Wild Ideas: Signs that the spring baby boom has begun

The first day of spring (March 20) was marked not only by Winter Storm Toby dumping some ice and snow on our area but also by signs that foxes are busy with new pups. One of the best things about spring is the baby boom that occurs this time of the year for many wildlife species.

As I was looking across a pasture on a hill above Sperryville, I saw a red fox (Vulpes vulpes) carrying a large cottontail in its jaws. If the fox had planned to eat the rabbit, it likely would have done so immediately after killing it, and the rabbit looked intact.

Seeing that the fox was headed for a steep, rocky and wooded hillside that is a favorite denning area for red foxes, I figured it was taking its prize back to its den for its family. Later in the spring, I’ve often enjoyed seeing older fox pups at play in the area.

The fox came back across the field a couple of minutes later, adding further evidence to my theory. In Virginia, red fox pups are usually born in March or April, so probably would not be ready for solid food by the time I saw the fox lugging the rabbit. The more likely scenario was that this was a male bringing food to his mate, who needed to stay in the den to feed and otherwise take care of their young pups.

Red fox ox pups are born with fine, gray-brown fur. By Siga via Wikimedia

In refreshing my memory on fox reproduction, I checked online with the U.S. Fish and Wildlife Service (USFWS) website and the Virginia Fish and Wildlife Information Service (VFWIS) website, which supplied most of the data below.

The female red fox usually has only one litter a year, breeding in the winter, and her mate sticks around to help rear the young. The species’ gestation period is 51–53 days, with litter sizes ranging from four to 17, averaging about five in Virginia.

While red foxes prefer taking over woodchuck burrows with two or more entrances as dens, they will sometimes dig their own. One study showed that these dens were, on average, 2-4 feet deep and 10-14 feet in total length. Although red foxes can form groups with more than one female, especially when denning, in much of North America, social groups are just pairs, according to USFWS.

Red fox pups weigh 2.4–4 ounces at birth and have fine, gray-brown fur. The color changes as they mature, usually becoming a reddish-brown by 14 weeks, often with gray along their flanks, like the one I saw that day, or with black guard hairs that make the coat look darker. Some mature red foxes are silver and dark gray to black, a natural color morph of the species; a red fox with this coloring is often called a “silver fox.” Red foxes often also have white on their throats, which may extend up to the lower jaw and back of the neck, and a white-tipped tail.

As they age, most red fox pups turn reddish-brown, although the species also has darker color morphs. By U.S. Fish and Wildlife Service

The pups open their eyes in nine days and start walking in three weeks. Once the female can safely leave the pups alone in the den for short periods, both parents hunt. By around five weeks, pups appear at the den entrance and are weaned in eight to 10 weeks. Juvenile males are typically larger than juvenile females, and both reach their full size in about 6 months.

Adult red foxes usually have a combination of reddish-brown and gray fur, often with white on the throat and chest, and on the tip of the tail. By U.S. Fish and Wildlife Service

The parents often move their young to at least one alternate den before the pups are six weeks old, with litters sometimes split — half residing in one den and half in another. At around 12 weeks, the young foxes start exploring their parents’ home range. They disperse from late August to October, with the males going first and farther than the females. Most red foxes in the wild live three or four years.

Like many other canids, red foxes are opportunistic when it comes to their diet. Although their principal prey are rabbits and rodents, their diet also includes woodchucks, birds, eggs and large insects (especially beetles and grubs), the occasional small domestic cat or dog, other small prey, plants and fruit.

Rabbits and small rodents make up most of the red fox’s diet, but it is an opportunistic feeder, eating a wide variety of other foods. By U.S. Fish and Wildlife Service

When I lived on a large farm in Huntly years ago, I used to sit and watch the den of a fox family that was on a hill in a field near my house. The young were as much fun to watch at play as any dog pups. They seemed to tolerate the dog I had at the time, a Belgian Tervuren named Mai Coh, who could get close to the den when the pups were out. They were more skittish about my presence, so I stayed far enough away not to disturb them.

Often called “silver foxes,” these red foxes display a naturally occurring color morph in their species. By Zefram via Wikimedia

While neither Mai Coh nor I did posed a threat, but other dogs might, including my current dog, who enthusiastically chases foxes up the mountain where we live. Fortunately, the adult foxes are fast, smart, and have lots of cover up there, so they easily escape her.

© 2018 Pam Owen

Pam Owen
About Pam Owen 341 Articles
Writer, editor, photographer, and passionate nature conservationist living in Rappahannock County, in the Blue Ridge Mountains of Virginia. Two favorite quotes: By E.O. Wilson, who coined the term "biodiversity," "Nature holds the key to our aesthetic, intellectual, cognitive and even spiritual satisfaction”; by Douglas Adams, “I love deadlines. I love the whooshing sound they make as they pass by.”