About the Authors

Sue Anne Zollinger

saz@sueannezollinger.com

Affiliations Communication and Social Behaviour Group, Max Planck Institute for Ornithology, Seewiesen, Germany, School of Biology, University of St Andrews, St Andrews, Fife, United Kingdom

Franz Goller

Affiliation Department of Biology, University of Utah, Salt Lake City, Utah, United States of America

Henrik Brumm

Affiliation Communication and Social Behaviour Group, Max Planck Institute for Ornithology, Seewiesen, Germany

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: SAZ FG HB. Performed the experiments: SAZ. Analyzed the data: SAZ. Contributed reagents/materials/analysis tools: FG. Wrote the paper: SAZ.