Natural History

There is a famous book on the red fox entitled Red Fox: The Catlike Canine by J. David Henry (1986).

Never mind that foxes are not canines.  “Canine” refers to the dogs in the tribe Canini, which includes all the dogs in the genus Canis and its allies, Cuon and Lycaon, and all the South American wild dogs. True foxes belong to the other tribe within extant canids– the tribe Vulpini.  Red foxes, like all members of the dog family, are canids, but they are not canines. They are vulpines.

One of the main theses of the book is that red foxes are like cats. They have pupils that can contract to a vertical slit, a trait they share with cats– and all other vulpine foxes!  This adaptation allow them to adjust the amount of light exposure to their lenses, allowing them to see at varying levels of light. It is definitely a good adaptation for hunting at night.

Red foxes also eat a lot of mice.

So that makes them the true cat-like dog?

Well, there is another wild dog that lives in many of the same areas as the red fox that is far better candidate for this title than any vulpine.

I am, of course, referring to the so-called gray fox (Urocyon cinereoargenteus). Although it has classically been referred to as a vulpine, the most in-depth genomic study on the dog family showed it to be nothing of the sort. It is actually a very primitive wild dog species whose line branched off from the rest of the canids 10 million years ago. This is the oldest extant lineage within the entire dog family, and it should be regarded as neither canine or vulpine. It is a basal canid that should be regarded as existing as part of its own tribe.  The only good reason to call it a fox is because it superficially looks like one.

As a primitive canid, it retains some features that it shares with only the raccoon dog (Nyctereutes procyonoides). The raccoon dog is a native of Northeast Asia, and it has also traditionally been considered a basal canid. However, the same genomic study that found the  gray fox to be a very ancient lineage also found that the racoon dog is actually a basal vulpine, as is the bat-eared fox, which has also been traditionally regarded as a basal canid. If we are to accept this new taxonomic position, then the raccoon dog, on average, would be the largest vulpine, not the red fox.

The most important traits that the gray fox shares with the raccoon dog are its specialized adaptations for climbing. Both of these species still retain the hooked claws that make trees more readily accessible, and both are relatively short-legged, which allows the body to hug branches and trunks more closely as it climbs. However, the gray fox is by far the more arboreal of the two, and it can access trees with all the agility of a domestic cat.

And because it can climb trees, it is actually much more ecologically like a domestic cat than the red fox or any other vulpine is.  If one can readily climb trees, then one can readily raid bird nests. Most of the United States never had small cats. The smallest species of cat that was widespread in the US was the bobcat, and in many areas, bobcats tend to attack larger prey than any domestic cat would.

No one really has examined how many birds gray foxes eat every year, but it is surely not to be a small number.

Of course gray foxes actually have their paws in several different niches.  They hunt rabbits and rodents in much the same way that red foxes do, and in part of the Eastern US, they are thought be a more significant predator of the various species of cottontail than red foxes are.   And gray foxes are quite omnivorous, often eating fruit and vegetable matter in much the same way we’d expect from a raccoon.

Gray foxes are really cat-like in their  movements.

The first one I ever got a good look at was running straight towards me as it pursued a cottontail rabbit that the passage of my feet next to a tangle of multiflora rose happened to flush out. The rabbit bolted uphill toward the place where the fox was waiting, and then upon seeing the fox, charged for the undergrowth to my left.  The fox took off after the rabbit and came running toward me. Because of its color and because it was running so fluidly, I thought I was actually looking at a cougar.

It made me stop.  Let’s just say that!

Miley was just a small puppy at the time and was running along beside me And she stopped, too. Old Strawberry, the 14-year-old golden, was plodding along behind me, and she stopped right when I did.

The fox suddenly slammed on the brakes, and it looked me over. It didn’t expect to see me coming along, but as soon as it realized what I was, it made two or three hard galloping leaps for the cover.

And it was gone.

But I can never forget those two or three seconds that it stopped short and stared up at me.

Anyone who has been around dogs for very long can read a gray fox, even if 10 million years of evolution separate them from domestic dogs.

I could see the expression on its face switch from the intensity of a predatory dog locked onto its prey to  that of absolute terror when it finally realized that its desire for a rabbit dinner suddenly nearly delivered before its worst enemy– a human with a pair of dogs in tow.

Gray foxes fascinate me to no end.

Theirs is an ancient lineage. This land was theirs before the first red foxes wandered down out toward the end of the last glacial maximum– and even after that, the red fox would largely be a stranger to these woods until at least the eighteenth century, when British colonists imported large number of English foxes to augment their numbers for fox hunting purposes. These particular woods probably never had a healthy population of red foxes until  the 1830’s.

We like to think of foxes red and gray, but I think this is not the best way to consider them.

There are red foxes.

And then there is Urocyon.

The little cougar dog of the undergrowth– and sometimes of the canopy!