[1] CSIC CTFC CREAF, CEMFOR, CTFC, InForest Joint Res Unit, Solsona 25280, Spain
[2] CREAF, Cerdanyola Del Valles 08193, Spain
[3] Univ Lausanne, Dept Ecol & Evolut, CH-1015 Lausanne, Switzerland
[4] Nat Hist Museum Barcelona, Catalan Ornithol Inst, European Bird Census Council, Placa Leonardo da Vinci 4-5, Barcelona 08019, Spain
[5] Univ Lausanne, Inst Earth Surface Dynam, Geopolis, CH-1015 Lausanne, Switzerland
[6] CSIC, Cerdanyola Del Valles 08193, Spain