Last week, while I was driving my daughter to school, the most widely distributed carnivore in the world dashed in front of the truck. Despite its wide distribution, a red fox is an animal I seldom see, so I slowed down and we watched as it disappeared into the brushy old field.
Red foxes occur in North America, Asia, Europe and northern Africa, and in about 1850 they were introduced to Australia where they also now roam widely. European settlers also introduced them to North America around 1790. It's likely they occurred naturally here, but the dense eastern forests provided less than ideal habitat. Red foxes prefer forest edges, meadows, pastures, old fields and crop land.
Gray foxes were the common canine of the eastern deciduous forest.
Waxed and waned
Over the last 200 years the fortunes of the red fox have waxed and waned. As Europeans settled across North America, they managed to drive wolf populations to the brink of extinction. This, combined with extensive changes in the landscape from forest to farmland, allowed red foxes to flourish.
More recent, however, red foxes have not fared so well. Thanks to the range expansion of coyotes, which are becoming increasingly common throughout the east, red fox numbers have declined. Coyotes view red foxes as both competitor and prey. Where their ranges overlap, coyotes usually eliminate them. This may explain why I consider seeing a red fox noteworthy.
Despite the deleterious influence of coyotes, an understanding the natural history of red foxes explains their global success.
Their luxurious fur coat provides ample insulation against the cold of even the northern reaches of Alaska and Canada. I can't imagine a toastier mammal on a cold winter day than a red fox curled up with its nose buried in the thick blanket of its own tail.
With their preference for open habitats, red foxes seemed predestined to thrive as settlers opened up the wilderness. Their diet is equally broad and opportunistic. Favorite foods include mice, rabbits and hares. But they eat just about anything, including other small mammals, carrion, birds (especially eggs and chicks of ground nesting species), snakes, turtles, frogs, insects, earthworms and fruits. When you can live almost anywhere and eat almost anything, the odds of success are good. Many other common species live by similar rules raccoons, opossums, skunks, deer mice, crows, box turtles, and toads come immediately to mind.
The hunting behavior of the red fox can be surprisingly catlike, hence the subtitle of a 1986 Smithsonian book by J.D. Henry, "Red Fox: The Catlike Canine."
To catch rodents in open fields, a red fox locates a victim, then springs cat-like into the air toward and above it. It can accurately pounce on a mouse from as far as 15 feet away.
The distinctive red coat and white-tipped tail make red foxes easy to recognize. They are, however, much smaller than they appear. They measure only 32 to 43 inches in length (a third of which is tail), and they weigh six to 15 pounds. Their thick fur coat often makes them appear a good bit larger.
Their gestational cycle
Female foxes, called vixens, come into heat for just a few days sometime in late winter, so watch for red foxes on the move. Females give birth to an average of five pups about 52 days after mating. The den may be dug by the parents or it may be a remodeled groundhog den. The main entrance is usually about 10 inches in diameter, and often there are several exits. At birth, pups weigh about three ounces and even then have the white-tipped tail. Pups nurse for up to 70 days, during which time the male provides food for the family.
At about five weeks of age the kits leave the den and play near its entrance. If ever you get to watch a litter of foxes fighting and frolicking outside a den, treasure it. Each spring I hear from a few lucky readers who report such encounters with the catlike canine.