Global opportunities and challenges for transboundary conservation.

Rapid biodiversity loss has prompted global action to prevent further declines, yet coordinated conservation action among nations remains elusive. As a result, species with ranges that span international borders-which include 53.8% of terrestrial birds, mammals and amphibians-are in increasing peril through uncoordinated management and artificial barriers to human movement, such as border fences. Transboundary conservation initiatives represent a unique opportunity to better protect species through coordinated management across national borders. Using metrics of governance, collaboration and human pressure, we provide an index of transboundary conservation feasibility to assess global opportunities and challenges for different nations. While the transboundary conservation potential of securing multinational threatened species varied substantially, there are distinct opportunities in South-East Asia, Northern Europe, North America and South America. But to successfully avert the loss of transboundary species, the global community must be prepared to invest in some regions facing greater implementation challenges, including the nations of Central Africa, where efforts may necessitate establishing rapid conservation interventions postconflict that align with local socio-cultural opportunities and constraints. Sanctioned and coordinated approaches towards managing transboundary species are now essential to prevent further declines of many endangered species, and global policy efforts must do more to produce and enact legitimate mechanisms for collaborative action in conservation.