About the Authors

Brian J. Greco

bjgreco@ucdavis.edu

Affiliations Department of Animal Science and Center for Animal Welfare, University of California Davis, Davis, California, United States of America, AWARE Institute, Portland, Oregon, United States of America

Cheryl L. Meehan

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

Lance J. Miller

Affiliation Chicago Zoological Society—Brookfield Zoo, Brookfield, Illinois, United States of America

David J. Shepherdson

Affiliation Oregon Zoo, Portland, Oregon, United States of America

Kari A. Morfeld

Affiliation Smithsonian Conservation Biology Institute, National Zoological Park, Front Royal, Virginia, United States of America

Jeff Andrews

Affiliation Busch Gardens, Tampa, Florida, United States of America

Anne M. Baker

Affiliation CBSG North America, Apple Valley, Maine, United States of America

Kathy Carlstead

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

Joy A. Mench

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

Competing Interests

LM is affiliated with the Chicago Zoological Society – Brookfield Zoo (an AZA-accredited zoo), DS is affiliated with Oregon Zoo (an AZA-Accredited zoo), and JA is affiliated with Busch Gardens (an AZA-accredited zoo). KC was employed by the Honolulu Zoo (an AZA-accredited zoo) at the time of the study. KM is affiliated with the Smithsonian National Zoo (an AZA-accredited zoo) and was employed by the Lincoln Children’s Zoo (an AZA-accredited zoo) at the time of the study. JM is a member of the PLOS ONE Animal Research Advisory Group. CM and BG 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. 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

Conceived and designed the experiments: CLM BJG JA KC LJM DJS JAM KAM AB. Performed the experiments: CLM. Analyzed the data: BJG LJM CLM. Contributed reagents/materials/analysis tools: BJG CLM LJM JAM. Wrote the paper: BJG CLM JAM LJM DJS.