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The Fox

The fox is a member of the dog family, the canidae, but there are some differences: foxes can't be crossed with other canids (wolves, dogs, coyotes,...). Foxes are also the only canids that have elliptic upright pupils, like cats. There are different varieties of foxes, like the well-known fennec fox and polar fox, but also less known and even endangered species, like the kit fox and the Falklandfox, a species that is completely destroyed by the fur trade. There are 21 different species in all. Here we will discuss the most well-known and the most widespread species, namely the red fox (vulpes vulpes) or fox.

The fox is a predator and his indispensable role in nature is regulating little (mice) to medium-sized (hare) animals of prey. In the faun where the fox belongs to, there is a perfect balance between predators and animals of prey: on the one hand, the body and the senses of the fox are perfectly developed to hunt little to medium-sized animals of prey. But on the other hand, these animals of prey can stand up to foxes because they are found in large numbers (mice). Moreover, they can maintain that amount despite the presence of predators or because they are perfectly able to escape from an attack (f.e. rabbits are extremely nimble animals and because of this characteristic they can usually escape foxes). The fox has no natural ennemies (although human beings sometimes hunt the fox quite intensively they cannot be regarded as natural ennemies, because the hunting of foxes doesn't take place in a natural way). After all, the fox is a toppredator. There are even bigger predators than foxes, like wolves and bears, but to them the fox is just an accidental and negligible prey. In Belgium (and in a lot of other countries too) f.e., the number of foxes killed in traffic is higher than the number that would become prey to bigger predators, if these predators would be present to a normal extent.

Foxes are solitary hunters: the preys that they hunt are usually too small to be shared with other foxes and to make hunting in groups significant. Still foxes share their lives in a group. The basis of such a group is the dominant dog fox and one dominant vixen. Depending on different factors (food-supply, size of territory, hunting pressure,...) this couple is accompanied by several vixen. They usually come from previous holes. Dog foxes are chased away from the group once they have grown up. This is one of the things that determines the population density. Foxes live in a fixed community or territory. A fox doesn't like other foxes (except the group members) to intrude on its territory because it draws its food mainly from that territory. Depending on the food-supply in a territory, the size of this territory, the amount of individuals per territory and the number of births will increase or decrease proportionally.
In that way, the fox is perfectly able to regulate the amount of foxes without external help (=> predators and/or human interference) and without danger for other faun. This means that the amount of foxes is regulated by the amount of animals of prey and not the other way around!
A fox territory can vary from 1200 hectare in rough territory (high mountains) to 100 hectare in a human environment (suburbs, parks,...), 600 hectare is the most common size. Foxes are found in the most divergent biotopes. A suitable biotope requires food-supply, a safe hole and little disruption. The fox prefers meadows, but also woods, hedges and all sorts of vegetation. Foxes and fox territories can generally be found in nature but during the last decades, the fox has adapted himself to our constantly expanding human environment. The fox has managed to come and live closer to human environment and to take advantage of it in its own way. The fox is a true opportunist and human environments (parks, suburbs,...) are often a source of food to the fox (rubbish, scraps of food on dunghills...but also rodents that are found near to farms f.e., and also free-range poultry). A nice example of such a fox territory is Kraainem (near to Brussels). There is a den at less than fifty metre from a residential area and at less than ten metre from the motorway E40, and even less then 2 km from the heart of Europe. Unfortunately, the inhabitant of that den died in may 1999, but this loss will soon be repaired in a natural way.

Foxes use the smell of their excrements to mark out their territory. Smell is (in addition to body language and sounds) an important means of communication in the world of foxes. A fox has a few smell glands (the anal gland on the tail, the glands in the corners of the mouth, between the pads on the feet and the anal glands) that spread a smell, that is typical of the individual and through which a fox consciously (holding tail with anal gland up in the sky, marking preys by rubbing along them with the corners of their mouth,...) and unconsciously makes its presence known to other foxes. Smell also plays an important role in the search for food, the following of animals of prey and other foxes and in tracking down ennemies. The shouting of a fox is probably one of the most frightening sounds that one can hear during a walk at night. Foxes have a whole repertory of sounds. The most frequently heard sound is the shrieking, hoarse howling and the typical 'wow wow wow' call especially of vixen in the mating season. By barking, vixen want to make known their presence to a possible partner over a long distance. They can also warn their offspring to a possible danger and/or mislead that danger by using different sounds (usually a hoarse barking or a shrill howling). When confronted with other foxes, foxes use body language sometimes combined with a soft snarling to reveal their state of mind. They will behave playful, submissive, superior, aggressive,...towards the other members of the group. An anxious fox f.e. will push its ears backwards and flatten them and hold its head somewhat downwards, an aggressive fox will do the same but it will keep its snout wide open and produce a typical sound.

Although sometimes active during the daytime, foxes are mainly nocturnal animals. One of the reasons is that most of the animals of prey are also active only during daytime. Another reason is that at night the earth cools off and smells cling longer. And as we know, smell plays an important role in the tracking of preys. The eyes of a fox are extremely sensitive to light. The elliptic upright pupil can admit on the one hand a lot of light during dark so that foxes have a perfect view at night. On the other hand, this pupil protects the sensitive eye against blazing daylight. Also hearing is important. A fox can hear the squeaking of a mouse at a long distance. When hunting little rodents, foxes use a special technique: once they've heard a promising sound, they head for it, but not always successfully: it's often difficult for a fox to find the exact location of a mouse while walking through high grassy fields at night. In that case, the fox will use its hearing: it will turn its head back and forth and will use its big auricles as a kind of antenna to locate the mouse exactly. While localizing the mouse, the fox will expand its body so that it -when it has localized the mouse- can jump high and land exactly on the prey with its forepaws, grab it and eat it as quickly as possible.

A fox is a true opportunist. It will eat everything that is fit for consumption. The menu of a fox consists mainly of rodents and little to medium-sized animals of prey (rabbits, hares, poultry, moles,...) but also bait, forest fruit and insects is on the menu. The choice of food also depends on the biotope. The fox makes itself useful and indispensable in nature by eating the surplus of animals of prey. The fox makes a natural selection out of these animals of prey that also benefits the hunted species: it chooses the weakened, aged or sick animals. Foxes normally bury the surplus of scraps of food. They do that by first digging a little hole, then putting the prey in the hole and finally covering it with earth. Foxes will find the place where they left these scraps by using their memory and their sense of smell. Within one territory, scraps of food are hidden on a place, known to all foxes in that territory, so that they, if hunting yielded nothing, can eat some of the scraps.

Foxes mainly take shelter in a hole that they dig themselves. But these holes can also be former rabbit or badger holes. Also other shelters are interesting to foxes: an abandoned hay-loft, a car wreck,...all places that make a fox feel safe (in other words, places that are not accessible to people and their pets), that protect it against all sorts of weathers, and where it cannot be disturbed. It's not clear to what extent foxes really use these shelters. They are certainly used for giving birth to cubs and for raising them. In the daytime, foxes often sleep outside, but bad weather conditions lead the fox to one of the shelters in its territory. If foxes have cubs, the tiniest disturbance (f.e. a simple visit of human beings) will lead to the removal of the family to another shelter.

After a bearing time of 53 days, the cubs are born in the early springtime (march-april). One litter consists of five cubs on an average (the precise number depends on food offer and population density). The cubs are completely blind and deaf when they are born, they weigh approximately 100 gram and they have a black and woolly fur. The typical tailtip already has a white colour. During the first two weeks, the cubs stay close to their mother because they are not yet able to regulate their own body-heat. The vixen only leaves the shelter for a while for a comfort stop. During this two-week period, the dog fox and/or the other foxes in the group bring food to the vixen in the shelter. They announce their arrival by a low, silent barking. After they have brought the food, they immediately leave the shelter because the vixen doesn't like visitors while taking care of the cubs. After two weeks, the dark-coloured eyes of the cubs open and they begin to hear things. After four weeks, the cubs already make little expeditions in the neighbourhood of the den. The vixen keeps a sharp eye on them; she barks to warn reckless cubs and she often has to bring them back to the shelter. The cubs also communicate with their mother by producing growling and miaowing sounds. If they are out of sight of their mother and the other foxes, they start to bark quietly but loudly, so that the others know where they are. The vixen will now slowly begin to suckle the cubs while standing up. The cubs also begin to eat more solid food that the vixen has thrown up or little dead animals of prey that are dragged to the shelter by the vixen, the dog fox or the other members of the group.

During the first half of June, the fox family leaves the underground den and looks for a shelter overground (like dense vegetation, blackberry bushes,...). The colour of the fur and the typical foxlike figure (big ears, pointed snout) begin to assume a definite shape. After six weeks, the fur and the figure of the fox are full-grown but the cubs aren't. The teeth of the cubs become too sharp so that the vixen will slowly stop suckling the cubs and the production of milk diminishes. The cubs make more and longer scouting-expeditions throughout the whole territory. They will follow their parents or other members of the group when they go hunting and in that way learn to hunt themselves. At first, the hunting isn't so successful and the cubs concentrate more on easy preys like worms, insects and mice. It's only in the beginning of autumn that the cubs are full-grown, fertile and independent. Most of the grown-up cubs leave the family in search of their own territory and a partner. Some of the cubs leave voluntarily, others are being chased away by their parents (this happens when the average number of foxes that balances a biotope is exceeded; this is directly determined by the food offer). There are also some cubs that stay and join the group. Dog foxes are always chased away out of the parental territory if they haven't already left themselves. For unexperienced, young and grown-up cubs there are some rough times ahead: although they are trained in hunting, there is still a raw season awaiting them. The search for their own territory and a partner will not be without any danger: quarrels with other foxes, the mortal traffic and most of all the hunting trips (plezierjacht?) will mean death for a lot of these young grown-up cubs. Around autumn (= in deze tijd van het jaar?), the population of foxes is on the move. Roaming foxes cover enormous distances, former occupied territories and new territories are being explored and taken. As a result, foxes turn up in the most unlikely places. But foxes will only stay in these places if they think it's suited to them. Courting foxes set out scent marks (urine) and cry to each other over a long distance. On a late autumn or winter night, you can sometimes hear a real concerto of a long-drawn out, shrill howling. If a dog fox and a vixen have found each other, they will stay side by side until mating time. Their relationship is monogamous: a dog fox and a vixen stay loyal to each other until one of the partners dies. Although the mating urge of a dog fox is three months, a vixen is only ready to mate during three days. When the vixen produces a special smell, the dog fox knows that she is ready to mate. If a dog fox tries to approach the vixen sooner, it will be rejected by her. During these three days, both partners mate several times. After the mating, the vixen will search for a proper den to give birth to her cubs. That ends the annual cycle.

Hans Schockaert