many, MANY mainstream&powerful conservation organizations subscribe to a deeply flawed, colonialist philosophy: that in order to protect nature, it must be kept away from human hands.
The term often used to describe this is "fortress conservation" ; areas of interest are identified, all people living on this land are (often violently) forced off their land. The loss of indigenous caretakers allows illegal poaching , charcoal, mining (etc) to move in, and the indigenous people are used as scapegoats to allow these illegal destruction to continue... cause they slips money to conservation orgs and government. Across the board, conservation of this manner has resulted in human rights abuses, and imperils the nature it claims to protect.
guilty organisations:
WWF - World Wildlife Foundation / World Wide Fund for Nature
IUCN - International Union for Conservation of Nature
WCS - World Conservation Society
UNESCO - United Nations Educational, Scientific and Cultural Organization
Consider supporting orgs that support indigenous people instead...
Survival International
Rainforest Foundation UK
Happy to provide examples -- there are many -- just ask about a specific org mentioned here.
sources:
Decolonize Conservation: Global Voices for Indigenous Self-determination, Land, and a World in Common. Edited by Ashley Dawson, Fiore Longo, and Survival International.
list is NON EXHAUSTIVE and will update over time...