1. Department of Ornithology, Aranzadi Society of Sciences, Donostia-S. Sebastián, Spain
2. Environment Canada, Saskatoon, Canada
3. SEO/BirdLife-Málaga, Campanillas (Málaga), Spain
4. Arcachon Marine Station, University of Bordeaux 1, Arcachon, France
5. Départment de Biologie, Université Chouaib Doukkali, El Jadida, Morocco
6. Apdo. 94, Silves, Portugal
7. SEO/BirdLife-Valencia, Alboraia (Valencia), Spain