Abstract
Surveying great ape populations is time-consuming and costly, and often relies on generalised parameters, resulting in imprecise population estimates. Using thermal imaging, through thermal cameras fitted on unmanned aerial vehicles, to detect primates directly from the air, may prove a useful alternative to conventional great ape population surveys. This may be especially true for bonobos (Pan paniscus) which, due to their large body size and nesting behaviour, could provide a uniquely identifiable thermal signature. We trialled the use of a thermal drone to record bonobos in their natural environment in the Democratic Republic of Congo, as a first step towards using the technique to survey great apes. Bonobos were observed asleep in their nests during all surveys at different flight speeds and heights, showing potential for the use of thermal drones as a method to survey great apes.
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Acknowledgements
We thank WWF Belgium and WWF DRC for help with logistics, fieldwork, and project funding. We are very grateful to Willy Mbemba, Junior Batangeli and Vedas Ngwanza for guidance in the field, and the commune chiefs of Mbanzi, Louvua, and Mongama for allowing us to conduct research in their respective regions. This project was made possible with support from the Belgian Directorate-General for Development Cooperation and Humanitarian Aid (DGD). Finally, we would like to thank the journal’s editor, two anonymous reviewers, Tom Martin, and Martijn van Roie for their invaluable comments on previous versions of this manuscript.
Funding
This study was funded by WWF Belgium, WWF DRC and the Belgian Directorate-General for Development Cooperation and Humanitarian Aid (DGD).
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Handling Editor: Joanna M. Setchell
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van Berkel, T., Dahms, T., Mbende, M. et al. Detection of Bonobos (Pan Paniscus) in Tropical Rainforest Canopies Using Drone-Based Thermal Imaging: A First Step Towards Accurately Estimating Population Sizes?. Int J Primatol 44, 240–244 (2023). https://doi.org/10.1007/s10764-022-00334-7
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DOI: https://doi.org/10.1007/s10764-022-00334-7