Ecology

Download the Nature Podcast 11 September 2024 In this episode:00:45 What ancient DNA has revealed about Rapa Nui’s pastAncient DNA analysis has further demonstrated that the people of Rapa Nui did not cause their own population collapse, further refuting a controversial but popular claim. Rapa Nui, also known as Easter island, is famous for its giant Moai statues and the contested idea that the people mismanaged their natural resources leading to ‘ecological suicide’. Genomes sequenced from the remains of 15 ancient islanders showed no evidence of a sudden population crash, substantiating other research challenging the collapse idea.Research Article: Moreno-Mayar et al.News and Views: Rapa Nui’s population history rewritten using ancient DNANews article: Famed Pacific island’s population ‘crash’ debunked by ancient DNA17:03 Research HighlightsThe extinct bat-eating fish that bit off more than they could chew, and how manatee dung shapes an Amazonian ecosystem.Research Highlight: Ancient fish dined on bats — or died tryingResearch Highlight: The Amazon’s gargantuan gardeners: manatees19:29 A macabre parasite of adult fruit fliesDespite being a hugely studied model organism, it seems that there’s still more to find out about the fruit fly Drosophila melanogaster, as researchers have discovered a new species of parasitoid wasp that infects the species. Unlike other parasitic wasps, this one lays its eggs in adult flies, with the developing larva devouring its host from the inside. The minuscule wasp was discovered by chance in an infected fruit fly collected in a Mississippi backyard and analysis suggests that despite having never been previously identified, it is widespread across parts of North America.Research article: Moore et al.32:04 Briefing ChatHow a dye that helps to give Doritos their orange hue can turn mouse tissues transparent, and an effective way to engage with climate-science sceptics.Nature News: Transparent mice made with light-absorbing dye reveal organs at workNature News: How to change people’s minds about climate change: what the science saysSubscribe to Nature Briefing, an unmissable daily round-up of science news, opinion and analysis free in your inbox every weekday.Never miss an episode. Subscribe to the Nature Podcast on Apple Podcasts, Spotify, YouTube Music or your favourite podcast app. An RSS feed for the Nature Podcast is available too. More

Profits from rooibos tea are being shared with South Africa’s Indigenous Khoi and San People, in recognition of their contribution to its development.Credit: Mike Hutchings/Reuters

For at least two decades, scientists, policymakers and journals, including Nature, have cited a statistic without determining its validity. The data point in question is that 80% of global biodiversity is under the stewardship of Indigenous Peoples. There is no doubt that Indigenous communities are core to the conservation of biodiversity, but to say that they are stewards of 80% of the world’s genetic, species and ecosystem diversity isn’t supported by evidence, as the authors of a Comment article last week stated (Á. Fernández-Llamazares et al. Nature 633, 32–35; 2024).
No basis for claim that 80% of biodiversity is found in Indigenous territories
A single, unsubstantiated number also does not reflect Indigenous values and world views, the authors add. There are better indicators and statistics on Indigenous communities and biodiversity, says Álvaro Fernández-Llamazares, a co-author of the Comment article and an ethnobiologist at the Autonomous University of Barcelona, Spain, in an accompanying Nature Podcast.Biodiversity — defined as the variety of life on Earth, including its variation at the level of genes, species and ecosystems — is extremely hard to quantify. Even the simplest statements come with great uncertainty: there is no consensus, for example, on the number of species on the planet1. There are at least 50 ways to value nature, according to researchers working with the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) in Bonn, Germany2.
Podcast: The baseless stat that could be harming Indigenous conservation efforts
The authors of the Comment article, three of whom identify as Indigenous, reveal that the 80% statistic seems to have emerged in policy reports, from which it spread into the scientific literature. As of 1 August, the researchers found the 80% claim mentioned in 186 peer-reviewed journal articles. The earliest mention that they found was in a 2002 United Nations document that said that Indigenous Peoples “nurture 80% of the world’s biodiversity on ancestral lands and territories”, without a citation. The number is repeated in an influential 2008 World Bank report.So why might this number appear in policy documents first? It stems from Indigenous Peoples’ centuries-old encounters with more-powerful interests, the resulting exploitation and mistreatment, their fight for rights, and the international community’s ongoing policy response.
Assessing the values of nature to promote a sustainable future
Worldwide, there are some 467 million Indigenous People across 90 countries. Today, they are among the poorest, most vulnerable and least protected people in their nations. Some international laws and modern research practices pertaining to biodiversity derive from the 1992 UN Convention on Biological Diversity. This agreement has its origins in a movement to create protected areas — ironically, areas often initially created by taking away Indigenous Peoples’ rights to land or expelling them. During the negotiation, representatives of low-income countries and Indigenous Peoples fought to ensure that the agreement included provisions for the equitable sharing of biodiversity’s benefits, such as profits from food or medicines.By the early 2000s, organizations such as the World Bank were working with Indigenous Peoples’ representatives, and examining the impact and legacy of their own previous lending practices on Indigenous Peoples and creating ways to involve them in their decisions.The research community also had work to do. When IPBES was established in 2012, it pledged, for the first time, to incorporate Indigenous and local knowledge in its global scientific assessments of biodiversity. Studies are now being co-produced between Indigenous and non-Indigenous authors. A next step needs to be more studies designed and led by Indigenous authors3.Around the world, the struggle for Indigenous rights has a long way to go. Researchers have a crucial role in supporting communities, which includes being rigorous with data. As Fernández-Llamazarez says in the Nature Podcast, unproven data risk fuelling scepticism on the role of Indigenous communities in biodiversity stewardship. More

At the end of July, a wildfire driven by extreme winds blazed through Jasper National Park in Canada, forcing the evacuation of 25,000 citizens and visitors. For a month, more than 350 firefighters worked to control the fire, which grew to cover 33,000 hectares, making it the largest wildfire in the park in at least 100 years. Last year’s fire season was also catastrophic: about 4% of the nation’s forest area burnt (15 million hectares) — more than twice the previous record, set in 19891.
‘Fire clouds’ from super-hot wildfires are on the rise as Earth warms
Wildfires are not always bad — they have been fundamental to forest ecosystems for hundreds of millions of years2, affecting the composition, structure and biodiversity of landscapes3. Some plant species, such as jack pine (Pinus banksiana) and lodgepole pine (Pinus contorta), require the heat and smoke generated by fires to release their seeds from a resin-coated cone and to germinate.But wildfires in Canada have been increasing in number, size and intensity since the mid-twentieth century4,5. This is mainly the result of anthropogenic climate change and the accumulation of undergrowth and other fuel after decades of fire suppression as a way to manage forests.The situation is dire, but not hopeless. In many parts of the nation, efforts are shifting from suppressing fires to a variety of responses, including lighting controlled fires to manage vegetation — often referred to as prescribed burning. Indeed, two decades of such proactive fuel mitigation in the forests surrounding Jasper has meant that firefighters were able to save around 70% of the town’s infrastructure after the July wildfire.

Credit: Sarah Smith-Tripp and Liam Irwin

As forest scientists and fire practitioners, we urge the public and those involved at all levels of forest management to think about fire more holistically. As humanity prepares for a future in which fires become more common, we need all the tools at our disposal. Two sources of knowledge that are often overlooked are crucial — Indigenous-led fire stewardship and technological advancements in data acquisition.Indigenous-led stewardshipHumans have used fire to influence landscapes for millennia6,7. Indigenous Peoples around the world continue to recognize the importance of fire stewardship to maintain desirable, diversified and resilient ecosystems and to achieve cultural objectives that have ecological benefits7.Many Indigenous communities use fires for a variety of purposes — from protecting nearby infrastructure and settlements to managing territories for crops, food and medicinal plants. For example, First Nations communities across Canada use fires to boost the abundance, productivity and nutritional value of huckleberries.

Forest regrowth after a wildfire in British Columbia in 2017.Credit: Liam Irwin

Wildfire agencies in Canada are beginning to show an interest in incorporating Indigenous fire practices — known as cultural burning — into forest landscape planning processes. For example, the We Are Fire project involves Indigenous knowledge holders using cultural fire practices to improve biodiversity in the Saskatchewan River Delta.
Are we all doomed? How to cope with the daunting uncertainties of climate change
Crucially, cultural burning is not something that can simply be captured and appropriated into plans by agencies to inform wildfire management7,8. Indigenous communities, which hold the cultural, technical and place-based expertise to engage in both proactive fire stewardship and wildfire response, must lead these processes and make decisions according to their cultural and ecological values9. This is all the more important because Indigenous Peoples disproportionately bear the burden of wildfire impacts through evacuations, alteration of their territories and other adverse effects on their ways of life10,11.Not everyone is convinced by the usefulness of prescribed and cultural burning, however. Some doubt the ability of public authorities to control the fires, and worry that, in a rapidly warming and drying climate, the risk of a fire ‘escaping’ beyond its intended area is too high. Such accidents can erode public trust. Research is needed to better understand and address this resistance. Practical restrictions also exist regarding who is allowed to ignite fires, who is responsible for each event and who can approve and oversee the processes12. Forest and landscape management planning processes must be revisited.

Wildfires are becoming more frequent and more severe in British Columbia.Credit: BC Wildfire Service/Xinhua/Alamy

The first steps must be to accelerate capacity in Indigenous communities to participate in, and lead, wildland fire management. There should be more communication, joint training — and, importantly, overlap — between Indigenous fire practitioners and wildfire agencies to share knowledge of fire behaviour and its effects in a respectful way. This will help communities to devise practices that are grounded in cooperative and considerate fire management8,13. Although the Canadian government has piloted programmes and grants that focus on training and collaboration, more permanent funding sources are needed to ensure continuity of these successes.Measure, monitor, modelAdvanced technologies should also be used more widely. Remote-sensing data from satellites, aircraft, hand-held devices and drones can be used at all stages of fire — before, during and after the event14.Satellite data have long been used to track land cover and changes brought on by fire. They can also help to determine pre-fire fuel loads, monitor recovery and identify areas that are less prone to burning. Known as refugia, such areas are valuable for regeneration after a fire and for conserving biodiversity. State-of-the-art technologies can map in exquisite detail the state of forest fuels, including species composition, soil moisture, vertical structure and connectivity, hotspots and vegetation health.
How record wildfires are harming human health
Future satellites will do even more. For example, WildFireSat, a joint programme involving three Canadian federal agencies that is expected to launch in 2029, will be the first public satellite mission to be purpose-built to monitor wildland fire. It is designed to observe fires at their peak — typically during the afternoons, when temperature, humidity and wind are most conducive to fire activity — to track their boundaries and spread. It will also be able to measure radiative heat power, so that resources can be prioritized to the most intense fires, particularly in remote, northern communities in Canada, where early and safe evacuations are crucial. Researchers can improve models that measure emitted carbon and track fire spread to help reduce economic losses and improve public safety.In the past decade, drones have helped to characterize the structure of forests in great detail — including fuel loads and proximity to or connectivity between trees. They do this by, for example, measuring sunlight reflected from Earth’s surface and gathering topographic data by emitting laser pulses and timing their return to a sensor. Such light detection and ranging (lidar) instruments can draw a 3D picture of fire-fuel distribution by mapping forest height, cover, species and crown attributes. Photographs from drones can assist firefighters and be used to help regenerate disturbed ecosystems after fires15. Linking such drone-based data with fuel metrics — the amount of understorey material, such as shrubs and grasses, that is present — is currently under way.

A worker watches a prescribed-burn site at High Park in Toronto, Canada.Credit: Lance McMillan/Toronto Star via Getty

Drones with on-board sensors are becoming cheaper — from hundreds of thousands of dollars a decade ago to a few thousand today. Their controls, mission-planning software and safety features have improved. And processing techniques are advancing, for example through machine learning and other types of artificial intelligence. These technological advances are beneficial only if they reach all relevant users, however, and they require users to be trained.Come togetherConversations led by Indigenous Peoples and involving researchers and other knowledge holders must happen urgently, so that local management strategies can be devised. And international collaborations — between scientists and policymakers as well as between disciplines — are a top priority that would help to mitigate the rise in the number and intensity of North American wildfires. This will require a huge effort, but there are precedents. In the 1980s, after the discovery of a ‘hole’ in Earth’s ozone layer over the South Pole that posed a major threat to human and environmental health16, leaders worldwide agreed on the Montreal Protocol. Its aim was to phase out the use of ozone-depleting substances, such as the chlorofluorocarbons commonly used in spray cans and refrigerants. In doing so, they averted the collapse of a global Earth system. Now, there is evidence that the southern ozone hole has recovered and that ozone levels are on track to return to pre-1980 levels by the middle of this century17. Cross-border arrangements such as the US–Canada Air Quality Agreement also showcase success and opportunities for collaboration.The same level of international urgency is needed for wildfires. Environmental assessments must be done, both domestically and across borders, to explore how to mitigate fires and coordinate efforts. At local or regional levels, ‘conservation economies’ should be put in place, in which members of a community are employed to protect carbon and biodiversity. Existing Indigenous ‘guardian programmes’ should be supported, including financially, and expanded.Wildfire is a crucial ecosystem process. Proactive management led by Indigenous Peoples and supported by advanced technologies is key to decreasing fire risks and increasing resilience in forests. Only with such a change in perspective can forests be protected in Canada and beyond. More

RESEARCH HIGHLIGHT
07 September 2024

The aquatic mammals disperse seeds of their favourite foods as they migrate, according to a serendipitous study of their poo. More

Download this episode of the Nature PodcastThe often repeated claim that “80% of the world’s biodiversity is found in the territories of Indigenous Peoples” appears widely in policy documents and reports, yet appears to have sprung out of nowhere. According to a group of researchers, including those from Indigenous groups, this baseless statistic could be undermining the conservation efforts of the Indigenous People it’s meant to support and prevent further work to really understand how best to conserve biodiversity.Two of the authors joined us to discuss how this statistic gained traction, the harm it could cause, and how better to support the work of Indigenous Peoples.Read more in a Comment article from the authors: No basis for claim that 80% of biodiversity is found in Indigenous territoriesSubscribe to Nature Briefing, an unmissable daily round-up of science news, opinion and analysis free in your inbox every weekday.Never miss an episode. Subscribe to the Nature Podcast on Apple Podcasts, Spotify, YouTube Music or your favourite podcast app. An RSS feed for the Nature Podcast is available too. More

Tsimane’ people in the Bolivian Amazon weave palm leaves together to thatch dwellings.Credit: Joan de la Malla

For the past 20 years or so, a claim has been made in all sorts of outlets, from reports and scientific publications to news articles, that 80% of the world’s biodiversity is found in the territories of Indigenous Peoples. Those using this figure invariably aim to highlight the essential roles that Indigenous Peoples have in conserving biodiversity, and seem to have quoted it in the belief that it is based on solid science.Numerous studies demonstrate that Indigenous Peoples and their territories are indeed key to safeguarding biodiversity for future generations1,2. But the claim that 80% of the world’s biodiversity is found in Indigenous Peoples’ territories is wrong.
Indigenous knowledge is key to sustainable food systems
The continued use of this number by United Nations agencies, non-governmental organizations (NGOs), journalists, conservation biologists and Indigenous activists and advocates, among others, could damage the exact cause that it is being used to support. Efforts to draw on and prioritize Indigenous Peoples’ knowledge in biodiversity conservation, and to protect their governance and rights, could be undermined if the credibility of individuals and organizations who make this claim is questioned.The global conservation community must abandon the 80% claim and instead comprehensively acknowledge the crucial roles of Indigenous Peoples in stewarding their lands and seas — and must do so on the basis of already available evidence.Fact or fiction?The 80% claim is based on two assumptions: that biodiversity can be divided into countable units, and that these can be mapped spatially at the global level. Neither feat is possible, despite important advances in measuring biodiversity3. In fact, according to the Convention on Biological Diversity — a multilateral treaty to develop strategies for the conservation and sustainable use of biological diversity, involving nearly 200 countries — biodiversity is the “diversity within species, between species and of ecosystems”4. It is not something that can be easily quantified.Even if researchers resorted to using the number of species present as a measure of biodiversity — a narrow yet common proxy — there are still millions of species that have not been described. Furthermore, there is debate over the proportion of described taxa that represents valid species, and knowledge about the geographical distributions of most species is lacking or incomplete. Data on species counts and distributions are especially likely to be missing for Indigenous Peoples’ lands and seas.

A traditional rice terrace built by members of the Torajan people in Sulawesi, Indonesia.Credit: Joan de la Malla

The 80% claim seems to stem from misinterpretations of previously published statements. As advocates for Indigenous Peoples (three of us identify as Indigenous), we have had discussions about this figure over several years with Indigenous leaders at policy forums, on field visits and in research projects. To track its origins and assess how frequently it has been cited in the literature and in what contexts, we searched for combinations of the words ‘Indigenous’, ‘80%’ and ‘biodiversity’, as well as for combinations of their variants, such as ‘eighty’, ‘percent’ and ‘biological diversity’. We conducted our search using Google Scholar and Clarivate’s Web of Science, and included literature published up to 1 August this year.Our search found no reference to the 80% assertion before 2002. A report that year by the UN Commission on Sustainable Development, a body tasked with assessing progress on the commitments agreed at the 1992 UN Conference on Environment and Development in Rio de Janeiro, Brazil, stated that Indigenous Peoples “nurture 80% of the world’s biodiversity on ancestral lands and territories”5. Over the next six years, similar unattributed statements were made in four other reports (see Supplementary information). However, judging by how commonly the number is cited, it seems to have been a 2008 World Bank report6 that contributed most to its widespread adoption in the academic literature (see ‘Poor fact-checking’).

Source: Analysis by Á. Fernández-Llamazares et al.

On the basis of the citations we tracked in our literature review, the earliest potential source for the 80% claim that we could identify is a chapter in the 2001 edition of the Encyclopedia of Biodiversity7. Three documents cite this publication, including a 2009 report by the Food and Agricultural Organization of the UN (FAO)8. It states: “Approximately 80 percent of the world’s remaining biodiversity is found in indigenous peoples’ territories.” But the encyclopedia actually asserts that “nearly 80% of the terrestrial ecoregions are inhabited by one or more indigenous peoples”7. In other words, the original statement, along with the analysis underpinning it, merely quantified the proportion of the world’s 136 terrestrial ecoregions in which Indigenous Peoples were living.The influential World Bank report6 does not cite the encyclopedia, but instead gives the source as a 2005 publication by the World Resources Institute (WRI), a global non-profit research organization in Washington DC. However, the closest the WRI publication comes to supporting the statement is the observation that seven Indigenous communities in the Philippines were “maintaining over 80 percent of the original high-biodiversity forest cover”9.Out of nowhereAmong the 348 documents that we found to include the 80% claim are 186 peer-reviewed journal articles, including some in BioScience, The Lancet Planetary Health and Philosophical Transactions of the Royal Society, and 19 news articles targeted at a specialist audience, including one in Nature (see Nature https://doi.org/ndqf (2024) and Supplementary information). The claim has been repeated by the Convention on Biological Diversity10 and by NGOs such as the conservation group WWF. One study in the Proceedings of the National Academy of Sciences even states that Indigenous Peoples “protect approximately 85% of the world’s biodiversity through stewardship”11.

Maasai women in Kenya lead a community-based rangeland restoration project.Credit: Joan de la Malla

The 80% figure has also gained attention in the wider media and has entered popular culture. For instance, the film-maker James Cameron used it in 2022 when publicizing his film franchise Avatar. It has become so engrained in public discourse that even the online fact-checking service GigaFact confirms it to be true (see go.nature.com/4cwxgcd).
Weaving Indigenous knowledge into the scientific method
In our literature review, we found only two documents that questioned the claim: a blog post (see go.nature.com/4dqbavs) and a footnote in a policy brief by the ICCA Consortium, an organization that promotes recognition of the territories of Indigenous Peoples and local communities12. Some Indigenous Peoples’ representatives acknowledge that they have been unable to find supporting evidence for the claim. And some Indigenous leaders have told us that they avoid endorsing the figure.Our criticism of the 80% claim should in no way undermine decades of effort by Indigenous Peoples’ organizations and others to influence international biodiversity and climate policy. Nor should it detract from the essential and verifiably considerable part that Indigenous Peoples play in the conservation of the planet’s biodiversity. For example, a 2018 analysis13 led by one of us (S.T.G.) indicated that, at the time, Indigenous Peoples managed or held tenure rights over more than one-quarter of Earth’s terrestrial surface — land that intersected with at least 37% of the remaining natural lands worldwide (see ‘Fact, not fiction’).

Source: Ref. 13

Subsequent studies have shown that Indigenous Peoples’ lands include more than one-third of the world’s intact forest landscapes (forest ecosystems that show little sign of habitat conversion or fragmentation)1,2,14,15. And around 60% of all terrestrial mammals for which reliable habitat data exist (comprising more than 2,500 species) have more than 10% of their ranges in Indigenous Peoples’ lands16. Compared with protected areas, these lands support at least as many species (when matched for habitat type, location and so on), have fewer alien species and have retained a similar proportion of habitat2,14,15. Indeed, in the past five years, the essential roles of Indigenous Peoples in global biodiversity conservation have been recognized in numerous landmark reports3,17.On the contrary, our concern is that the 80% claim could undermine these and other rigorous studies — as well as effective efforts to conserve biodiversity by Indigenous Peoples on the ground. Putting aside the fundamental problems with this specific statistic, trying to assign a numerical value to biodiversity on Indigenous Peoples’ territories fails to represent Indigenous values and world views in a meaningful way.More than a numberThe integral connections between Indigenous Peoples and their lands, seas and resources help to conserve biodiversity worldwide in varied ways3,17. This is apparent from scholarship that draws on Indigenous Knowledge across cultures, from oral narratives passed down through generations, and from cultural practices to manage biodiversity17. Assessing the impact of Indigenous Peoples on the safeguarding of biodiversity requires taking into account the many complex interrelations between humans and non-human nature, not just the number of species and ecosystems in a region.

Tsimane’ women in Bolivia make baskets using the leaves of a palm tree.Credit: Joan de la Malla

The implicit assumption behind the 80% claim is that the characterization of biodiversity is complete. Indeed, the implied certainty suggests that Indigenous scholarship and Indigenous Knowledge systems might not be needed to improve understanding of the state of biodiversity on Indigenous Peoples’ lands and in their seas. Although Indigenous Knowledge holders and scholars have long understood the importance of Indigenous governance for the stewardship of biodiversity, an understanding of this is only just beginning to develop among the broader public.The global conservation community must abandon the unsupported 80% claim, and instead acknowledge more comprehensively the crucial roles of Indigenous Peoples in biodiversity conservation, restoration and stewardship. This means acting in partnership with and supporting the leadership of Indigenous Peoples, recognizing their rights to their lands and seas, and involving them as leaders or as equal partners in decision-making. It means amplifying Indigenous voices in international biodiversity and climate-change forums, and providing Indigenous Peoples with resources so that they can lead their own conservation initiatives.Genuinely valuing and integrating the ecological knowledge of Indigenous Peoples will lead to a more just and effective approach to conserving the planet’s biodiversity. More

Genetic diversity is essential to biodiversity. When environmental conditions change, as with global warming, genetic modifications under natural selection help to prevent populations and species, especially of sessile organisms such as plants, from extirpation. Governments and conservation authorities worldwide must do more to set aside areas where natural selection can occur without human intervention.
Competing Interests
The authors declare no competing interests. More

Peter Bridgewater et al. call for the International Whaling Commission (IWC) to be dismantled because it has “so little to show” since the moratorium on commercial whaling began in 1985 (P. Bridgewater et al. Nature 632, 500–502; 2024). I have attended numerous IWC meetings as both a governmental delegate and an observer. The authors are wrong.
Competing Interests
The author declares no competing interests. More