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Posts Tagged ‘Texas blue dogs’

It never ceases to amaze me about how poorly informed people are about the natural world.

Whenever someone runs into a wild animal that is hairless for some reason, the imagination starts running wild.  People start making claims that they’ve seen some sort of new species, perhaps an extraterrestrial or something from a secret government lab.

You often run into internet experts who swear that an animal can’t be merely a common animal with alopecia– “because it looks so different!”

Never mind that genetic studies clearly reveal the animal’s identity.  It must be something unique!

Most northern hemisphere mammals are pretty well-furred.

From a distance, we don’t normally see the animal’s musculature or physique. We don’t see how its ears fit into the skull.  We don’t see how the head is really shaped.  The fur hides that much.

When the fur is gone, all of these features are revealed, and they do make the animal look more bizarre.

My personal favorite of all these amazing new animals is the chupacabra.

Pretty much every chupacabra ever killed or described to science has turned out to be either a dog or a coyote.  In Puerto Rico, some might even be mongooses, which were introduced to control the rat population. On the  US mainland, some chupacabras have turned out to be raccoons.

But the vast majority of these chupacabras have turned out to be canids. Some have been red foxes, but they most usually have been coyotes or domestic dogs.

And when the animal’s skin can be tested for disease, it almost always turns out that Sarcoptes scabei is the culprit.  In short, these animals are hairless because of a severe case of sarcoptic mange.

The dead canid in the photo above is one two similarly afflicted individuals that were found in the vicinity of Cuero, Texas.

It was the second one to have its DNA analyzed. The first was found dead on a ranch in the vicinity of the town. DNA tests revealed that it was a coyote.

The second one was shot in roughly the same area, and it turned out to be a bit different. It had coyote mtDNA, but its y-chromosome was that of a Mexican wolf (Canis lupus baileyi).  Y-chromosome tests merely trace paternal heritage, so it is very possible somewhere along the way, a Mexican wolf mated with a coyote somewhere in that region. The offspring then bred back into coyotes, and through each generation, the wolf component of their ancestry became diluted.  But the Mexican wolf y-chromosome remained, even though these animals are coyotes.

Now, that finding is much, much more interesting than all the crap that has been written about these particular chupacabras from Cuero. The woman who collected these samples runs a website that is full of denialism about what these animals actually are. I am particularly enjoying her claim that the tracks of these animals don’t look like those of coyotes, even though the track pictured looks exactly like the coyote track I photographed two years ago.

To me, it’s a much more amazing find to discover that Mexican wolves have contributed a few genes to the Texas coyote population.

It’s a much more amazing discovery than anything people can imagine about these animals being a unique species, which some have suggested should be called a “Texas blue dog.” (I thought that was a political term!)

This animal is yet another example of the wondrous species complex that exists between Canis lupus and Canis latrans.

Trying to turn these animals into unique species really isn’t that different from what people have tried to do with the red wolf and the so-called Eastern wolf species. Both have ancestry from both wolves and coyotes, but that does not make them unique species at all.

If the case for the Eastern wolf and red wolf as distinct species is that terrible, the case for the Texas blue dog is even worse off.  Its blue eye and so-called “pouches” aren’t going to make any difference.

Coyotes can have blue eyes.

This one, I believe, was killed in New Mexico, where the coyotes are either free or almost entirely free of dog ancestry:

They actually can get bluer than this one. Coyotes may have a mutation that causes blue eyes that is entirely different from what causes blue eyes in domestic dogs. No one has performed any analysis to determine why coyotes, even those from populations that have not been known to cross with dogs, like the ones in the Southwest, sometimes have blue eyes.

As for the pouches, those are actually cysts called hygromas that develop when an animal spends so much time sitting on its haunches scratching its neck.  Which is exactly what we’d expect from an animal suffering from a severe case of sarcoptic mange.

Of course, Texas isn’t a place where knowledge about zoology should be expected. This is, after all, the state that attempted to  introduce creationist textbooks into the class room.

I’m not saying everyone in Texas is an idiot, but any state that would elect this guy governor has a large number of citizens who have issues with critical thinking.

The discovery of a coyote with a Mexican wolf y-chromosome is an amazing discovery. If we’ve found one coyote with this ancestry, there are likely many of them.

There are lots of questions to ask about these coyotes.  When did the y-chromosome enter the population? How widespread are coyotes with this ancestry?  These questions are very much worth asking.

After all, the Mexican wolf is the most critically endangered subspecies of wolf in North America, and although its former range included Texas, the exact limits of its historical range are not clear. There is some evidence that it occurred as far north as Colorado, and its range in Texas may have been more extensive than we currently estimate.

But we can’t ask that question when we’re trying to turn these animals into paranormal bloodsuckers.

I know that chupacabras get the headlines.

But we’ve actually found something quite interesting here.

The truth is actually much more amazing than anything our imaginations could contrive.

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Listen to the whole interview.

I regularly comment on the CFZ’s blog. I’m most often a skeptic. In fact, it’s hard to get me entirely sold on a theory in cryptozoology.

And I’m more than a little bit skeptical about some of this.

Some points:

1. The only dogs that climb trees are gray foxes (which live in North, Central, and South America. They are found in Texas) and raccoon dogs, which are entirely out of the picture.

2. Mexican wolves are not the most primitive subspecies of wolf.  We actually don’t know which one it is, but it is usually suggested that the red wolf or the Indian wolf is. (I’m reviewing something that talks about this issue, but I’m not at liberty to discuss it right now.) Those two animals are sometimes called a separate species, but if one considers them to be the same species as the rest, then they become the most primitive. They look very similar to each other for a reason!

3. It is very possible that a coyote might have Mexican wolf DNA.  This doesn not surprise me at all. In West Virginia, coyotes have been found with domestic dog mtDNA. The red wolf commonly has something like coyote mtDNA, although at least one specimen had wolf mtDNA. These critters exchange genes. It’s only now that we’re starting to look at it. For example, black wolves got their coloration from crossbreeding with black domestic dogs. Maybe those hairless dogs from Mexico have exchanged genes with the coyotes in Texas. Or maybe the coyotes are developing a hairless adaptation to live at high densities in Texas. This one reason why Latin American dogs developed the hairless trait. It was a defense against ectoparasites.

4. I don’t think some sort of skin disease can be ruled out. I’m not sure of which one.

5. It sounds like several species are involved. Gray foxes in subtropical and tropical populations often shed out and look like this or like this. Gray foxes could also explain the tree climbing behavior.

I’ve always found this stuff interesting, and I’ve always found the people who do this professionally even more so.

But I’m skeptical.

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It has nothing to do with politics.

It is also not the blue lacy dog (“state dog of Texas.”)

It’s this thing:

Source.

“It looks like a coyote.”

“Tests say it was some sort of coyote.”

My guess is that these animals are coyotes with mange.

However, they could be coyotes that are evolving sparse hair– perhaps with an infusion of Latin American hairless dog genes.

It is speculated that sparse hair and hairlessness evolved in domestic dogs in Latin America as a way of dealing with ectoparasites.

In Pre-Columbian Latin America, larger numbers of dogs existed in very high densities. Dogs were food and sacrificial animals for some civilizations. It is also very likely that ectoparasites were a major problem. Having sparse hair or hairlessness is one way to deal with these parasites. The bugs are more easily plucked from the bare skin than they are from thick coats. If you’ve ever had a tick in your hair, you know how much harder it is to get it out than it is to pluck it off your leg.

Coyotes do exist at very high densities in parts of Texas, so it is possible that this same sort of environmental pressure is resulting the evolution of the same adaptation.

Of course, hairlessness in domestic dogs was always encouraged through selective breeding. If a dog didn’t have hair, it would be more likely to mate before it got eaten or sacrificed.

I think these animals will prove to be “some sort of coyote.”

That’s my guess.

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