The Ferret our Unlikely Friend

by Read Listen Learn

If you look at Roman murals or medieval paintings that show different hunting scenes, always a popular subject, you will sometimes see pictured both men and women carrying nets, and what look like long, thin cats, as they walk towards a rabbit warren to clear it out or, maybe, just take a few for food. Other scenes may show one of the people pushing the cat-like creature into one of the holes of the warren as, elsewhere, rabbits are jumping out of the other holes into the waiting nets that cover their escape route.

The animals we see in these ancient hunting scenes are not any kind of cat. They are ferrets: members of a family of animals which includes the polecat, a wild ancestor of the ferret, and so closely related that even DNA analysis has failed to show that they are different species.

The polecat is a small but very aggressive predator that hunts smaller animals like rats, mice and birds. It likes to eat them whole, including their fur and teeth. There are a number of different types of polecat around the world but the one that was domesticated into the ferret is, basically, the European polecat. Although the European polecat originated in Western Europe hundreds of thousands of years ago, it has become common in North Africa and the Eurasian plains.

These little hunters were too small to present any real danger to humans but their ability to empty a rabbit warren in seconds was soon noticed. Roughly two and a half thousand years ago, or more, human beings began to domesticate and keep polecats. This was almost certainly for hunting. With time, the domestic polecats, or ferrets, changed slightly in size and colouring but remained perfectly able to cross-breed with their wild cousins.

These newly domesticated animals soon became very useful, especially to the common people. In those days, the forests were full of deer and bison but it took a rich man with servants, horses and dogs to catch and kill such large creatures. The peasants, men, women or older children only needed a few nets and one or two ferrets to catch hundreds of rabbits at a time. Ferrets were soon making a big contribution to the protein in the diet of country people. And, there was also work for ferrets in the towns and cities that were beginning to appear everywhere. Rats in urban centres were becoming a health hazard and a pest as they stole from human food stores and spread disease wherever they went.

Ferrets, again, were the ideal answer. Just one or two could be sent into rats' nests behind walls, in roofs and under floors. The ferret's thin body and very narrow head make it easy for it to pass though tiny gaps; its very sharp teeth and its bloodthirsty temperament mean that no rat will stay and fight while there is a chance of running away. And, so, the rats would run – into the waiting nets of the rat-catcher, or the strong jaws of small dogs set to catch the vermin as they emerged.

Of course, the rats, little by little, would always return but sometimes even the sharp, acrid smell of the ferrets' urine would be enough to keep the rats (and probably many humans) from making a return visit. Rat-catchers, their dogs and their ferrets were a common sight in cities until about a century ago. (They've been replaced by better traps and better poisons.) And, of course, rabbit-catchers, also with ferrets and dogs, can be seen in the countryside even today.

But, there's more to ferrets than just hunting rodents. As their use in pest control has declined, so they have become more popular as pets. They are certainly very cute, with their little faces and white or creamy brown fur but, they can give a nasty bite; and there's still the problem of that unpleasant smell.

Less happily for ferrets, they share certain metabolic points in common with human beings and this makes them ideal for medical research, especially on new kinds of flu. So, they can be very useful to people in a number of ways but they are not always welcome everywhere.

In the late nineteenth century, both ferrets and wild polecats were introduced into New Zealand to help cut down on the number of feral rabbits that were destroying crops and gardens, and the natural balance of these islands. Ironically, the rabbit had also been introduced by the same European colonists. They now hoped that other 'guests', the ferret and the polecat, would get rid of the plague of rabbits; which they did.

Rabbit numbers soon dropped to acceptable levels but, the ferrets and polecats, victims of their own success, were left without an easy food source and went on to ravage the small fauna of New Zealand. The kiwi, a flightless bird that is the national symbol, was especially vulnerable and came close to extinction. All in all, it was an ecological disaster; and similar stories unfolded across the globe as the ferret was taken to different continents. Now, not just New Zealand but also Australia, Brazil, Portugal, the U.S.A. and Japan have all introduced strong laws banning ferrets or requiring them to be 'doctored' if they are kept as pets.

Once, the ferret played a key part in keeping the natural order in towns and countryside but, now, it is seen as a serious ecological threat.