[1] Netherlands Inst Ecol, NL-6666 ZG Heteren, Netherlands
[2] Russian Acad Sci, Karelian Res Ctr, Inst Biol, Petrozavodsk 185610, Russia
[3] Cardiff Univ, Sch Biosci, Llysdinam Field Ctr, Newbridge On Wye LD1 6ND, Llandrindod, Wales
[4] Univ Turku, Sect Ecol, Turku 20014, Finland
[5] Univ Gothenburg, Dept Zool, SE-40530 Gothenburg, Sweden
[6] Evolutionary Biol Ctr, Dept Anim Ecol, SE-75236 Uppsala, Sweden
[7] Moscow MV Lomonosov State Univ, Zvenigorod Biol Stn, Moscow 143036, Russia
[8] Univ Helsinki, Kilpisjarvi Biol Stn, FIN-00014 Helsinki, Finland
[9] Univ Glasgow, Ornithol Grp, Div Environm & Evolutionary Biol, Glasgow G12 8QQ, Lanark, Scotland
[10] Umea Univ, Dept Ecol & Environm Sci, S-90187 Umea, Sweden
[11] Univ Alcala de Henares, Dept Anim Biol, E-288871 Alcala De Henares, Spain
[12] Museo Nacl Ciencias Nat, CSIC, Dept Ecol Evolut, Madrid, Spain
[13] Cardiff Univ, Cardiff Sch Biosci, Cardiff CF10 1XL, S Glam, Wales
[14] Russian Acad Sci, Inst Zool, Biol Stn Rybachy, Kaliningrad 238535, Russia
[15] Eotvos Lorand Univ, Behav Ecol Grp, Dept Systemat Zool & Ecol, H-1117 Budapest, Hungary
[16] Inst Avian Res Vogelwarte Helgoland, Working Grp Populat Ecol, D-38162 Cremlingen, Germany
[17] Univ Wales, Sch Biol Sci, Bangor LL57 2UW, Gwynedd, Wales