[1] Univ Zurich, Dept Evolutionary Biol & Environm Studies, CH-8057 Zurich, Switzerland
[2] Australian Natl Univ, Res Sch Biol, Canberra, ACT 2600, Australia
[3] Max Planck Inst Anim Behav, Cognit & Cultural Ecol Res Grp, Radolfzell Am Bodensee, ACT, Germany
[4] Max Planck Inst Anim Behav, Cognit & Cultural Ecol Res Grp, D-78315 Radolfzell am Bodensee, Germany
[5] Max Planck Inst Anim Behav, Collect Migrat Grp, D-78315 Constance, Germany
[6] Inst Univ, Ecoethol Res Unit, ISPA, P-1149041 Lisbon, Portugal