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Posts Tagged ‘hybrid fox’

bassingbourn black fox

The animal above was an anomalous black fox that was photographed near the village of Bassingbourn in South Cambridgeshire.  The photographer, John Moore, spotted the fox running in the fields near his home and snapped some photos.  It was late March in 2012, and it was a true rare find.

Foxes that are any color other than the typical red are extremely uncommon in the UK, so when these photos were published, speculation about where it came from were rampant. One theory was that it was one of the Belyaev “domesticated” foxes, which were then being sold as pets. Another suggestion was that it was a fur farm escapee. The problem with that theory is that fur farms had been banned in England and Wales since the year 2000, and those last remaining fur farms were mink producers, not fox producers.

Just a few days after John Moore took the photos, the black fox was found dead on the highway. Its body was sent to Anglia Ruskin University for genetic testing to determine why this particular fox was black.

Genetic testing revealed something quite unusual about it.  The vixen was found to have two genetic mutations related to fur color that were similar to those found in raccoon dogs.

Raccoon dogs are very closely related to foxes, and in Russia, they are commonly bred in fur farms that also contain (silver) red foxes and (blue) arctic foxes. Because of the similarity between this fox’s fur color genes and those of a raccoon dog, it was given as evidence that this animal was a Belyaev fox that had been turned loose.

It would make some sense. After all, this vixen was estimated to have been 18 months old, and she was apparently so unwise around roads that she soon met her demise on the highway. Further, her coat was much thicker than a typical English red fox. Maybe someone with more money than sense had ordered up one of these famed “domesticated” foxes, and soon realized they aren’t that awesome to have as pets.

And the poor thing got turned loose to live with the wild English foxes, which is about as a humane thing to do as turning out a cocker spaniel into Alaska to go live with the wolves.

So this logic is easy enough to follow.

The issue that seems to be ignored in all of the discussion about what this fox was is whether it is actually possible for a raccoon dog to hybridize with a red fox.

Ignore what you’ve read in various texts about raccoon dogs. They are actually quite close related to the true foxes. Genome-wide analyses have revealed that they are close enough to the other Vulpini to be classified with them.

They are quite unusual as wild dogs go. They can “hibernate,” which means they just sort of go to sleep during the worst of the winter (but it’s not really “true hibernation.”) They also have masks, and rather superficially resemble actual raccoons. It was not unusual for taxonomists to classify them as a sort of Old World raccoon species. We now know they are actual dogs, but the idea of them being sort of dog-like procyonids certainly captured more than a few imaginations.

So the notion that these animals could hybridize with red foxes would seem far-fetched.

But maybe they have.

The Soviet Union was really interested in fur. Historically, Russia has been a nation of fur-wearers. Furs drove them east and north into new territories, and when fur farms became a possibility, improving fur stains became an important goal. This goal went on in earnest during the Stalin years, and Belyaev, a Mendelian, was driven from his initial research post to accommodate Lysenkoist methodologies. He went to a research facility in Novosibirsk,  where he conducted his experiments on silver foxes.

The Soviet ideology believed that nature could be bent to serve mankind. Socialism in one country meant quite a bit of scarcity, even in the largest country in the world, and it was hoped that the new Soviet science could use native flora and fauna to produce abundance. This abundance would soon provision their citizens, and the Marxist ideal of “from each according to his ability, to each according to his needs” would be possible. Then this ideal would spread to other countries of the world, leading us to a new socialist future and then full-on communism.

It never really worked out, and we all know of the ecological catastrophes that happened as a result of these plans, including the introduction of raccoon dogs to Eastern Europe.

But they made some sense with in the logic of that system.

And if some enterprising Soviet fur farmer wanted to try something different, he might try crossing his silver foxes with raccoon dogs. Maybe he did in the years following the war, when scarcity was the rule, and getting new blood for foxes and raccoon dogs would have been an ordeal.

But this still doesn’t answer the question.

The fact that someone might try crossing the two species is interesting enough, but the question is whether one can produce viable offspring. And the next question whether any of the offspring would be fertile.

I have yet to find the answer to those questions, except that I am aware that red and arctic fox hybrids are sterile.

And those two species are much more closely related to each other than raccoon dogs are to red foxes.

So maybe the black fox of Bassingbourn really wasn’t a hybrid or of distant hybrid ancestry. The similarities in her genotype could have simply been the result of the fact that both red foxes and raccoon dogs share a common ancestor. This fox simply retained a few genes that she held in common with the raccoon dog.

I think that this is a bit better explanation, but the British press took the suggestion that she might have been a hybrid a bit too far. Virtually every mention of this fox online or in print says that she was a hybrid.

I wish, though, that more research had been performed this fox. If she really were the result of a hybridization on a Russian fur farm, it would be possible to detect this hybridization with more analysis of her genome.

The fact that she had just been killed when her body was donated to science meant that lots of different tests could have been performed.

If she really had been derived from hybridization between these two species, this would have been a major discovery.

I don’t think anyone would have expected it.

But Occam’s razor tells me that she wasn’t derived from hybrids.

As much as I’d like her to be, my educated guess is she wasn’t.

And the British press had a lot of fun with it.

 

 

 

 

 

 

 

 

 

 

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The most common phase for captive red foxes in captivity is the silver variety, and the most common phase for the arctic fox is the blue phase. Thus, most hybrids are silvery blue in color.

My guess is this is hybrid is the same phase combo, just in winter pelt.

However, the red fox in this hybrid was likely a cross fox-because it looks like a very freaky cross fox!

It could even almost pass for a swift fox, which is a very close relative of the arctic fox– a much closer relative to it than the red fox is.

Perhaps they could produce fertile offspring, for it is well established that a fertile hybrid zone existswhere kit foxes and swift foxes share territory in New Mexico. At one time, they were regarded as belonging to the same species, but it has since been determined that swift foxes and kit foxes are as genetically divergent as swift foxes are from arctic foxes. That means that the swift fox could produce fertile offspring with an arctic fox– but I doubt that anyone would try to do this breeding experiment.

I should note that because of their relationship to red foxes and swift and kit foxes, the arctic fox is no longer in its own genus. It is now in the genus Vulpes, with the vast majority of the other true foxes.

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