackals.  Classifying African golden jackals is going to take more analysis of their genome, but they are either a species on their own or a subspecies of wolf. They have evolved in parallel with both the Eurasian golden jackal and the coyote.

We also know now that the red fox of the Old World is quite divergent from that of North America, enough that some authorities are reviving the old Vulpes fulva for the North American species.  Red foxes in the Eastern and Midwestern US are actually part of this endemic North American species and are not, as the folklore claimed, to be derived from seventeenth and eighteenth century introductions from England.

Recent mitochondrial DNA analysis also revealed that Eastern and Western gray foxes are perhaps separated by 500,000 years of evolution. 

So we’ve likely lost two wolf species in North America. The coyote’s validity is questionable. But we’ve gained either a wolf species or subspecies in Africa.  We have also potentially gained two species of fox in North America.

With all of these new findings in DNA studies, scientists are looking more and more closely at other long-established species.

Last week,  a study of the cytochrome b gene of black-backed and side-striped jackals revealed that these jackals, too, have some secrets.  Cytochrome b genes are part of the mitochondrial genome.

At one time these animals were considered part of Canis, but the current trend is to classify them in their own genus (Lupulella).* They are quite divergent from the rest of the wolf-like canids, much more so than dholes and African wild dogs are. If dholes and African wild dogs are in their own genera, then it makes sense that these two jackals should have their own genus name.

But if they are that divergent from the rest of Canis, then it’s very possible that there are other secrets, and this limited mtDNA study certainly raises some important questions.

The researchers found that the Cape subspecies and East African subspecies of the black-backed jackal (Lupulella mesomelas) actually diverged 2.5 million years ago.

I’ve always thought that there was a possibility of these two jackals being distinct species. The East African black-backed jackal has a shorter muzzle, comparatively larger ears, and usually lack the dense coat of the Cape jackal. The Cape jackal reminds me very much of Southwestern forms of coyote, with longer muzzle and thicker fur. What’s more is that the Cape jackal comes in a white and a golden phase that are not seen in the East African black-back.

If this deep divergence is confirmed in the full-genome or simple nuclear DNA studies that are very likely to be performed, then we likely have two species of what are called black-backed jackals now.

The researchers also found through this same analysis that the West African side-striped jackal diverged from the other two populations 1.4 million years ago, which certainly would raise some questions about its species status as well.

Again, we’re going to have to wait until full-genome analyses are performed, but I’ve always suspected that there are more than two species of endemic African jackal possessed some cryptic species.  I also have suspected that both side-striped jackals and black-backed jackals have hybridized a bit. This speculation could be revealed through the same full-genome or nuclear DNA studies that could examine the taxonomy within these supposed species.

Finally, the distribution of black-backed jackals is disjointed. The East African and Cape variants are separated by 800 miles. Several other small carnivorans have a similar distribution. The bat-eared fox and the aardwolf have disjointed distributions in which one population is in East Africa and the other in Southern Africa. It is very possible that similar deep genetic divergence exists within these species as well.

These potential cryptic species are worth investigating, and they certain put some of these “red wolf” controversies with in proper perspective.  If that 2.5 million-year divergence is upheld within the black-backed jackal populations, it really does become hard to justify the red wolf.  It is descended from two putative “species” that really aren’t that divergent at all by comparison.

 

 

 

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*A bit errata:  I initially called the new scientific name of the side-striped jackal Lupulela adustus, which is just a modification of Canis adustus.  Most of the literature I’m corrects the gender to Lupulella adusta.

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lupullela adustus

Lupullela adusta, new name for the side-striped jackal. 

As we have examined the genomes of various  dog species, one problem has become evident:   The genus Canis is paraphyletic. Two endemic African jackals, the side-striped and black-backed jackal, are actually more distantly related to the wolf-like canids than the African wild dog and dhole are.

One way to solve this problem would be to make the dhole and African wild dog part of Canis, but the problem with this classification remedy is that the paleontology on the dhole and African wild dog is quite hard to trace and still fairly controversial. Anything in their lineage needs to have different classification in order to keep those specimens distinct from the main wolf-like canid clade.

The other solution is to give the black-backed and side-striped jackals their own genus.  In the early part of the twentieth century, it was common to refer to these species within a genus called Lupullela. I’ve noticed that a few papers have popped up using this genus, like this one that examines which predatory species may have left the remains of quarry in a Late Pleistocene cave in Morocco.

I don’t think it will be very long before both the side-striped and black-backed jackal will be commonly referred to as Lupullela.

I won’t be complaining. Paraphyly is something I find annoying.  We are classifying nature in light of evolution, and making sure we have true clades in which animals are classified according to their common descent is important.

The classification of jackals is undergoing a sea change. The creature known as the golden jackal is two species, but the exact way to classify the two species is still hotly contested.  The African “golden jackal” is closer to the wolf and coyote than the Eurasian “golden jackal,” but we don’t have good full-genome data to place the African golden jackal properly. It could wind up that the African golden jackal is very close to the wolf, as the coyote was recently found to be, and this will make the actual classification really touchy.

But that current debate is nothing compared to the way we are starting to classify the two divergent jackals of Africa. These animals don’t get studied as much, but I would highly suspect that there are surprises hidden in their genomes. It could be that there are actually several species currently classified as black-backed and side-striped jackals, and it is also highly likely that there are hybrids among these forms as well as between the species classified currently as side-striped and black-backed jackals.

Neither jackal is endangered, but they are something different, something that is at least worthy of study.

These are sort of forgotten dogs, and their secrets are only now just coming to light.

 

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dire wolf mesomelas

It was always assumed that the dire wolf and its kin, the endemic extinct North American wolves, were very closely related to modern wolves.

However, the genome of the dire wolf was just sequenced by a team of independent researchers at the Russian Institute of Cytology in Saint Petersburg.  The team of geneticists and paleontologists was led by Boris Yudin. The team wanted to have access to the remains of dire wolves at Rancho La Brea, but they were instead able to obtain access to several skeletons that were being held at the Indiana Museum of Natural History.

“It was very hard to get access to the specimens,” says Yudin,  who has always been fascinated by Pleistocene North American megafauna, “But once we did get access, the DNA sequences were quite easily obtained from the shoulder bones.”

“We were able to get one full genome sequenced, and then we began to compare this genome with other species in the genus Canis,”  says Yudin, “and using a Bayesian analysis, we were quite shocked to learn that the dire wolf wasn’t really a wolf at all.”

Most paleontologists had believed that the dire wolf was a sister species to the modern gray wolf, and if this assumption were true,  the dire wolf genome would be most similar to this species.

However, the dire wolf didn’t share an affinity with the gray wolf. Instead, it shared a much stronger relationship with the black-backed jackal, a species of canid found in East and Southern Africa, which is quite genetically distant from other wolves and jackals.

“There is even a debate as to whether the black-backed jackal even properly belongs in Canis,” says Yudin, “It is so genetically divergent.  But our research found that the dire wolf and the black-backed jackal are sister tax.”

Using the genetic differences between the dire wolf and the black-backed jackal to calculate when they last shared a common ancestor,  Yudin’s team estimated that the two species split only about a million years ago. Black-backed jackals and their current living closest relative, the side-striped jackal, are believed to have diverged from the rest of Canis some 5 million years ago, and the same is true of the dire wolf.

“The two divergent African jackals and the dire wolf form a clade, and if we are to classify the  two jackals outside of Canis, then the same will have to be done with the dire wolf,” Yudin points out.

“Within the dog family, the tendency towards parallel and convergent evolution cannot be underestimated.  We now know there are jackals and wolves that exist now and have existed that come out of divergent lineages. This is the most important discovery,” says Yudin.

So now we have the golden wolf of Africa, which is a convergent form of jackal out of the wolf lineage, and we have the extinct dire wolf, which was a divergent jackal that evolved into a wolf.

Yudin’s team plans on extracting the genome of the Armbruster’s wolf, which is conventionally believed to have been the direct ancestor of the dire wolf.  If this is true, then the Armbruster’s wolf will also share an affinity with the black-backed jackal.  The team also is beginning an analysis of Pleistocene coyote genomes from across the United States.

“It is an amazing time, ” says Yudin. “Many discoveries to be made.”

Disclaimer:  Please do not post this story as authoritative until reading this post that acts as a follow-up. 

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Trained black-backed jackal

I might sound weird, but if I ever go to Africa, this is the first species I want to see:

 

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hybrid

The scent of canid estrus wafts out of the clouds of the Harenna Forest in Ethiopia’s Bale National Park. It floats out of the wet jungle into the land of lichens that lies way up high in the Sanetti Plateau, where he smells it.

He stops to savor the scent, which is almost like that of his mother and sisters but not exactly.

Yet is strangely beguiling.

His kind are the red-coated “wolves” of the Ethiopian Highlands. They are Africa’s rarest canid and may be the rarest of all wild dogs. They spend their days hunting big-headed mole-rats and other rodents. They are rare and found only in these Afro-Alpine lands of Ethiopia.

His kind stay in the open moorland of lichens. They don’t wander down in the cloud forest. That is the realm of the black leopard, the creature that savors the taste of dog-flesh above all others and would love nothing more than to swipe an arrogant little tawny wolf.

But the smell is strong, and the last few months have been hectic in his pack. The bitches have all come in estrus, and his mother ran off his older sisters. By the law of Ethiopian wolves, only one bitch produces a litter and that one bitch is the sole mate of a single male.

Thus, our wolf friend has spent a long time smelling the beguiling fragrance of estrus but never getting a chance to partake in any mating.

This smell isn’t quite the same, but it’s so similar that he can’t help be drawn to it.

He abandons his caution and wanders down into the clouds. He soon finds himself in the wet jungle of the Harenna Forest. Moss lies hard upon the trees.Strange little monkeys chatter among the bamboo.

And the scent grows stronger.

He keeps following his canine  concupiscence through this strange world. For a creature so devoted to living in the open moorland, this jungle is a terrifying alien landscape. The buzzing of insect causes him to jump. The gentle falling rain upon the leaves vexes him.

Hunger soon begins set in, but just as he’s about to turn around and head home, he catches wind of some decaying meat.

He follows his nose and soon finds himself looking at the remains of a bushbuck. He also smells the odor of a cat of some sort, but it has long since passed. But smells another odor. It almost like that of his own kind but not quite.

He is in the land of strange wolves, and his hackles are raised.

He knows he might have to fight for a bit of food, but he doesn’t know who these strangers are.

He eats a bit of the meat and raises his head to scan the undergrowth. He must eat, yet he is terrified.

He hears the approach of canine steps. He bristles. The time for a fight is now!

Then the beguiling scent of estrus fills the air. The hackles go down. He doesn’t consciously realize that he’s becoming softened.

The sound of canine steps grows stronger. They stop. Then they grow stronger again.

Then out from behind a stand of kokisa trees comes the creature. Our wolf notices that this is source of the beguiling estrus odor, and though he was expecting a strange Ethiopian wolf from another pack, she not one.

But in some ways she is.

She is almost entirely gray with black hairs mixed in. Along the sides of her back the pelt mixes in such a way as to form two stripes, each running from her shoulder to her hip. Her tail is tipped in white.

She is a side-striped jackal.  Her kind is numerous. They are found throughout Africa south of the Sahara and the Sahel. They are creatures of the brush and thicket. Their kind almost never makes it onto nature documentaries.

They are that banal, that common, that no one would would waste time filming a den-site or extolling their virtues.

Our two creatures stare at each other over the bushbuck carrion. Neither knows what to make of the other. 3 or 4 million years of evolution separate the two species. One is a specialist of an ecosystem that is dying. The other is a generalist of tropical Africa.

But the genetic difference between the two is trivial at this moment.

The young jackal bitch has been driven from her parents’ territory.  She is too defiant of her mother over the kills they scavenge, and her mother just can’t handle such recalcitrance. Estrus made the situation worse, for in jackal society, only one bitch and one dog mate and have the pups. Her sister accepted her mother’s edicts that only she would mother pups, but our jackal bitch fought back and tried to mate with her brother and then her father.

One big fight ensued, and now our jackal bitch is running through the forests, alone and in estrus. She has no territory, and no other dog jackals from other families have courted her.

Her desire to mate is strong now.  And though she’s has been eating off this old leopard kill– one that the old leopard decided wasn’t worth hauling up into the trees– she hasn’t been herself at all.

On her old leopard kill stands a jackal of sorts. He’s bigger than any jackal she’s seen before. He smells different, but he also smells good.

Part of her says to approach. Part of her says to flee. The former is pushing her forward, and as the wolf’s face begins to soften, she feels at ease.

She approaches the red stranger. They touch noses. She backs off.  He wolf-grins. She pounces at him playfully. He backs off. They stare at each other again.

The ritual goes on for an hour. They begin to forget what they are. The strangeness of the moment becomes an odd sort of familiarly.

She licks his lips. He licks hers.  He stands proudly with his ears back. She playfully paws him.

They smell each other.

She spins around and puts her tail to the side. He mounts. There is a tie.

For three days the eat from the bushbuck carcass and mate in the jungle. She alerts him to the scent of the leopard and shows him how much fun it is to chase monkeys into the trees.

On the evening of the third day, the young wolf stoops to drink from a puddle. The black leopard springs from behind a bush and is on the wolf before he knows it. The leopard doesn’t know that he has killed a rare wild dog. He’s caught a big jackal, and jackal meat is so tasty that he has to take it up into the canopy for storage.

The jackal bitch goes looking for her mate. She barks and howls into the night. There is no answer.

An old male side-striped jackal who hasn’t had a mate for year finds her. She still smells of estrus, so she is accepted by him. The two jackals wander off into the darkness. They mate one time, but the two remain together as mates. Within her grow the whelps, one of which is sired by the old male jackal, and the other is the hybrid with the Ethiopian wolf suitor.

The pups are born in the den she digs. One pup is a typical side-striped jackal, while the other is marked with tan points and a black tail with no white tip. The hybrid grows up as a jackal, though she is clearly different.

One day, a group of researchers comes across her and takes her photograph. Then they take many photos.

She is so strange that the researchers believe she is new species of jackal. When her photos are posted online, a lot of debate develops about what she is. Is a new species?  Is she a hybrid of golden jackal (now a golden wolf) and side-striped jackal?  Is she a  hybrid of Ethiopian wolf and dog?  Ethiopian wolf and side-striped jackal?  Nah. She’s an unusual side-striped jackal without the stripes or the white-tail tip.

And the mystery jackal roams the Harenna Forest. The debate goes on.

This is the story of a hybrid.

***

The above is an entirely fictitious account of what might have happened to produce the unusual jackal in the photograph above. The current consensus— based upon looking at the many photos taken of the creature– is that she is an unusual side-striped jackal.

The truth is this debate really can’t be settled definitely. We have no DNA samples from the beast.

But the possibility of other hybrids beyond the usual subjects in the genus Canis has long fascinated me. It could happen. It just hasn’t been confirmed anywhere.

Although the likelihood of this hybridization occurring is pretty low, it is very likely that the two jackals endemic to Africa, the side-striped and black-backed jackals, can hybridize. The two species usually fight with each other, but there could be instances where they have crossed.

We just don’t have as many genetic studies on these jackals as we do with wolves, dogs, and coyotes.

But I bet there are some interesting stories in the genetic history of these canids.

They just have to be explored a bit more thoroughly.

Jackals are a mystery waiting to be solved.

 

 

 

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