As mentioned earlier, fox´s have relatively small stomachs for their size. Consequently, a red fox can eat only about half as much food in relation to it´s body weight as wolves and dogs can (about 10% versus 20%). They therefore must eat much more frequently than their larger cousins. Unfortunately, the vagaries of predatory life work against a fox being able to expect meals on a regular basis. Bad weather, scarce food supplies such as in winter months, injuries, and plain bad luck could cut off its food supply for some time. On the other hand, there are times when food so plentiful, a fox can´t hope to eat it all. It is during these periods that the fox will cache food as an insurance policy against starvation.

Not only will the fox save leftover food in its caches, it also hunts regularly with the sole intent of storing the kills for later. There are very few variations between caching technique among individuals. Simply described, a shallow hole 5-10cm deep is dug, the food item (usually only a few mouthfuls) is dropped in, and is then carefully covered. The entire process takes only about a minute and a half. Photographs that I´ve seen of buried caches show an amazing degree of camouflage to prevent them from being stolen by other animals.

Rather than storing all of its food in one central location, foxes tend to build as many small caches as possible, and scatter them across their territories. The most important reason behind this behaviour (as opposed to hoarding behaviour seen in other animals) is to prevent a catastrophic loss of the fox´s entire food supply in the event that another animal finds the store. Any minor losses suffered are generally recouped by raiding the stashes of neighbouring foxes. (One thing I found to be really interesting is that this apparent thievery amongst foxes is actually communally beneficial as fewer of the hidden stashes are forgotten about and lost forever, thereby increasing the overall food supply; mutual theft for the good of all- Now that´s a great lesson for us humans!)

A lot of fascinating studies have been done to determine just how these stores are relocated. While the food is buried shallow enough for it to be smelled at short range by an animal that knows its there, it is too deep for the scent to be carried far. Despite this, foxes still manage to recover a large portion of their caches, apparently by remembering their location. (This is quite remarkable given the large number of caches made, and the vast area available to hide them in.) The depth at which the food is buried seems to be an effective tradeoff between the need to keep it hidden, and the need to supplement memory with olfactory cues. The result of these studies is that it has become clear that foxes have fantastic memories.

Foxes, of course, are not the only canines that exhibit some form of caching behaviour. My dog likes to cache dog biscuits and toys between the cushions of the couch, almost exactly in the manner described. Its very serious business to her, and great fun can be had at the sight of the dirty looks she gives you when you straighten out the furniture.