Rich countries must pay much more to save endangered creatures and their homes from extinction, UK conservationists say.
By Alex Kirby
BBC News Online environment correspondent
Despite international agreement on conserving biodiversity, they argue, animals, birds and plants continue to vanish.
They say the developed world has failed to live up to its promises to pay to slow the damage.
And they damn it as immoral for leaving the poor countries to shoulder the burden.
The criticism comes from the Royal Society for the Protection of Birds (RSPB), which is seeking agreement on a new, legally binding international commitment to provide funding and safeguards for a network of protected areas.
It says this is needed to stem "the unprecedented loss of the world's biodiversity and ecosystems".
The RSPB's call comes at the start of a meeting in London of the United Nations Convention on Biodiversity (CBD).
Basis of life
The meeting is reviewing progress towards the target of "a significant reduction in the current rate of biodiversity loss by 2010", agreed at the 2002 World Summit on Sustainable Development in Johannesburg.
Human health, economy and existence all rest on the planet's ecosystems, the RSPB says: rainforests, savannah and coral reefs all provide water, contribute to soil formation, regulate climate and filter air.
They also provide plants for food and medicines for local communities, and support bird and animal life.
The great Indian bustard: Globally threatened (Image: Asad Rahmani)
The RSPB says the countries with the richest biodiversity are having to struggle to save it because they are so short of money.
It says: "Despite the promises made by the industrialised world to provide financing for biodiversity, this has not been forthcoming.
"An increase in environmentally destructive human activities - illegal logging, ineffective management and burgeoning pollution - combined with a lack of political will and money means species and areas originally designated for protection are being disrupted and destroyed."
Alistair Gammell, the RSPB's director of international operations, said: "The convention recognises that keeping our world's biodiversity is a common concern for all of humankind.
Transfer of resources
"However, the current completely inadequate level of international funding means the costs of conserving these enormously valuable resources is not a shared burden.
"It is too often being carried by many of the poorest communities - those who are least able to bear those costs.
"It's time for a radical rethink. If we agree the benefits to be derived from biodiversity are supra-local, then supra-local political bodies and institutions should shoulder a proportionate responsibility.
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"We need to help local people to become the custodians and managers of important places for biodiversity, without having to destroy them or face poverty."
Alistair Gammell told BBC News Online: "We're calling for a serious transfer of resources from North to South to fund conservation by creating this network.
"At the moment the greatest burden falls on those who live closest to protected areas.
"It's immoral and impractical to expect the poor to pay for conservation, and it isn't going to happen. So it's bad for conservation, and for poverty reduction as well.
"You get the worst of all possible worlds - either you leave people in poverty, or you're guaranteed to have continuing battles with them over safeguarding habitats."
In 2002 the CBD said 24% of mammals and 12% of birds were globally threatened.
One estimate of the cost of an effective global reserve programme on land and sea put it at $45 billion (£27.5bn) annually.
This, the estimate suggested, would deliver "ecosystem goods and services" worth up to $5,200bn (£3,170bn) a year.