Journal article

First integrative trend analysis for a great ape species in Borneo

Truly Santika, Marc Ancrenaz, Kerrie A Wilson, Stephanie Spehar, Nicola Abram, Graham L Banes, Gail Campbell-Smith, Lisa Curran, Laura d'Arcy, Roberto A Delgado, Andi Erman, Benoit Goossens, Herlina Hartanto, Max Houghton, Simon J Husson, Hjalmar S Kuehl, Isabelle Lackman, Ashley Leiman, Karmele Llano Sanchez, Niel Makinuddin Show all



For many threatened species the rate and drivers of population decline are difficult to assess accurately: species' surveys are typically restricted to small geographic areas, are conducted over short time periods, and employ a wide range of survey protocols. We addressed methodological challenges for assessing change in the abundance of an endangered species. We applied novel methods for integrating field and interview survey data for the critically endangered Bornean orangutan (Pongo pygmaeus), allowing a deeper understanding of the species' persistence through time. Our analysis revealed that Bornean orangutan populations have declined at a rate of 25% over the last 10 years. Survival rat..

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Funding Acknowledgements

This study is part of "Borneo Futures" initiative. Funding for this collaborative work is provided in the Supplementary Data. We are greatly indebted to all orangutan researchers and wildlife personnel whose efforts were valuable in data collection, and for making this study possible. We also thank the governments of Indonesia and Malaysia, and their forest and environmental departments, for supporting this research.