Natural History

Red foxes are native to North America.

They were also introduced.

That sounds like a contradiction, but let me explain.

First, we should look at the North America red fox distribution map. Red foxes in North America have several subspecies.

Click to make larger.

Subspecies number 6 is Vulpes vulpes fulva.

It was traditionally believed that it didn’t exist until the seventeenth century, when English colonists introduced red foxes for hunting purposes.

I’ve often said that red foxes are not native to most of the Eastern United States and that they all derive from imports.

The trouble is that there have been few genetic studies on red foxes in the Eastern and Southern US that have made tried to figure out exactly where they came from.

Well, it turns out that this assertion may be wrong.  A recent mtDNA study revealed that North American red foxes, including those found in the Southeastern US, don’t have Eurasian red fox mtDNA haplotypes. That means that the matrilines of red foxes living in the Eastern US are derived from indigenous vixens, most likely those from Eastern Canada that colonized the United States in the middle of the nineteenth century.

Now, an mtDNA study cannot tell us everything about the genetic make-up of red foxes in North Ameriaca, and it is possible that some of their genetic material came from imported red foxes that were introduced in the seventeenth and eighteenth centuries.

A larger sample of red fox DNA is needed to see exactly what the ancestry of these foxes actually is.

However, this study is making me reconsider some of my assumptions about the local red fox population.

It’s true that red foxes weren’t here at the time of colonization. However, red fox remains that date to the time of time of the Wisconsin glaciation have been found in Virginia and Tennessee.  When glaciers retreated, the red fox moved north in Canada, where it remained until European colonization.

The traditional account states that red foxes in the Eastern and Southern US came from those imports, but there is a large gap between those introductions in the seventeenth and eighteenth centuries and the establishment of red foxes in this part of North America in the  middle of the nineteenth century.

It is possible that our foxes have a mixture of native and European blood.

But it is also possible that the imports never really became established, or if they became established, they became swamped with native red fox blood as they came pouring down from Canada. My guess is there never were that many imported red foxes. Foxes are wild dogs, and they would not have taken well to confinement on their way from England to North America. Further, foxes that evolved to live in a benign marine climate may not have been able to thrive in a place that has such extremes in heat and cold.

Compared to wolves and coyotes, we know next to nothing about how the different populations of red fox are related to each other. We’ve only recently been able to determine how coyotes colonized Virginia through the Great Lakes and Canada, and we’ve also been able to figure out that certain propose wolf species are actually derive from recent hybridization between coyotes and wolves.

These studies looked at a lot more genetic material than mtDNA haplotypes, and we’re going to need studies like these on red foxes to determine what their exact ancestry is.

But if our assumptions about red wolves can be challenged through extensive nuclear DNA studies, then our assumptions are likely to be challenged when we start looking at red foxes.

Maybe we should consider red foxes native to the Eastern US after all.

I think we need to see how much “native” ancestry they have before making that assertion.

But this mtDNA study is certainly a major affront to the tradition account of how red foxes colonized the Eastern United States.