About the Authors

Cheryl L. Meehan

Cheryl.meehan@aware.institute

Affiliation AWARE Institute, Portland, Oregon, United States of America

Joy A. Mench

Affiliations Center for Animal Welfare, University of California Davis, Davis, California, United States of America, Department of Animal Science, University of California Davis, Davis, California, United States of America

Kathy Carlstead

Affiliation Honolulu Zoo Society, Honolulu, Hawaii, United States of America

Jennifer N. Hogan

Affiliation AWARE Institute, Portland, Oregon, United States of America

Competing Interests

JM is involved in the Animal Research Advisory Group at PLOS ONE. CM and JH are affiliated with AWARE Institute. AWARE Institute is a commercial entity founded by CM in 2014 and provides animal welfare assessment, research and education services to zoos and aquariums. KC was employed by the Honolulu Zoo (an AZA-accredited zoo) at the time of the study. These interests do not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials, as detailed online in the guide for authors.

Author Contributions

Analyzed the data: CLM JNH. Wrote the paper: CLM JAM KC JNH.