Natural History

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.