About the Authors

Angela S. Stoeger
Department of Cognitive Biology, University of Vienna, Vienna, Austria

Gunnar Heilmann
Gfai tech GmbH, Berlin, Germany

Matthias Zeppelzauer
Institute for Software Technology and Interactive Systems, Vienna University of Technology, Vienna, Austria

André Ganswindt
Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, South Africa

André Ganswindt
Section of Reproduction, Department of Production Animal Studies, University of Pretoria, Onderstepoort, South Africa

Sean Hensman
Adventures with Elephants, Bela Bela, South Africa

Benjamin D. Charlton
School of Psychology, University of Sussex, Brighton, United Kingdom

Corresponding Author

angela.stoeger-horwath@univie.ac.at

Competing Interests

Since two authors (Gunnar Heilman and Sean Hensman) are employed commercial companies the authors want to declare that they did not pay for using the equipment nor for doing research with the elephant at Bela Bela. Therefore, both companies had no financial interest concerning the research. The fact that these authors are employed by these companies does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: ASS GH. Performed the experiments: ASS GH SH AG. Analyzed the data: ASS MZ. Contributed reagents/materials/analysis tools: ASS MZ. Wrote the paper: ASS BDC.