About the Authors

Natalia Pitala

Affiliations Bird Ecology Unit, Department of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland, Department of Animal Ecology/Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden

Heli Siitari

Affiliation Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland

Lars Gustafsson

Affiliation Department of Animal Ecology/Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden

Jon E. Brommer

jon.brommer@helsinki.fi

Affiliation Bird Ecology Unit, Department of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: NP JEB. Performed the experiments: NP JEB. Contributed reagents/materials/analysis tools: HS LG. Wrote the paper: NP HS JEB.