[1] Ctr Ecol & Hydrol, Nat Environm Res Council, Wallingford OX10 8BB, Oxon, England
[2] Newcastle Univ, Sch Biol, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England
[3] Tero Ltd, Thessaloniki 57001, Greece
[4] Aristotle Univ Thessaloniki, Fac Agr, Thessaloniki 54124, Greece
[5] Stockholm Univ, Stockholm Resilience Ctr, S-10691 Stockholm, Sweden
[6] Durrell Wildlife Conservat Trust, Trinity JE3 5BP, Jersey, Wales
[7] Univ Florence, Econ Sci Dept, Int Union Conservat Nat, I-50127 Florence, Italy
[8] Fdn Yangareko, Yangareko, Santa Cruz, Bolivia
[9] OT Boxdorf, D-01468 Moritzburg, Germany
[10] Ind Econ, Cambridge, MA 02140 USA
[11] Maine Dept Inland Fisheries & Wildlife, Augusta, ME 04333 USA
[12] Enveco, S-12748 Skarholmen, Sweden
[13] Univ Debrecen, Ctr Environm Management & Policy, H-4032 Debrecen, Hungary
[14] Danube Delta Natl Inst, Tulcea 820112, Romania
[15] Ecol Inst, D-10717 Berlin, Germany
[16] Int Union Conservat Nat, London NW6 6LN, England
[17] Int Union Conservat Nat, Belgrade 11070, Serbia
[18] Game & Wildlife Conservat Trust, Fordingbridge SP6 1EF, Hamps, England
[19] Univ Cambridge, Dept Geog, Cambridge CB2 3EN, England
[20] Univ Oxford, Dept Zool, Oxford OX1 3PS, England