What makes animals the enemy?

This weekend saw two articles tackle the hot topic of the (re)introduction of species from quite different perspectives.

In the New York Times Felicity Barringer explains how Yellowstone's grey wolves have been given fresh legal protection. Wolves were reintroduced into the park in 1995. Previously they could be hunted legally, now plans to allow around 500 wolves to be killed across three states are on hold.

Meanwhile The Observer's Robin McKie reports that Chile and Argentina are mounting an enormous operation to eradicate thousands of North American beavers that are chewing their way through the countries' forests. Fifty beavers, a species not native to South America, were introduced in the 1940s and over the years that followed the population has snowballed.

There are lessons to be learnt from both stories: the trouble is deciding which lessons.

The reintroduction of large predators such as wolves is always going to be controversial but the question is who should decide 'how many is too many'? Without agreement between local people, government and conservation groups about what size of population should be maintained any animal reintroduction risks stumbling into an ethical and legal minefield.

South America's beaver problem is very different: the beaver after all is an alien species, as such the local ecosystem is not adapted to cope with it. Reintroducing European beavers to the UK doesn't carry the same level of risk as, until recently, beavers were native to these shores and our ecosystem should be more robust.

The difficulty, perhaps, comes in our rather inconsistent attitudes to wild animals and their impact on the environment.

In the UK there seems to be a consensus we should conserve wild habitats and wild populations wherever possible. Yet what if, in the long-term, this is only possible if such habitats are transformed or recreated? Or if wild populations are culled and managed rather like domestic livestock - does this mean these animals are no longer wild? Who is legally responsible for what these animals get up to?

As ever, the only answers lie in a better understanding of ecosystems and how we can best balance the needs of animals and humans.