1. Theodore E. Squires, Faculty of Natural Resource Sciences, University of Akeyuri, Norðurslóð, 600 Akeyuri, Iceland, and Dept. of Ecology and Genetics, Animal Ecology, Uppsala University, Norbyvägen 16, 752 36 Uppsala, Sweden, e-mail: .
2. Alexander L. Bond, Bird Group, Natural History Museum, Akeman Street, Tring, Herts. HP23 6AP, UK, e-mail: