"On biodiversity, it is time for a wake-up call and we have to issue a serious warning about what is going on. The earth is losing its capacity to sustain life," said EU Environment Commissioner Margot Wallstrom, ahead of a major conference on biodiversity to be held in Madrid next week.

"It's a very delicate system that we are able to upset. We need the ecosystem to be able to function: if we destroy it, it will be a disaster for us," she told reporters.

EU leaders have pledged to halt the loss of Europe's rich and varied wildlife by 2010. Wallstrom said much more needed to be done to achieve what she recognized was a very tough target, with little in the way of indicators to monitor progress.

Birds were perhaps the best indicator of losses in biodiversity as they were high in the food chain and could reflect changes in ecosystems, she said. Although abundant enough to be accurately monitored, numbers of common farmland and woodland birds are at just over 70 percent of 1980 levels.

Urban sprawl, intensive agriculture and dense transport networks were just some of the factors that had helped eliminate Europe's wildlife habitats, Wallstrom said.

The latest threat was global warming, which scientists say could wipe out more than 35 percent of all species by 2050.

"Threats to biodiversity have to do with habitat loss, the way we use land and are to do with climate change," she said.

One of the best-known examples of a species near to extinction is the Iberian lynx, which is becoming critically endangered as its natural cork-forest habitat dwindles.

Only a few hundred of the nocturnal leopard-spotted cats are left in a few isolated pockets in Spain - a country which Wallstrom said had the most biodiversity in Europe.

Until recently, it was thought that some 1,000 Iberian lynxes - distant cousins of the American bobcat - prowled the grasslands of southern and central Spain and Portugal.