Mark Dowie calls them "conservation refugees" and says (in Orion, found via The Uneasy Chair) there are millions all around the world. Governments have forcibly displaced them from their lands in order to establish nature reserves. "Conservation refugees" are victims of government abuse of property.
Dowie quotes Peter Seligman, CEO of Conservation International, as saying that "indigenous people must have ownership, control and title of their lands." That's the way to go (except that I think the word "indigenous" is superfluous, if not discriminatory -- everybody, regardless of race, ancestry or place of birth, should have the same rights). If someone (say, the Wildlife Conservation Society) wants to exclude people from a piece of wildland, then let it negotiate a price with the legitimate owners of the land. If they strike a deal both parties will be better off than before.
Lack of adequate property rights, including the right to voluntary sell the land, is not only detrimental to the people living in wildlands but also detrimental to conservation. People interested in conserving wildlands cannot buy lands that do not have rightful owners. Instead they have to rely on lobbying the governments that have the ultimate authority over those lands. In the end, governments assign some public lands to nature conservation, others to mining or timber extraction or whatever. Governments' decissions on these matters -- which and how much land goes to each use -- are rather arbitrary.