AT THE 1992 Earth Summit in Rio de Janero, we signed up to the convention on biological diversity. This gives us a legal duty to take action to conserve and enhance biodiversity.

An important new paper "The rise of the mesopredator" has been published in the journal Bioscience which highlights how the loss of apex predators such as wolves, bears and lynx causes biodiversity loss.

This occurs because these animals limit the numbers and range of mesopredators such as foxes and also large herbivores such as deer.

When apex predators disappear, animals they prey on and compete with become over abundant.

This causes a loss of biodiversity in the plant and animal communities they feed on.

The research found apex predators reduced fox numbers and also that animal behaviour was modified, having important consequences. Although this was in America, there is no reason to suppose this would not have occurred here too.

One way to rectify this would of course be reintroducing apex predators, but this is probably impractical. Given the furore about foxes attacking babies in London, imagine how the public would react to packs of wolves roaming the countryside.

If we cannot introduce animals to prey on them, we have a duty to manage foxes and deer to protect biodiversity.

Some in the animal rights movement deny the science behind this conclusion and the League Against Cruel Sports recently suggested deer should not be managed at all but allowed to increase until they die.

The consequences would be unnatural and calamitous for the welfare of the deer and the environment.

Giles Bradshaw

Rose Ash