About the Authors

Vincent Nijman

vnijman@brookes.ac.uk

Affiliation Oxford Wildlife Trade Research Group, Oxford Brookes University, OX3 0BP, Oxford, United Kingdom

Denise Spaan

Affiliations Oxford Wildlife Trade Research Group, Oxford Brookes University, OX3 0BP, Oxford, United Kingdom, Institute of Neuroethology, University of Veracruz, Xalapa, Mexico

K. Anne-Isola Nekaris

Affiliation Oxford Wildlife Trade Research Group, Oxford Brookes University, OX3 0BP, Oxford, United Kingdom

Competing Interests

The study was funded in part by two commercial funders, Dierenpark Amsterfoort and Cleveland Zoo. This does not alter the authors' adherence to all PLOS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: VN DS KAIN. Analyzed the data: VN KAIN. Contributed reagents/materials/analysis tools: VN DS KAIN. Wrote the paper: VN DS KAIN.