1. Adam Scott Kennedy, e-mail: .
2. Peter Boesman, Duinenweg 3, B-2820 Rijmenam, Belgium.
3. N. J. Collar, BirdLife International, Pembroke Street, Cambridge CB2 3QZ, UK, and Bird Group, Dept. of Life Sciences, Natural History Museum, Tring, Herts. HP23 6AP, UK, e-mail: .
4. Lincoln D. C. Fishpool, 12 Mountain Street, Chilham, Canterbury, Kent CT4 8DQ, UK.