Although the red phase is most common, Red Foxes exhibit many color variations. Among the non-red phases, you might find the cross phase, with a dark area across the shoulders and down middle of back—in the shape of an eponymous cross—and the identifying white tail tip; and the black phase (also referred to as a silver fox), with black fur tipped with white and (of course) that white tip on tail. Intermediate phases of all sorts can also occur. So don’t be fooled by an unusual color. If you see a white tail tip on a dog-like wild animal, you’re looking at a Red Fox.
Foxes don’t spend much time in and around dens, except during breeding season. Even in the winter, they sleep in the open with their bushy tails curled around their noses and feet for warmth. (Here’s a photo of this pose—how cozy does that fox look?) During breeding season, they usually have at least one spare den so the kits can be moved on short notice if the original den is disturbed. DNA studies of kits have shown that Red Foxes are primarily monogamous during breeding season but not completely so.
The scientific name for Red Fox has shifted through the years. In the 1600s, Red Foxes (species name Vulpes vulpes)were brought to North America from Europe for hunting. As so often happens with imported species, some of these foxes escaped or were deliberately released. Some reports say that these escaped foxes began mating with the native Gray Fox. However, since the Gray Fox is a different genus and species—and such different species typically don’t produce fertile offspring, if they mate at all—this may or may not be true. The North American Red Foxes became known first as Vulpes fulva, in contrast to the European Vulpes vulpes. Lately, though, the name Vulpes fulva has fallen out of use (perhaps in response to the possibility that Red Foxes and Gray Foxes may have never interbred successfully). Instead, both Red Foxes are now classified as Vulpes vulpes. The distinction is noted through the subspecies names: V. v. vulpes (the European Red Fox) and the V.v. fulva (the North American Red Fox). For the curious, “vulpes” is Latin for “fox;” “fulva,” for “tawny” or “yellowish brown.” So we have, in effect, “fox fox fox” and “fox fox tawny.” Yet again, scientific names from the Department of Redundancy Department.