1. Estación Biológica de Doñana (EBD-CSIC), Avda. Américo Vespucio 26, Isla de la Cartuja, 41092 Sevilla, Spain
2. Centre for Biodiversity and Biosecurity, School of Biological Sciences, The University of Auckland, Auckland, New Zealand
3. Landcare Research, Auckland, New Zealand
4. Andrena Iniciativas y Estudios Medio Ambientales, Valladolid, Spain