Peoples that have lived self-sufficiently for centuries have been forced to give up hunting and farm only in designated areas in order to make way for eco-tourists and schemes aimed at preserving endangered species.
Survival International said last night that conservation groups were now becoming as significant a threat to the existence of tribal peoples as large corporations and oppressive governments.
The Worldwide Fund for Nature (WWF) refuted the criticisms saying that it no longer practised "eco-colonialism" and that local people were being involved in all new parks projects.
Survival claimed that in the Philippines, the survival of the Tagbanwa and Batak peoples, who now number less than 1,000, is being jeopardised by plans to expand St Paul's Park, a nature reserve which was originally set up by the WWF.
Some Batak people have already been expelled from the site and the expansion would lead to a ban on them farming their lands, it said.
Another project set up by the WWF, the Korup national park in Cameroon, has led to the displacement of the Korup people, after bans on hunting were imposed. The park is designed to protect the red corobus monkey and other species.
Survival also criticised Conservation International, an American organisation, for setting up a project in Surinam to scour the jungle to find them medicinal plants for use in the pharmaceutical industry.
It said the local people, the Saramakaner Maroons, could not read or write and had no knowledge of international property rights.
The pattern for excluding native people from conservation parks was set by German zoologist Professor Bernhard Grzimek, an outspoken champion of the Serengeti National Park in Tanzania, who declared: "A national park must remain a primordial wilderness to be effective. No men, not even native ones, should live inside its borders."
Other conservation groups have shown a willingness to work with governments which have appalling human rights records for the treatment of their indigenous peoples.
In Burma, the junta has been seeking to improve its environmental reputation by working closely with the Wildlife Conservation Society, and the Smithsonian Institution, two of the world's top names in wildlife protection.
To make way for what is planned as the biggest nature reserve of its kind in the world, the Burmese army is currently driving the native Karen people from their jungle homelands and razing the area.
In Sri Lanka, the preservation of elephants and leopards has been identified as the priority of the Madura Oya National Park where the presence of the Veddahs, the indigenous people of the island, is now illegal. The park was set up in consultation with the United Nations Environment Programme.
Tricia Barnett, director of pressure group Tourism Concern, said: "Local people have for many years been evicted from their homes because they have not been considered responsible enough to maintain their own environment.
"Where conservationists go, tourists follow but the local people cannot."
Richard Garside, spokesman for Survival, said: "People are being forced into economic and social hardship as a result of a bizarre idea of environmentalism.
"We all want a globe which is less polluted but conservation groups have got to realise that the people themselves have a stake in the environment in which they live."
Last year, the WWF, which concedes it may have had more of a paternalistic approach to tribal people in the past, published a position paper to stress its commitment to a fair relationship.
It said: "The Worldwide Fund for Nature recognises that indigenous peoples have the right to the lands, territories and resources that they have traditionally owned or otherwise occupied or used and that those rights must be recognised and effectively protected."
Cherry Farrow of WWF said that the group's work was no longer just about conservation but also attempted to alleviate poverty among the local population.
She said: "All of our work with national parks integrates with local people so that effectively they become guardians of their own resources.
"You don't manage anything if you alienate people."Reuse content