BBC News Online: Sci/Tech

Foxes learn aversion therapy over lunch

The enforced aversion therapy works on the same principle as drugs that make alcoholics feel ill as soon as they start drinking.

Trials on five foxes have proved the theory can be applied to animals, the National Scientist magazine reported.

A year after being fed a single meal of pheasant laced with a nausea-inducing drug, the foxes still refused to try the bird again.

Dr David Cowan, of the Central Science Laboratory, said the effect was observed even when the foxes showed no external signs of illness induced by the drug.

"Two of these animals were sick," Dr Cowan said. "The others showed no obvious signs of illness and a few hours later were eating their normal food.

"Over the next year we repeatedly presented them with pheasant meat again and all of them consistently showed active signs of avoidance. They'd go up to the pheasant meat and sniff it, shake their heads vigorously and retire.

"One of them repeatedly urinated on it. Another one covered it up with wood shavings and the others turned the bowls over. They're actively avoiding this meat and that has gone on for a year."

The next stage is to make the foxes link the dead meat they spurn with a live pheasant.

The team working on the project believes it may be possible to make them do so, although it has not yet succeeded.

Even then, Dr Cowan admits, aversion therapy can only really offer protection to animals hunted by territorial predators.

If a territorial group is trained not to eat an animal it will also protect it from other intruders.

Dr Cowan said: "If you use culling to remove territorial predators, they're generally very rapidly replaced, either by expansion of adjacent territories or by immigration.

"The beauty of our approach for a territorial animal is once that animal has been trained to avoid a particular prey in its territory, it will be in effect protect all those prey in its territory from intruders. So we'll be turning the poacher into gamekeeper."

Trials are now to begin on wild foxes that live in British nature reserves and eat rare birds such as sandwich terns and avocets.

If these are successful, Dr Cowan hopes to see his team's method adopted around the world.

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