Natural History

Many people don’t like that I consider dogs to be the same species as wolves.

And usually what they’ll do is accuse me of holding views I don’t have.

For example, I don’t say that the average person should keep a pet wolf. The chances of that going wrong are just too high, but it doesn’t mean that it will never work out.  I have to point to several cases of people keeping wolves and having no problems with them, most notably Wags, the tame wolf that Adolph Murie kept while studying the wolves of Denali. Wags was taken from the den of a wild pack, and she wound up becoming something like a golden retriever in wolf form. Wolves have also been trained as hunting dogs and working dogs, and at least one turned out to be a decent bird dog and retriever.

However, the chances of a human-wolf relationship going wrong are very high, so I do not recommend that people keep pet wolves without learning as a much as they can– and of course, getting the proper licenses.

The other attack I get is that I think dogs are wolves, and therefore, I must believe that we should use compulsory, alpha-based training regimes.

That’s a position I not only don’t have, it is a position I have denounced as utterly unscientific and untenable in the modern era. (See Mark Derr’s piece in the New York Times for a good explanation of why).

Now those first two are pretty easily dealt with, but a third one requires a bit more of an explanation.

This third argument requires a bit sophistication to fully understand, but it’s one that I think can be explained if we look at other cases in nature for comparison.

This argument is one that is made by Raymond Coppinger in his book on dog domestication and behavior. There is a chapter in the book in which he denounces any attempt to represent dog phylogeny in their scientific name, which is Canis lupus familiaris. Coppinger totally defends the old scientific name Canis familiaris because dogs and wolves occupy different ecological nichees.

It’s definitely true that lap dogs have a very different ecological niche than large moose- and bison-hunting wolves in Canada.

However, what about Middle Eastern pariah dogs and Arabian wolves?  Both animals scavenge for most of their food. Neither forms large packs based upon a mated pair, but they essentially  have the same ecological niche. And they do exchange genes quite a bit, although because the wolves are far less common, this gene exchange is much more limited than it might have been.

The same goes for the wolves and stray dogs of Italy. These dogs and wolves don’t hunt prey, because there aren’t many prey species about. Instead, they hang out at garbage dumps and live on that. The wolves of Italy are much more interbred with dogs than people realize. Dog genes for black coats and dewclaws on the hindlegs are working their way into the wolf population.

If we actually take Coppinger’s argument out to its logical end, then wolves themselves represent several species, even though genetically they comprise just a single species. Wolves in the high arctic hunt muskoxen, while wolves in the Middle East hunt gazelles and hares and mainly scavenge. The newly discovered African wolf subspecies (Canis lupus lupaster) isn’t even the top predator in its ecosystem, and it subsists largely by scavenging kills and hunting small prey.

Yet they are all classified as wolves (Canis lupus).

If wolves can occupy such a wide variety of ecological niches and still be considered the same species, why on earth would we not broaden it out and allow dogs to be classified as wolves?

Just as Arabian wolves are adapted to living in the deserts and arctic wolves have adapted to living in polar regions, domestic dogs are wolves that have adapted to live with humans.

I don’t know why this is so hard to accept, but there is a lot of resistance in some quarters to considering dogs a subspecies of wolf.

But that’s exactly what they are.

Now, in other species, there are different subspecies that have different ecological niches, but no one contends that they should be separated into distinct species on the basis of their differing niches.

Let me give you one that is pretty close to home.

To me, this is a fox squirrel (Sciurus niger).

Eastern or northern fox squirrel (Sciurus niger vulpinus).

It’s a big squirrel with thick tawny gold tail and belly.  They live on the border of pastures and hardwood forests, and they are more common along river valleys in West Virginia than ridgetops. Densely forested ridges tend to have mostly Eastern gray squirrels, which are smaller and usually have gray tails with white banding. In my area, these are the two most common squirrels, although one sometimes see American red squirrels (“fairydiddles.”)  The fox squirrel is the largest tree squirrel in North America, and it is from this subspecies that they get their common name. Their tales actually look like those of a red fox, and their full scientific name reflects this similarity– Sciurus niger vulpinus. This subspecies is found from the interior Mid-Atlantic states and the Appalachians north and west to the prairie provinces.

However, this is also a fox squirrel:

Southern fox squirrel (Sciurus niger niger).

This is the Southern fox squirrel, and it is the subspecies one will find in Eastern North Carolina and most of South Carolina.

They superficially look nothing like the fox squirrels I know so well, but they are considered the same species.

However, the two subspecies are quite different from each other.

The vulpinus subspecies is quite adaptable. They have been introduced to California, where they have thrived, and if you can live from Applachia to Saskatchewan, you can do pretty well no matter what the conditions are.

The niger subspecies is in decline. They are almost entirely dependent upon the long-leaf pine forests that once covered much of the Southeast. For those of you who have not been in this part of the South, most of the land is dominated by subtropical pine forests. Historically, the long-leaf pine has been the dominant pine, but these old growth long-leaf pine forests have been cut– and the land was replanted with more commercially lucrative short-leafed and loblolly pines.  The fox squirrels prefer the more open understories that the long-leaf pines provide, and the short-leaf and loblolly forests are much better suited for Eastern gray squirrels.

In states that have both vulpinus and niger fox squirels, the vulpinus subspecies prefers to live in any available oak-hickory forests, while the niger subspecies prefers to live where there are stands of subtropical pine– especially if it’s long-leaf.  In some parts of the Piedmont, these two different kinds of forest can be relatively close to each other, but as far as I know, no transitional zones between vulpinus and niger fox squirrels have been documented. They probably do exchange genes where their ranges overlap, but because niger fox squirrels are so habitat specific, there likely isn’t much of one.

No one consideres vulpinus fox squirrels a separate species from niger fox squirrels, even though they have very different ecological niches. The niger subspecies is also quite a bit larger than the vulpinus subspecies, which is in conflict with Bergmann’s rule. In other normal situations, taxonomists would at least try to consider them to be different species.

In fact, they have a better claim to having a separate species status than dogs and wolves, but I don’t think anyone would seriously consider these fox squirrels to be different species.

After all, there are several different subspecies of fox squirrel besides these two.  The most famous is the critically endangered Delmarva fox squirrel (Sciurus niger cinereus), which looks like a giant Eastern gray squirrel, which even more habitat specific than the Southern fox squirrel. They also are specialized to living in the Mid-Atlantic pine forests from Southern New Jersey to the Virginia’s Eastern Shore. It currently is found only in Eastern Shore portions of Virginia and Maryland.

Vulpinus fox squirrels are much more habitat generalists than either the Southern or Delmarva fox squirrels. They have a different ecological niche, and if one really wants to play around with Coppinger’s adamant defense of Canis familiaris, then we have to split up the fox squirrel species.

Ecological niche can be used to determine species status, but to rely upon it alone, as Coppinger does in his defense of the usage of Canis familiaris, is to inadvertently open up whole taxons to splits that are pretty hard to justify on face value.

So if one isn’t willing to say that there are multiple species of fox squirrel, we are going to have go with Canis lupus familiaris.

Sorry, folks. Dogs are wolves.  The arguments on the contrary make no sense in the light of what we know about other species.

Update: It turns out that all these subspecies of fox squirrel have only diverged in the past 14,000 years.