Global importance of Indigenous Peoples, their lands, and knowledge systems for saving the world's primates from extinction

Abstract

Primates, represented by 521 species, are distributed across 91 countries primarily in the Neotropic, Afrotropic, and Indo-Malayan realms. Primates inhabit a wide range of habitats and play critical roles in sustaining healthy ecosystems that benefit human and nonhuman communities. Approximately 68% of primate species are threatened with extinction because of global pressures to convert their habitats for agricultural production and the extraction of natural resources. Here, we review the scientific literature and conduct a spatial analysis to assess the significance of Indigenous Peoples' lands in safeguarding primate biodiversity. We found that Indigenous Peoples' lands account for 30% of the primate range, and 71% of primate species inhabit these lands. As their range on these lands increases, primate species are less likely to be classified as threatened or have declining populations. Safeguarding Indigenous Peoples' lands, languages, and cultures represents our greatest chance to prevent the extinction of the world's primates.

Fig. 1.. Selected primate species in the Neotropics, Afrotropics, and Indo-Malayan realm whose distributional ranges intersect Indigenous Peoples’ lands.

Shown also is their IUCN conservation status (CR, Critically Endangered; VU, Vulnerable; EN, Endangered; LC, Least Concern). (A) Neotropics: 1, Northern muriqui (Brachyteles hypoxanthus), CR (photo credit: Priscila Pereira); 2, Colombian night monkey (Aotus lemurinus), VU (photo credit: Juan Felipe León León); 3, Black-capped capuchin (Sapajus apella), LC (photo credit: Joan de la Malla); 4, Munduruku marmoset (Mico munduruku), VU (photo credit: Marlyson Costa. (B) Afrotropics: 1, Western gorilla (Gorilla gorilla), CR (photo credit: Rhett Butler); 2, Grivet monkey (Cholorocebus aethiops), LC (photo credit: Sarie Van Belle); 3, Western chimpanzee (Pan troglodytes), CR (photo credit: K.H.); 4, Spectacled Lesser Galago (Galago matschiei), LC (photo credit: Yvonne A. de Jong and Thomas M. Butynski). (C) Indo-Malay: 1, Sumatran orangutan (Pongo abelii), CR (photo credit: Perry van Duijnhoven); 2, White-headed langur (Trachypithecus poliocephalus), EN (photo credit Paul A. Garber); 3, Philippine Slow Loris (Nycticebus menagensis), VU (photo credit: Hery Sudarno); 4, Skywalker gibbon (Hoolock tianxing), EN (photo credit: Fan Peng-Fei). See tables S3 to S5 for spatial metrics for each of these species.

Fig. 2.. Indigenous Peoples’ sustainable use of natural resources.

(A) Summary of critical concepts in Indigenous Peoples’ sustainable use of natural resources favoring biodiversity and primate conservation. Indigenous Peoples’ knowledge systems are transmitted orally from generation to generation (61). (B) Example of ecological engineering by Lancandon Indigenous Peoples of southern Mexico involving the sustainable use of natural resources. “Milpa” is a crop-growing system used throughout Mesoamerica. Lacandon Indigenous Peoples’ flow diagram based on information in (247). Photo by A.E. taken with Lacandon Indigenous Peoples’ informed consent.

Fig. 3.. Global geographic overlap among primate distributions, Indigenous Peoples’ lands, and protected areas.

The primate species range data source was the IUCN Red List 2021. The number of primate species per realm is indicated to the immediate right or left of that region. We defined species richness as the overlap of the polygons describing the geographic distributions of all primate species onto a cell grid of 0.5° resolution in latitude and longitude. Numbers by each region refer to the number of primate species present. The source of data on Indigenous Peoples’ lands is from (21). Protected areas from Protected Planet (50). For this spatial analysis, we did not separate protected areas into their different categories; we considered categories I to VI as a group. The resolution may be inexact because boundaries between Indigenous and other lands are often contested. Given Madagascar’s unique situation regarding no Indigenous Peoples, we estimated that its primate range encompasses an area of ~0.469 million km² or 80% of Madagascar’s land area (ca 587,041 km²); protected areas account for 17% of the primate range and other lands 83% (Table 1 and fig. S5).

Fig. 4.. Spatial distribution of Indigenous Peoples’ lands and the conservation status of primate species that inhabit these lands.

(A) Euler plots of the intersection between Indigenous Peoples’ lands (IPLs) and protected areas (PAs) across the distributional range of primates globally and in each realm. Circles and areas of intersection in the global and ecoregion plots are proportional to the area of the natural range of primates (global, ~46 million km²; Neotropics, ~14 million km²; mainland Africa, ~20 million km²; Indo-Malayan realm, ~12 million km²; Table 1). (B) Boxplots showing the global percent of primate species (n = 362) whose ranges intersect with IPLs, PAs, and other lands (OLs). Other lands may include non-Indigenous community lands and protected areas not included in the World Database on Protected Areas (21, 50). (C) Global percent of primate species whose range does not intersect Indigenous Peoples’ lands (n = 151; Neotropics, 5 species; mainland Africa, 20 species; Madagascar, 107 species; and Indo-Malayan realm, 19 species). Also shown for these species is the percent of their range that intersects PAs and OLs (table S5). Boxplots for the Neotropics, mainland Africa, and Indo-Malayan region are presented in fig. S2. Original data are in tables S2 to S4. (D) Percent of primate species whose range overlaps with Indigenous Peoples’ lands’ and their IUCN conservation category. (E) Percent of primate species whose range overlaps with Indigenous Peoples’ lands and their IUCN population trend. IUCN conservation categories: DD, Data Deficient; LC, Least Concerned; NT, Near Threatened; VU, Vulnerable; EN, Endangered; CR, Critically Endangered; UK, Unknown; INCR, Increasing; STA, Stable; DECR, Decreasing. Source of IUCN data IUCN Red List (https://iucnredlist.org/). Bar graphs include the species from Madagascar since their ranges do not overlap Indigenous Peoples’ lands. See tables S2 to S6 for data on primate species in each primate range region.

Fig. 5.. Percent of primate ranges across all primate range countries that overlap with IPLs, PAs, and OLs.

(A) IPLs, (B) PAs, and (C) OLs (table S1). PAs refer to IUCN categories I to VI. Country profiles of IPLs and PAs in fig. S2. Original data in table S1. Primate silhouettes from www.phylopic.org.

Fig. 6.. The Human Footprint, infrastructure density, Indigenous Peoples’ lands, and primate geographic distributions.

(Top) Frequency of intact lands, i.e., areas with a Human Footprint <4, within IPLs and on lands immediately adjacent to IPLs: up to 10 km from IPL borders, 10 to 25 km from IPL borders, and 25 to 50 km from IPL borders, across the Neotropic, African, and Indo-Malayan realms. (Bottom) Infrastructure distribution across the Legal Amazon of Brazil (dark gray area in the inset). Infrastructure data were obtained from MapBiomas (https://mapbiomas.org/en) and OpenStreetMap (https://openstreetmap.org/#map=4/38.01/-95.84). Together with state and federal roads, we also show energy infrastructures, mining areas, waterways (used for people and cargo transportation), main cities (size proportional to population), energy plants, and aerodromes. BR-319 is highlighted by the red arrow. IPLs and PAs are from TerraBrasilis (URL: terrabrasilis.dpi.inpe.br; accessed in May 2021). The road data in OpenStreetMap are ~83% complete. Therefore, our results may underestimate the extent of roads in the Brazilian Amazon. See fig. S6, Supplementary Text, and (248) for procedures.

Fig. 7.. Major global socioeconomic pressures on IPLs.

(Left) Primary factors negatively affect the ecological integrity and ownership of IPLs resulting in land dispossession. (Right) Key consequences of land dispossession on Indigenous Peoples’ knowledge systems, culture, symbolic life, and well-being.

Fig. 8.. Key global societal actions needed to support Indigenous People.

These actions will enable Indigenous Peoples to continue their land stewardship and culture in ways that will benefit primate conservation. In general, these actions apply to all primate range nations. Ultimately, it will be Indigenous people who decide whether their engagement with their lands will allow them to continue their traditional ways of life—the actions indicated above will make it possible for them to have that option.