Funding for this research was provided by:
National Science Foundation USA (BCS #0409367)
National Science Foundation (IOS #0719003)
Trinity College of Arts and Sciences, Duke University
Received: 27 October 2018
Accepted: 21 July 2019
First Online: 22 August 2019
Ethics approval and consent to participate
: The research protocols were approved by the Institutional Animal Care and Use Committee of Duke University (protocol numbers A245–03-07 & A143–12-05) and by the research directors of Cincinnati Zoo & Botanical Garden and the Indianapolis Zoo. Written informed consent to have zoo animals participate in this study was given by the research directors of each zoo after approval of the protocols.
: Not applicable.
: The authors declare that they have no competing interests.