Indigenous lands are slightly more species rich than existing protected areas. In Brazil and Canada, Indigenous lands support more threatened species. Enhanced partnerships between Indigenous communities and federal or state governments could help.
Declines in global biodiversity due to land conversion and habitat loss are driving a \"Sixth Mass Extinction\" and many countries currently fall short of meeting even nominal land protection targets to mitigate this crisis. Here, we quantify the potential contribution of Indigenous lands to biodiversity conservation using case studies of Australia, Brazil and Canada. Indigenous lands in each country are slightly more species rich than existing protected areas and, in Brazil and Canada, support more threatened species than existing protected areas or random sites. These results indicate that Indigenous lands and existing protected areas are similar in biodiversity. Enhanced partnerships between Indigenous communities and federal or state governments could help ameliorate current shortfalls in global biodiversity protection by facilitating protection for native species, helping to stem global biodiversity loss.