Rodrigo Camara Leret, a research scientist at the University of Zurich, has a neat way of explaining why engaging with indigenous peoples is important in maintaining the world’s biodiversity.

“If the rainforest is a library,” he said in a chat with Future Earth, “then the indigenous people are the index.”

Although there is no perfect definition for indigenous peoples — who include everyone from Inuits in the Arctic to Pygmies in Africa and hunter-gatherers in the Philippines – the World Bank says there are 370 millions of them.

That’s only 5% of the world’s population, but their impact on biodiversity is huge, given where they live – across 28% of the Earth’s landmass. The land inhabited by indigenous people in Papua-New Guinea alone, for example, contains about 5% of the world’s species, even if they themselves represent only 0.1% of the world’s population.

Camara Leret, who specialises in indigenous knowledge, reckons the world can learn a lot from indigenous peoples when it comes to biodiversity. He is not alone in this, of course, but in a presentation to the World Biodiversity Forum in Davis, Switzerland, he talked about three opportunities and challenges.

First, we can learn from indigenous people, and not just things such as which plants cure which diseases. There are differences in emotional and philosophical approaches.

“In the Amazon, many people relate to animals not as entities that are foreign to them (as in the West) but as entities that represent people of the past,” he said.

In an earlier presentation at the Forum, Berta Martin-Lopez, a professor in sustainability science at Germany’s Leuphana University, had noted that some indigenous inhabitants in the Andes got permission from the mountain before tapping a water supply. Is this, perhaps, a mystical version of an environmental-impact statement?

Camara Leret’s second theme was more of a challenge – visibility. This did not just mean getting the scientific world to pay attention to indigenous peoples. It also meant finding ways to tap into what they know.

“A lot of policy is based on publications, mostly written in English,” he said. This narrows the scope of learning, given that there are 7,000 languages in the world, many of them obscure. Furthermore, once a language is lost, as is happening with some indigenous tongues, you lose all the information held by that language.

A third challenge was scale. The information out there in indigenous communities is vast and it is hard to get a grip of how it relates to other information on a local, regional and structural level.

The index, in other words, is a tome and there may be many and different volumes of it elsewhere.