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Archive for the ‘wild dogs’ Category

Jack bite

It’s a dog-eat-dog world out there. This came from a deer hunting page on Facebook.

Supervise your little dogs in coyote country, which is pretty much all of North America at this point.

coyote takes out jack russell

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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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qinling panda

Hundreds of species concepts exist, and within these concepts there are great controversies. As long time readers know, I am very skeptical of the validity of the red and Eastern wolves as distinct species, and I am even more controversial in that I think that the recent genome-wide analysis on coyotes and wolves have made question whether coyotes really should be thought of as a distinct species from wolves. I certainly don’t think it is controversial that wolves and dogs are the same species, but I’ve been drawn into long, drawn-out discussions about this subject.

If we accept these genome comparison studies (one that looked at wolves and domestic dogs and one that looked at wild North American wolves and coyotes), all North American Canis species, wild and domestic, have diverged from common ancestor within the past 50,000 years. There has been significant gene flow between wolves and coyotes across North America, including Alaska and Yellowstone National Park, where the wolves are said never to breed with coyotes,  and there is even more significant gene flow between wolves and domestic dogs in Eurasia.

These animals do not fit Ernst Mayr’s concept of species at all in which reproductive isolation is the most important feature. A species is a population of organisms that can reproduce and bring about fertile offspring.  Wolves, dogs, and coyotes can do these things.

Mayr’s concept has been criticized quite a bit because there are things that do reproduce and produce fertile offspring, but it doesn’t happen very much. Further, these two species could have been distinct for a very long time, such as the Grevy’s and plains zebra, which split about a million years ago but still are capable of producing fertile offspring.

Further, we’ve since gone into a different way of classifying animals in which descent from common ancestry is more important than arbitrary lines based upon more subjective features. This newer way of classifying organisms is called cladistics, and it fits with a way of organizing life that is deeply appreciative of evolution.

I prefer this way, but it certainly leads to controversy. If I say that dogs are wolves, am I endorsing an entire ways of viewing them that aren’t science-based at all. The arguments for strict dominance training models are based upon poorly designed studies of wolves, and the arguments for feeding dogs raw meat and bones are also based upon an appeal to nature argument that dogs are wolves.

But I am not making those arguments at all. I am simply placing dogs within the proper clade to which they belong in the wild bush that we once called the tree of life. I think, more controversially, that coyotes should be given the same proper placement.

My arguments for this classification have to do with the fact that gene flow still exists among all three populations and their very recent common ancestry.

This classification has to be put into perspective. For example, Old World and North American red foxes split from a common ancestor some 400,000 years ago.  A very good case can be made that red foxes are actually two species, just based upon that genome-wide analysis alone. There has been virtually no gene flow at all between the two red fox clades, except in Alaska, where some Old World foxes introgressed into the New World population there some 50,000 years ago.

There are also other species of large carnivora that ought to be recognized if we were paying a little more attention. The leopard of Java, commonly thought of as a insular dwarf of the common or spotted leopard, may have diverged from the rest of their species some 800,000 years ago. More recent estimates suggest that they split off about 600,000 years ago,

This leopard is not commonly thought of as a distinct species, but it is likely multitudes more distinct than wolves, coyotes, and dogs ever could be from each other. More study does need to be performed, of course, but it seems likely that the Javan leopard really is its own thing.

Perhaps the most compelling case for a hidden species in a large carnivoran that I’ve seen is the case of the Qinling panda. Currently, two subspecies of giant panda have been recognized in China. The more common type is black and white. It is the one commonly on loan to zoos in the West, and they are the pandas I saw as a boy at the Cincinnati Zoo.

But there is also a rarer form that is found only the Quinling mountains. It was always thought of as odd because it is brown and white, rather than black and white.  Because it is such an isolated population it was long suggested that its brown and white coloration was the result of inbreeding, and that may still be the case.

In 2005, this brown and white panda was given its own subspecies, usually just called the Qinling panda.

Full genome comparison of both forms of panda have revealed that they are quite distinct from each other. The two forms split 300,000 years ago,

Full genome comparisons revealed that coyotes and wolves split only 50,000 years ago. The same analysis revealed a much, much deeper division in giant pandas. Genomes revealed that there is a panda that really should be its own species. Call it the Qinling panda or the brown panda.

But moving this animal to a full species would mean that we have a very endangered species. There are no more than 300 Qinling pandas in the world, and it could be quite difficult to protect them.

The coyote and red and Eastern wolf problems revealed in genome comparisons are also quite complex. The coyote is in no way endangered. It has vastly expanded its range since European settlement– pretty much all of North America but the High Arctic has coyotes now.  The red and Eastern wolves have genes from now defunct wolf populations. Both of these wolves will continue to cross with coyotes, and the only way to keep them from becoming totally swamped with coyote blood is to keep coyotes out of their ranges, a nearly impossible task.

Meanwhile, Eastern coyotes with wolf ancestry are evolving larger bodies. They are refining pack-hunting behavior.  They are evolving into a sort of larger, pack-hunting wolf on their own.

What this means for wolf taxonomy and wolf conservation is really a complex question, but I don’t think this question can be answered until we fully account for the problems caused by both the recent split of wolves from coyote and the continued gene flow between them.

It is a question that really cannot be answered unless we’re looking at the broader picture.  They are nearly as distinct from each other as many other animals that we are conventionally classifying as a single species now.

 

 

 

 

 

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loose skinned arctic fox

The animal above is a super-sized blue phase arctic fox that is of a type being bred in Finland. The exposed haw is actually the result of being bred for super loose skin, a trait that those in the dog welfare community know very well. “Typy” shar pei and Neapolitan mastiffs are well-known sufferers from loose skin problems, but even a in breed that isn’t as exaggerated, like Clumber spaniels, this loose skin can lead to all sorts of eye infections.

This is a full-body shot of the Neapolitan arctic fox:

wrinkled fox

Why are arctic foxes being bred with such loose skin?

Well, that loose skin actually makes for a larger pelt and a larger pelt goes for higher price.  In nature, arctic foxes are quite small, much smaller than Boreal red fox subspecies, but the arctic fox in its winter fur is a much more valuable animal.

Both red and arctic foxes breed well in captivity, and they have been farmed extensively for their pelts. Captive red foxes come in many colors now, but the naturally-occurring silver phase was once the staple of fox pelt market. The arctic fox, especially its blue phase, is also quite valuable, but the smaller pelts mean they cannot compete with the silver phase reds.

These Finnish breeders have begun to produce large blue arctic foxes, some of which weigh 20 kg, and have very loose skin in order to make a much more profitable strain of arctic fox.

This development has several moral and ethical questions, as well as being something that those of us curious about dog domestication and evolution might find intriguing.

I should note that I am not anti-fur. I come from a long line of fur trappers, including my own paternal grandfather who used to trap red foxes to fund his union activities. He knew more about red foxes than anyone I’ve ever personally known, and he had a great appreciation for the species.

For some, the fact that these animals are being bred for fur is going to be the biggest ethical problem, but for me, it is the exaggeration in conformation that causes me greater worry.  When these animals are killed for their fur, it is done humanely. Finland is a leader in the humane treatment of animals, and killing fur-bearers on farms in a cruel fashion would not be allowed.  The standard practice is for the animal to be rendered unconscious, then electrocuted. (I don’t want to get into a long, drawn-out debate about these, because there are places where this practice isn’t followed. Finland isn’t one of them. )

But these foxes spent their entire lives with loose eyelids and a bulky conformation that puts an exorbitant amount of stress on their joints, and this truly is a welfare issue.

I see this as the main welfare issue of domestic dogs in the West. We’ve bred domestic dogs with such exaggerated conformation that we’re ultimately harming them, and the funny thing is these animal welfare sites that post shocking animal cruelty videos and images also generate web traffic with videos of cute little bulldogs and pugs with such shortened muzzles that they cannot breathe or cool themselves properly.

I find these loose-skinned arctic foxes appalling, in every way I find an extreme shar pei appalling.

And here I can agree with the animal rights activist. This is wrong.

But at the same time, my curious, scientific mind is intrigued. Fur farmed foxes are sort of parallel dog domestications.  Much has been written about the Belyaev fur farm experiments and what they might say about how dogs were domesticated, but the truth is virtually every fur farm breeding program for the various red and arctic fox phases is an experiment that could reveal some secrets about dog domestication.

It is amazing that we can selectively breed arctic foxes to reach the size of coyotes, and it is even more amazing that we can select for the loose skin in arctic foxes that we actively breed for in certain purebred dogs.

It would be interesting to get full-genome comparisons on these “monster foxes” and more typical arctic foxes.  Maybe the genetics are similar between these foxes and the super-sized and loose skinned domestic dog breeds we have produced.

If we are going to breed animals for agricultural purposes, we are going to have to do it humanely. I am certain the Finnish breeders of these foxes believe they have done a great agricultural improvement in much the same way their intellectual forebears in England in the eighteenth and early nineteenth centuries bred massive swine and beef cattle that could barely walk on their own hooves.

So yes, we have an ethical issue with these foxes, just as we have an ethical issue with the continued breeding of dogs with exessive loose skin and exposed haws.

 

 

 

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A Yellowstone wolf sounding hauntingly familiar:

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The cute little red fox is quite a savage beast. It also shows us that the current fad for filming rare or relatively rare birds on nests with the use of web cameras can sometimes wind up with the ending we weren’t expecting:

 

 

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The war of mesopredators and a family saga, sort of like wolves vs. grizzlies on a smaller scale:

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