Now you see them, tomorrow you won't: As part of this week's British Association festival, ecologists are focusing attention on the rapid extinction of many species. Malcolm Smith reports

Wildlife conservation has come a long way since the first formally protected area - Yellowstone in the United States - was designated in 1872 and the Shoshone, Crow, and Blackfoot, who had long inhabited the region, were given their marching orders.

Well over 8,000 internationally recognised areas for the protection of wildlife have now been established around the world. They cover 5 per cent of the globe's land area. There are another 40,000 or so protected areas that do not meet international standards but nevertheless contribute to habitat and species survival. Together, these regions bring the total land area conserved in some way to nearly 10 per cent.

None the less, species of plants and animals are dying out at a speed that far outstrips the rate of natural extinctions in the fossil record.

Here in Europe, much of the continent's wildlife is in serious trouble. According to the Council of Europe, more than half of Europe's fish species may face extinction. So may an estimated 42 per cent of its mammals and 22 per cent of flowering plants. Figures for insects, fungi and a host of lesser known groups are not available. Species are being lost through ignorance.

Today, as part of this week's Annual Festival of Science organised by the British Association for the Advancement of Science, the British Ecological Society is devoting a full day's conference to the subject.

Not all is doom and gloom in Britain and Europe. Not since the last great auk was clubbed to death by fishermen in 1844 has any European bird species gone extinct. (That statistic doesn't embrace the Canary Islands and Turkey where, according to Birdlife International, the Canarian black oystercatcher and the northern bald ibis, respectively, are considered lost.)

Many birds have increased in abundance over the past few decades. Collared doves have spread west across Europe to colonise most of Britain. They were unknown here only a few decades ago. Almost all of Britain's birds of prey are on the up, recovering from the blight of pesticides in the case of sparrowhawks and peregrines, or benefiting from improved breeding success, less persecution and some reintroductions in the case of red kites.

But 'Across Europe', says Birdlife International's Graham Tucker, 'there are severe declines of birds of agricultural habitats and of many that depend on large insects for food. Shrikes, the European roller, lesser kestrels and bustards in Iberia, wryneck in Britain and many others.' Habitat destruction and pesticides play a major role in these declines.

In Britain, the magnificent red- backed shrike has almost certainly been lost as a regular breeder. It has been declining and contracting its range to the east of England for years.

More relevant to the wider public is the enormous decline in birds that were once commonplace. Tree sparrows (not the ones around our houses) have declined by 85 per cent, corn buntings by 76 per cent, partridge by 73 per cent and skylarks by more than half, all in the past 20 years.

Many of these birds were once characteristic of farmland, but have been tipped into decline as a result of changes in agricultural practice - particularly the switch to intensive farming. Hedgerows have beeen uprooted and flower- rich pastures ploughed and sprayed in an orgy of agricultural over-production.

The same boom and bust mentality afflicts our oceans and seas, treated by competing fishing fleets as if it were an endless supermarket shelf. Sea birds, and sea mammals such as dolphins, suffer as a result.

Declines in insects, and many other invertebrates, are poorly recorded, especially compared with birds. English Nature reckons that at least 156 species of invertebrates known only in England have become extinct since 1750. Two others are extinct in England but still occur elsewhere in Britain. A further 17 species are thought to be extinct in England but their status in other parts of Britain isn't clear. Many of these extinctions are of beetles, but also include dragonflies, mayflies and caddisflies. And because records are so comparatively few and far between, English Nature's figure may well be an underestimate. Many other insects haven't been recorded since 1970, including 226 different species of beetle. But no one wants to confirm that they have gone until they are sure.

When it comes to our seas, we know even less. Britain's seas have around 8,000 species of plants and animals. The distribution and abundance of many is, at best, poorly known.

Yet we know more about the plants and animals of Britain than we do of any other country in the world. Spare a thought, then, for Laos or Madagascar, which, along with much of South-east Asia, Australasia, Africa and South America, harbour a richness of plant and animal species that make the Dorset heaths seem desperately boring. Britain is home to only about 3 per cent of the world's known species.

Not that humanity has every species' extinction on its conscience. Just the vast majority. The San Benedicto rock wren, for instance, hasn't reappeared since

a volcanic eruption in 1952 destroyed its habitat.

Hunting has done for many species, particularly attractive and edible ones such as parrots, the dodo and passenger pigeon. Our introduction of predators and disease has done for several flightless birds. Introducing competitors for the native animals, such as rabbits in Australia, has had a major impact, too.

Then there is direct habitat destruction. Forest felling, drainage of wetlands, the urbanisation of coastal land, and the intensification of agriculture have all had an enormous impact. The worst period for extinctions since 1600 was the late 19th and early 20th centuries when Western so-called civilisation made its greatest inroads in the remotest parts of the world. For our times, the vital question now is: are we losing species faster today than at any other time?

Unequivocally, yes, argues Professor Bob May of Oxford University. 'Globally, about 100 bird species, for instance, have gone extinct in the last century,' he says. 'In the fossil record, the average life span for a species is between 1 and 10 million years. So recent extinction rates are very far in excess of what happened in the past.'

Merely designating protected areas, even if they cover up to a tenth of the world's land, is not enough to stem the losses. More protected areas, and their better management to conserve habitats and species - a plank of the Convention on Biological Diversity signed in 1992 at Rio - are essential. But more species exist on agricultural, forestry and other human-dominated land than in protected areas, simply because they cover around 80 per cent of the world's land area.

Changing the ethos of agricultural land, forest and fishery management away from quick-buck exploitation is as essential in Britain as in the Amazon basin. We are treating the planet on which we live as both sewer and supermarket. The best guarantee that we ourselves might survive in the long term is to ensure that the planet remains habitable for all the diversity of the living world.

(Photographs omitted)